From bca92962dea61126a45d11aba476a64d97ae8824 Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Wed, 2 Feb 2022 20:55:40 +0100
Subject: [PATCH 01/23] Move Role::ConfigReader to Role::Config

Role::Config is the configuration part of an object
Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 lib/Dancer2/Core/Role/{ConfigReader.pm => Config.pm} | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename lib/Dancer2/Core/Role/{ConfigReader.pm => Config.pm} (100%)

diff --git a/lib/Dancer2/Core/Role/ConfigReader.pm b/lib/Dancer2/Core/Role/Config.pm
similarity index 100%
rename from lib/Dancer2/Core/Role/ConfigReader.pm
rename to lib/Dancer2/Core/Role/Config.pm

From 743485cc4a327310f7611d063a2fa447a0d63854 Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Wed, 2 Feb 2022 20:57:22 +0100
Subject: [PATCH 02/23] Create Role::Config to be the "config" part of obj

Remove everything that has to do with loading config
from files or elsewhere.

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 lib/Dancer2/Core/App.pm         |   2 +-
 lib/Dancer2/Core/Role/Config.pm | 149 +++++++++++++++++---------------
 2 files changed, 80 insertions(+), 71 deletions(-)

diff --git a/lib/Dancer2/Core/App.pm b/lib/Dancer2/Core/App.pm
index af1147040..3413552e7 100644
--- a/lib/Dancer2/Core/App.pm
+++ b/lib/Dancer2/Core/App.pm
@@ -39,7 +39,7 @@ our $EVAL_SHIM; $EVAL_SHIM ||= sub {
 # we have hooks here
 with qw<
     Dancer2::Core::Role::Hookable
-    Dancer2::Core::Role::ConfigReader
+    Dancer2::Core::Role::Config
 >;
 
 sub supported_engines { [ qw<logger serializer session template> ] }
diff --git a/lib/Dancer2/Core/Role/Config.pm b/lib/Dancer2/Core/Role/Config.pm
index 0d0bc1abe..fec20ec01 100644
--- a/lib/Dancer2/Core/Role/Config.pm
+++ b/lib/Dancer2/Core/Role/Config.pm
@@ -1,5 +1,5 @@
 # ABSTRACT: Config role for Dancer2 core objects
-package Dancer2::Core::Role::ConfigReader;
+package Dancer2::Core::Role::Config;
 
 use Moo::Role;
 
@@ -7,7 +7,7 @@ use File::Spec;
 use Config::Any;
 use Hash::Merge::Simple;
 use Carp 'croak';
-use Module::Runtime 'require_module';
+use Module::Runtime qw{ require_module use_module };
 
 use Dancer2::Core::Factory;
 use Dancer2::Core;
@@ -66,6 +66,13 @@ has config_files => (
     builder => '_build_config_files',
 );
 
+has config_readers => (
+    is      => 'ro',
+    lazy    => 1,
+    isa     => ArrayRef,
+    builder => '_build_config_readers',
+);
+
 has local_triggers => (
     is      => 'ro',
     isa     => HashRef,
@@ -84,9 +91,11 @@ has global_triggers => (
             },
         };
 
+        no warnings 'once'; # Disable: Name "Dancer2::runner" used only once: possible typo
         my $runner_config = defined $Dancer2::runner
                             ? Dancer2->runner->config
                             : {};
+        use warnings 'once';
 
         for my $global ( keys %$runner_config ) {
             next if exists $triggers->{$global};
@@ -107,62 +116,45 @@ sub _build_environment { 'development' }
 sub _build_config_files {
     my ($self) = @_;
 
-    my $location = $self->config_location;
-    # an undef location means no config files for the caller
-    return [] unless defined $location;
-
-    my $running_env = $self->environment;
-    my @available_exts = Config::Any->extensions;
-    my @files;
-
-    my @exts = @available_exts;
-    if (my $ext = $ENV{DANCER_CONFIG_EXT}) {
-        if (grep { $ext eq $_ } @available_exts) {
-            @exts = $ext;
-            warn "Only looking for configs ending in '$ext'\n" 
-                if $ENV{DANCER_CONFIG_VERBOSE};
-        } else {
-            warn "DANCER_CONFIG_EXT environment variable set to '$ext' which\n" .
-                 "is not recognized by Config::Any. Looking for config file\n" .
-                 "using default list of extensions:\n" .
-                 "\t@available_exts\n";
-        }
-    }
-
-    foreach my $file ( [ $location, "config" ],
-        [ $self->environments_location, $running_env ] )
-    {
-        foreach my $ext (@exts) {
-            my $path = path( $file->[0], $file->[1] . ".$ext" );
-            next if !-r $path;
-
-            # Look for *_local.ext files
-            my $local = path( $file->[0], $file->[1] . "_local.$ext" );
-            push @files, $path, ( -r $local ? $local : () );
-        }
-    }
-
-    return \@files;
+    return [ map {
+            warn "Merging config_files from @{[ $_->name() ]}\n" if $ENV{DANCER_CONFIG_VERBOSE};
+            @{ $_->config_files() }
+        } @{ $self->config_readers }
+    ];
 }
 
+# The new config builder
 sub _build_config {
     my ($self) = @_;
 
-    my $location = $self->config_location;
     my $default  = $self->default_config;
-
     my $config = Hash::Merge::Simple->merge(
         $default,
         map {
-            warn "Merging config file $_\n" if $ENV{DANCER_CONFIG_VERBOSE};
-            $self->load_config_file($_) 
-        } @{ $self->config_files }
+            warn "Merging config from @{[ $_->name() ]}\n" if $ENV{DANCER_CONFIG_VERBOSE};
+            $_->read_config()
+        } @{ $self->config_readers }
     );
 
     $config = $self->_normalize_config($config);
     return $config;
 }
 
+sub _build_config_readers {
+    my ($self) = @_;
+
+    my @config_reader_names = $ENV{'DANCER_CONFIG_READERS'}
+                            ? (split qr{ [[:space:]]{1,} }msx, $ENV{'DANCER_CONFIG_READERS'})
+                            : ( q{Dancer2::ConfigReader::File::Simple} );
+
+    return [ map {
+        use_module($_)->new(
+            location => $self->location,
+            environment => $self->environment,
+            );
+    } @config_reader_names ];
+}
+
 sub _set_config_entries {
     my ( $self, @args ) = @_;
     my $no = scalar @args;
@@ -217,24 +209,6 @@ sub has_setting {
     return exists $self->config->{$name};
 }
 
-sub load_config_file {
-    my ( $self, $file ) = @_;
-    my $config;
-
-    eval {
-        my @files = ($file);
-        my $tmpconfig =
-          Config::Any->load_files( { files => \@files, use_ext => 1 } )->[0];
-        ( $file, $config ) = %{$tmpconfig} if defined $tmpconfig;
-    };
-    if ( my $err = $@ || ( !$config ) ) {
-        croak "Unable to parse the configuration file: $file: $@";
-    }
-
-    # TODO handle mergeable entries
-    return $config;
-}
-
 # private
 
 my $_normalizers = {
@@ -281,8 +255,46 @@ __END__
 
 =head1 DESCRIPTION
 
-Provides a C<config> attribute that feeds itself by finding and parsing
-configuration files.
+This is the redesigned C<Dancer2::Core::Role::ConfigReader>
+to manage the Dancer2 configuration.
+
+It is now possible for user to control which B<ConfigReader>
+class to use to create the config.
+
+Use C<DANCER_CONFIG_READERS> environment variable to define
+which class or classes you want.
+
+    DANCER_CONFIG_READERS='Dancer2::ConfigReader::File::Simple Dancer2::ConfigReader::CustomConfig'
+
+If you want several, separate them with whitespace.
+Configs are read in left-to-write order where the previous
+config items get overwritten by subsequent ones.
+
+You can create your own custom B<ConfigReader>.
+The default is to use C<Dancer2::ConfigReader::File::Simple>
+which was the only way to read config files earlier.
+
+If you want, you can also extend class C<Dancer2::ConfigReader::File::Simple>.
+Here is an example:
+
+    package Dancer2::ConfigReader::FileExtended;
+    use Moo;
+    extends 'Dancer2::ConfigReader::File::Simple';
+    has name => (
+        is      => 'ro',
+        default => sub {'FileExtended'},
+    );
+    around read_config => sub {
+        my ($orig, $self) = @_;
+        my $config = $orig->($self, @_);
+        $config->{'dummy'}->{'item'} = 123;
+        return $config;
+    };
+
+
+Provides a C<config> attribute that - when accessing
+the first time - feeds itself by executing one or more
+B<ConfigReader> packages.
 
 Also provides a C<setting()> method which is supposed to be used by externals to
 read/write config entries.
@@ -299,19 +311,20 @@ Gets the location from the configuration. Same as C<< $object->location >>.
 
 =attr environments_location
 
-Gets the directory were the environment files are stored.
+Gets the directory where the environment files are stored.
 
 =attr config
 
 Returns the whole configuration.
 
-=attr environments
+=attr environment
 
 Returns the name of the environment.
 
 =attr config_files
 
-List of all the configuration files.
+List of all the configuration files. This information
+is queried from the B<ConfigReader> classes.
 
 =head1 METHODS
 
@@ -326,7 +339,3 @@ Get or set an element from the configuration.
 =head2 has_setting
 
 Verifies that a key exists in the configuration.
-
-=head2 load_config_file
-
-Load the configuration files.

From d1c4b0af82964ebd8ae4fa6a7f1aa1216b3fe093 Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Wed, 2 Feb 2022 21:43:14 +0100
Subject: [PATCH 03/23] Create ConfigReader role and an implementation

Create Dancer2::Core::Role::ConfigReader and Dancer2::ConfigReader::File::Simple.

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 lib/Dancer2/ConfigReader/File/Simple.pm | 147 ++++++++++++++++++++++++
 lib/Dancer2/Core/Role/ConfigReader.pm   | 125 ++++++++++++++++++++
 2 files changed, 272 insertions(+)
 create mode 100644 lib/Dancer2/ConfigReader/File/Simple.pm
 create mode 100644 lib/Dancer2/Core/Role/ConfigReader.pm

diff --git a/lib/Dancer2/ConfigReader/File/Simple.pm b/lib/Dancer2/ConfigReader/File/Simple.pm
new file mode 100644
index 000000000..f4353980f
--- /dev/null
+++ b/lib/Dancer2/ConfigReader/File/Simple.pm
@@ -0,0 +1,147 @@
+package Dancer2::ConfigReader::File::Simple;
+
+use Moo;
+
+use File::Spec;
+use Config::Any;
+use Hash::Merge::Simple;
+use Carp 'croak';
+use Module::Runtime 'require_module';
+
+use Dancer2::Core::Factory;
+use Dancer2::Core;
+use Dancer2::Core::Types;
+use Dancer2::FileUtils 'path';
+
+with 'Dancer2::Core::Role::ConfigReader';
+
+has name => (
+    is      => 'ro',
+    isa     => Str,
+    lazy    => 0,
+    default => sub {'File::Simple'},
+);
+
+has config_files => (
+    is      => 'ro',
+    lazy    => 1,
+    isa     => ArrayRef,
+    builder => '_build_config_files',
+);
+
+sub read_config {
+    my ($self) = @_;
+
+    my $config = Hash::Merge::Simple->merge(
+        map {
+            warn "Merging config file $_\n" if $ENV{DANCER_CONFIG_VERBOSE};
+            $self->_load_config_file($_)
+        } @{ $self->config_files }
+    );
+
+    return $config;
+}
+
+sub _build_config_files {
+    my ($self) = @_;
+
+    my $location = $self->config_location;
+    # an undef location means no config files for the caller
+    return [] unless defined $location;
+
+    my $running_env = $self->environment;
+    my @available_exts = Config::Any->extensions;
+    my @files;
+
+    my @exts = @available_exts;
+    if (my $ext = $ENV{DANCER_CONFIG_EXT}) {
+        if (grep { $ext eq $_ } @available_exts) {
+            @exts = $ext;
+            warn "Only looking for configs ending in '$ext'\n"
+                if $ENV{DANCER_CONFIG_VERBOSE};
+        } else {
+            warn "DANCER_CONFIG_EXT environment variable set to '$ext' which\n" .
+                 "is not recognized by Config::Any. Looking for config file\n" .
+                 "using default list of extensions:\n" .
+                 "\t@available_exts\n";
+        }
+    }
+
+    foreach my $file ( [ $location, "config" ],
+        [ $self->environments_location, $running_env ] )
+    {
+        foreach my $ext (@exts) {
+            my $path = path( $file->[0], $file->[1] . ".$ext" );
+            next if !-r $path;
+
+            # Look for *_local.ext files
+            my $local = path( $file->[0], $file->[1] . "_local.$ext" );
+            push @files, $path, ( -r $local ? $local : () );
+        }
+    }
+
+    return \@files;
+}
+
+sub _load_config_file {
+    my ( $self, $file ) = @_;
+    my $config;
+
+    eval {
+        my @files = ($file);
+        my $tmpconfig =
+          Config::Any->load_files( { files => \@files, use_ext => 1 } )->[0];
+        ( $file, $config ) = %{$tmpconfig} if defined $tmpconfig;
+    };
+    if ( my $err = $@ || ( !$config ) ) {
+        croak "Unable to parse the configuration file: $file: $@";
+    }
+
+    # TODO handle mergeable entries
+    return $config;
+}
+
+1;
+
+__END__
+
+=head1 DESCRIPTION
+
+This class provides the same features to read configuration files
+as were earlier done by C<Dancer2::Core::Role::Config>.
+
+If you need to add additional functionality to the reading
+mechanism, you can extend this class. An example of this is
+in: B</t/lib/Dancer2/ConfigReader/File/Extended.pm>
+
+=head1 ATTRIBUTES
+
+=attr name
+
+The name of the class.
+
+=attr location
+
+Absolute path to the directory where the server started.
+
+=attr config_location
+
+Gets the location from the configuration. Same as C<< $object->location >>.
+
+=attr environments_location
+
+Gets the directory where the environment files are stored.
+
+=attr environment
+
+Returns the name of the environment.
+
+=attr config_files
+
+List of all the configuration files.
+
+=head1 METHODS
+
+=head2 read_config
+
+Load the configuration files.
diff --git a/lib/Dancer2/Core/Role/ConfigReader.pm b/lib/Dancer2/Core/Role/ConfigReader.pm
new file mode 100644
index 000000000..b63fe1fa6
--- /dev/null
+++ b/lib/Dancer2/Core/Role/ConfigReader.pm
@@ -0,0 +1,125 @@
+# ABSTRACT: Config reader role for Dancer2 core objects
+package Dancer2::Core::Role::ConfigReader;
+
+use Moo::Role;
+
+use File::Spec;
+use Config::Any;
+use Hash::Merge::Simple;
+use Carp 'croak';
+use Module::Runtime 'require_module';
+
+use Dancer2::Core::Factory;
+use Dancer2::Core;
+use Dancer2::Core::Types;
+use Dancer2::FileUtils 'path';
+
+has config_location => (
+    is      => 'ro',
+    isa     => ReadableFilePath,
+    lazy    => 1,
+    default => sub { $ENV{DANCER_CONFDIR} || $_[0]->location },
+);
+
+# The type for this attribute is Str because we don't require
+# an existing directory with configuration files for the
+# environments.  An application without environments is still
+# valid and works.
+has environments_location => (
+    is      => 'ro',
+    isa     => Str,
+    lazy    => 1,
+    default => sub {
+        $ENV{DANCER_ENVDIR}
+          || File::Spec->catdir( $_[0]->config_location, 'environments' )
+          || File::Spec->catdir( $_[0]->location,        'environments' );
+    },
+);
+
+# It is required to get environment from the caller.
+# Environment should be passed down from Dancer2::Core::App.
+has environment => (
+    is       => 'ro',
+    isa      => Str,
+    required => 1,
+);
+
+# It is required to get location from the caller.
+has location => (
+    is       => 'ro',
+    isa      => ReadableFilePath,
+    required => 1,
+);
+
+1;
+
+__END__
+
+=head1 DESCRIPTION
+
+This role is implemented by different
+config readers. A config reader creates the
+configuration for Dancer2 app.
+Config can be created by reading configuration
+files, from environment variables, by fetching
+it from a cloud service, or any other means.
+
+By default, the config loader
+which is used, is C<Dancer2::ConfigReader::File::Simple>
+but user can create his own config reader
+if he wants to replace or augment
+the default method of config creation.
+That method should implement this role.
+
+The implementing module gets the following parameters
+during creation:
+
+=attr environment
+
+The name of the environment used, e.g.
+production, development, staging.
+
+==attr location
+
+Absolute path to the directory where the server started.
+
+These arguments are passed when the object is created by
+C<Dancer2::Core::Role::Config>. How the config
+reader applies them as it needs.
+
+Provides a C<config> attribute that - when accessing
+the first time - feeds itself by finding and parsing
+configuration files.
+
+Also provides a C<setting()> method which is
+supposed to be used by externals to
+read/write config entries.
+
+=head1 ATTRIBUTES
+
+=attr location
+
+Absolute path to the directory where the server started.
+
+=attr config_location
+
+Gets the location from the configuration. Same as C<< $object->location >>.
+
+=attr environments_location
+
+Gets the directory where the environment files are stored.
+
+=attr config
+
+Returns the whole configuration.
+
+=attr environments
+
+Returns the name of the environment.
+
+=head1 METHODS
+
+=head2 read_config
+
+Load the configuration.
+Whatever source the config comes from, files, env vars, etc.

From 13640fad311007b3b152e27e4f92e6b94d43ee4a Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Wed, 2 Feb 2022 21:46:33 +0100
Subject: [PATCH 04/23] Add tests for new ConfigReader

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 t/app/t_config_file_extended/bin/app.psgi   |  6 ++
 t/app/t_config_file_extended/config.yml     |  5 ++
 t/app/t_config_file_extended/lib/App1.pm    |  6 ++
 t/config_file_extended.t                    | 34 +++++++++++
 t/config_many.t                             | 30 ++++++++++
 t/{config_reader.t => config_role.t}        | 16 ++---
 t/lib/Dancer2/ConfigReader/File/Extended.pm | 66 +++++++++++++++++++++
 t/lib/Dancer2/ConfigReader/TestDummy.pm     | 36 +++++++++++
 8 files changed, 191 insertions(+), 8 deletions(-)
 create mode 100644 t/app/t_config_file_extended/bin/app.psgi
 create mode 100644 t/app/t_config_file_extended/config.yml
 create mode 100644 t/app/t_config_file_extended/lib/App1.pm
 create mode 100644 t/config_file_extended.t
 create mode 100644 t/config_many.t
 rename t/{config_reader.t => config_role.t} (91%)
 create mode 100644 t/lib/Dancer2/ConfigReader/File/Extended.pm
 create mode 100644 t/lib/Dancer2/ConfigReader/TestDummy.pm

diff --git a/t/app/t_config_file_extended/bin/app.psgi b/t/app/t_config_file_extended/bin/app.psgi
new file mode 100644
index 000000000..ef8335285
--- /dev/null
+++ b/t/app/t_config_file_extended/bin/app.psgi
@@ -0,0 +1,6 @@
+#!perl
+
+use Dancer2;
+use App1;
+
+start;
diff --git a/t/app/t_config_file_extended/config.yml b/t/app/t_config_file_extended/config.yml
new file mode 100644
index 000000000..e839c49f2
--- /dev/null
+++ b/t/app/t_config_file_extended/config.yml
@@ -0,0 +1,5 @@
+app:
+    config: ok
+extended:
+    one: ${ENV:DANCER_FILE_EXTENDED_ONE}
+    two: Begin ${ENV:DANCER_FILE_EXTENDED_TWO} End
diff --git a/t/app/t_config_file_extended/lib/App1.pm b/t/app/t_config_file_extended/lib/App1.pm
new file mode 100644
index 000000000..62a86f3c6
--- /dev/null
+++ b/t/app/t_config_file_extended/lib/App1.pm
@@ -0,0 +1,6 @@
+package App1;
+use strict;
+use warnings;
+use Dancer2;
+
+1;
diff --git a/t/config_file_extended.t b/t/config_file_extended.t
new file mode 100644
index 000000000..b40946b97
--- /dev/null
+++ b/t/config_file_extended.t
@@ -0,0 +1,34 @@
+use strict;
+use warnings;
+
+use Test::More;
+use File::Spec;
+
+BEGIN {
+    # undefine ENV vars used as defaults for app environment in these tests
+    local $ENV{DANCER_ENVIRONMENT};
+    local $ENV{PLACK_ENV};
+    $ENV{DANCER_CONFIG_READERS} = 'Dancer2::ConfigReader::File::Extended';
+    $ENV{DANCER_FILE_EXTENDED_ONE} = 'Extended String';
+    $ENV{DANCER_FILE_EXTENDED_TWO} = 'ExtendedToo';
+}
+use lib '.';
+use lib './t/lib';
+
+use t::app::t_config_file_extended::lib::App1;
+
+my $app = Dancer2->runner->apps->[0];
+
+is_deeply $app->config_files,
+    [ File::Spec->rel2abs(File::Spec->catfile( 't', 'app',
+                't_config_file_extended', 'config.yml' )) ],
+    $app->name . ": config files found";
+
+is $app->config->{app}->{config}, 'ok',
+    $app->name . ": config loaded properly";
+is $app->config->{extended}->{one}, 'Extended String',
+    $app->name . ": extended config (extended:one) loaded properly";
+is $app->config->{extended}->{two}, 'Begin ExtendedToo End',
+    $app->name . ": extended config (extended:two) loaded properly";
+
+done_testing;
diff --git a/t/config_many.t b/t/config_many.t
new file mode 100644
index 000000000..4755560db
--- /dev/null
+++ b/t/config_many.t
@@ -0,0 +1,30 @@
+use strict;
+use warnings;
+
+use Test::More;
+use File::Spec;
+
+BEGIN {
+    # undefine ENV vars used as defaults for app environment in these tests
+    local $ENV{DANCER_ENVIRONMENT};
+    local $ENV{PLACK_ENV};
+    $ENV{DANCER_CONFIG_READERS}
+        = 'Dancer2::ConfigReader::File::Simple Dancer2::ConfigReader::TestDummy';
+}
+use lib '.';
+use lib './t/lib';
+
+use t::app::t1::lib::App1;
+
+my $app = Dancer2->runner->apps->[0];
+
+is_deeply $app->config_files,
+    [ File::Spec->rel2abs(File::Spec->catfile( 't', 'app', 't1', 'config.yml' )) ],
+    $app->name . ": config files found";
+
+is $app->config->{app}->{config}, 'ok',
+    $app->name . ": config loaded properly";
+is $app->config->{dummy}->{dummy_subitem}, 2,
+    $app->name . ": dummy config loaded properly";
+
+done_testing;
diff --git a/t/config_reader.t b/t/config_role.t
similarity index 91%
rename from t/config_reader.t
rename to t/config_role.t
index 3426ba73c..bb8893382 100644
--- a/t/config_reader.t
+++ b/t/config_role.t
@@ -21,7 +21,7 @@ my $location2 = File::Spec->rel2abs( path( dirname(__FILE__), 'config2' ) );
 
     package Prod;
     use Moo;
-    with 'Dancer2::Core::Role::ConfigReader';
+    with 'Dancer2::Core::Role::Config';
 
     sub name {'Prod'}
 
@@ -31,7 +31,7 @@ my $location2 = File::Spec->rel2abs( path( dirname(__FILE__), 'config2' ) );
 
     package Dev;
     use Moo;
-    with 'Dancer2::Core::Role::ConfigReader';
+    with 'Dancer2::Core::Role::Config';
 
     sub _build_environment    {'development'}
     sub _build_location       {$location};
@@ -39,7 +39,7 @@ my $location2 = File::Spec->rel2abs( path( dirname(__FILE__), 'config2' ) );
 
     package Failure;
     use Moo;
-    with 'Dancer2::Core::Role::ConfigReader';
+    with 'Dancer2::Core::Role::Config';
 
     sub _build_environment    {'failure'}
     sub _build_location       {$location}
@@ -47,7 +47,7 @@ my $location2 = File::Spec->rel2abs( path( dirname(__FILE__), 'config2' ) );
 
     package Staging;
     use Moo;
-    with 'Dancer2::Core::Role::ConfigReader';
+    with 'Dancer2::Core::Role::Config';
 
     sub _build_environment    {'staging'}
     sub _build_location       {$location}
@@ -55,7 +55,7 @@ my $location2 = File::Spec->rel2abs( path( dirname(__FILE__), 'config2' ) );
 
     package Merging;
     use Moo;
-    with 'Dancer2::Core::Role::ConfigReader';
+    with 'Dancer2::Core::Role::Config';
 
     sub name {'Merging'}
 
@@ -65,7 +65,7 @@ my $location2 = File::Spec->rel2abs( path( dirname(__FILE__), 'config2' ) );
 
     package LocalConfig;
     use Moo;
-    with 'Dancer2::Core::Role::ConfigReader';
+    with 'Dancer2::Core::Role::Config';
 
     sub name {'LocalConfig'}
 
@@ -81,8 +81,8 @@ is_deeply $d->config_files,
   "config_files() only sees existing files";
 
 my $f = Prod->new;
-is $f->does('Dancer2::Core::Role::ConfigReader'), 1,
-  "role Dancer2::Core::Role::ConfigReader is consumed";
+is $f->does('Dancer2::Core::Role::Config'), 1,
+  "role Dancer2::Core::Role::Config is consumed";
 
 is_deeply $f->config_files,
   [ path( $location, 'config.yml' ),
diff --git a/t/lib/Dancer2/ConfigReader/File/Extended.pm b/t/lib/Dancer2/ConfigReader/File/Extended.pm
new file mode 100644
index 000000000..d6764763e
--- /dev/null
+++ b/t/lib/Dancer2/ConfigReader/File/Extended.pm
@@ -0,0 +1,66 @@
+package Dancer2::ConfigReader::File::Extended;
+
+use Moo;
+use Dancer2::Core::Types;
+
+use Carp 'croak';
+
+extends 'Dancer2::ConfigReader::File::Simple';
+
+has name => (
+    is      => 'ro',
+    isa     => Str,
+    lazy    => 0,
+    default => sub {'File::Extended'},
+);
+
+around read_config => sub {
+    my ($orig, $self) = @_;
+    my $config = $orig->($self, @_);
+    $self->_replace_env_vars($config);
+    return $config;
+};
+
+# Attn. We are traversing along the original data structure all the time,
+# using references, and changing values on the spot, not returning anything.
+sub _replace_env_vars {
+    my ( $self, $entry ) = @_;
+    if( ref $entry ne 'HASH' && ref $entry ne 'ARRAY' ) {
+        croak 'Param entry is not HASH or ARRAY';
+    }
+    if( ref $entry eq 'HASH' ) {
+        foreach my $value (values %{ $entry }) {
+            if( (ref $value) =~ m/(HASH|ARRAY)/msx ) {
+                    $self->_replace_env_vars( $value );
+                } elsif( (ref $value) =~ m/(CODE|REF|GLOB)/msx ) {
+                    # Pretty much anything else except SCALAR. Do nothing
+                    1;
+                } else {
+                    if( $value ) {
+                        while( my ($k, $v) = each %ENV) {
+                            $value =~ s/ \$ [{] ENV:$k [}] /$v/gmsx;
+                        }
+                    }
+                }
+            }
+        } else {
+            # ref $entry is 'ARRAY'
+            foreach my $value (@{ $entry }) {
+                if( (ref $value) =~ m/(HASH|ARRAY)/msx ) {
+                        $self->_replace_env_vars( $value );
+                } elsif( (ref $value) =~ m/(CODE|REF|GLOB)/msx ) {
+                    # Pretty much anything else except SCALAR. Do nothing
+                    1;
+                } else {
+                    if( $value ) {
+                        while( my ($k, $v) = each %ENV) {
+                            $value =~ s/ \$ [{] ENV:$k [}] /$v/gmsx;
+                        }
+                    }
+                }
+            }
+        }
+    return;
+}
+
+1;
diff --git a/t/lib/Dancer2/ConfigReader/TestDummy.pm b/t/lib/Dancer2/ConfigReader/TestDummy.pm
new file mode 100644
index 000000000..042a8ce6d
--- /dev/null
+++ b/t/lib/Dancer2/ConfigReader/TestDummy.pm
@@ -0,0 +1,36 @@
+package Dancer2::ConfigReader::TestDummy;
+use Moo;
+use Dancer2::Core::Factory;
+use Dancer2::Core;
+use Dancer2::Core::Types;
+use Dancer2::FileUtils 'path';
+
+with 'Dancer2::Core::Role::ConfigReader';
+
+has name => (
+    is      => 'ro',
+    isa     => Str,
+    lazy    => 0,
+    default => sub {'TestDummy'},
+);
+
+has config_files => (
+    is      => 'ro',
+    lazy    => 1,
+    isa     => ArrayRef,
+    default => sub {
+        my ($self) = @_;
+        return [];
+    },
+);
+
+sub read_config {
+    my %config = (
+        dummy => {
+            dummy_subitem => 2,
+        }
+    );
+    return \%config;
+}
+
+1;

From 25970ab0a521c47f2f5e84567fd9d6808ea3d5d3 Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Sun, 27 Mar 2022 14:17:12 +0200
Subject: [PATCH 05/23] Change regex: remove POSIX form

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 lib/Dancer2/Core/Role/Config.pm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/Dancer2/Core/Role/Config.pm b/lib/Dancer2/Core/Role/Config.pm
index fec20ec01..5eedf8fc9 100644
--- a/lib/Dancer2/Core/Role/Config.pm
+++ b/lib/Dancer2/Core/Role/Config.pm
@@ -144,7 +144,7 @@ sub _build_config_readers {
     my ($self) = @_;
 
     my @config_reader_names = $ENV{'DANCER_CONFIG_READERS'}
-                            ? (split qr{ [[:space:]]{1,} }msx, $ENV{'DANCER_CONFIG_READERS'})
+                            ? (split qr{ \s+ }msx, $ENV{'DANCER_CONFIG_READERS'})
                             : ( q{Dancer2::ConfigReader::File::Simple} );
 
     return [ map {

From 7c395437ee971b551ebc157efbcc17cf3effa494 Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Sun, 27 Mar 2022 14:22:27 +0200
Subject: [PATCH 06/23] Reformat

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 lib/Dancer2/Core/Role/Config.pm | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/lib/Dancer2/Core/Role/Config.pm b/lib/Dancer2/Core/Role/Config.pm
index 5eedf8fc9..6b3e58534 100644
--- a/lib/Dancer2/Core/Role/Config.pm
+++ b/lib/Dancer2/Core/Role/Config.pm
@@ -147,12 +147,12 @@ sub _build_config_readers {
                             ? (split qr{ \s+ }msx, $ENV{'DANCER_CONFIG_READERS'})
                             : ( q{Dancer2::ConfigReader::File::Simple} );
 
-    return [ map {
-        use_module($_)->new(
-            location => $self->location,
+    return [
+        map use_module($_)->new(
+            location    => $self->location,
             environment => $self->environment,
-            );
-    } @config_reader_names ];
+        ), @config_reader_names
+    ];
 }
 
 sub _set_config_entries {

From 9465fdcc71feebcd257da48dd6221da53629f20d Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Sun, 27 Mar 2022 14:24:39 +0200
Subject: [PATCH 07/23] Reformat: no warnings 'once'

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 lib/Dancer2/Core/Role/Config.pm | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/lib/Dancer2/Core/Role/Config.pm b/lib/Dancer2/Core/Role/Config.pm
index 6b3e58534..ecf2eec66 100644
--- a/lib/Dancer2/Core/Role/Config.pm
+++ b/lib/Dancer2/Core/Role/Config.pm
@@ -91,11 +91,13 @@ has global_triggers => (
             },
         };
 
-        no warnings 'once'; # Disable: Name "Dancer2::runner" used only once: possible typo
-        my $runner_config = defined $Dancer2::runner
-                            ? Dancer2->runner->config
-                            : {};
-        use warnings 'once';
+        my $runner_config;
+        {
+            no warnings 'once';
+            $runner_config = defined $Dancer2::runner
+                           ? Dancer2->runner->config
+                           : {};
+        }
 
         for my $global ( keys %$runner_config ) {
             next if exists $triggers->{$global};

From dafd2ce5ba560c196079ebba31b376741a2aac0f Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Sun, 27 Mar 2022 14:39:33 +0200
Subject: [PATCH 08/23] Rework POD and add an example how to extend

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 lib/Dancer2/ConfigReader/File/Simple.pm | 76 ++++++++++++++++++++++++-
 1 file changed, 74 insertions(+), 2 deletions(-)

diff --git a/lib/Dancer2/ConfigReader/File/Simple.pm b/lib/Dancer2/ConfigReader/File/Simple.pm
index f4353980f..e5b42a07d 100644
--- a/lib/Dancer2/ConfigReader/File/Simple.pm
+++ b/lib/Dancer2/ConfigReader/File/Simple.pm
@@ -107,13 +107,85 @@ __END__
 
 =head1 DESCRIPTION
 
-This class provides the same features to read configuration files
-as were earlier done by C<Dancer2::Core::Role::Config>.
+This class is an implementation of C<Dancer2::Core::Role::ConfigReader>.
+It reads the configuration files of C<Dancer2>.
+
+Please see C<Dancer2::Config> for more information.
 
 If you need to add additional functionality to the reading
 mechanism, you can extend this class. An example of this is
 in: B</t/lib/Dancer2/ConfigReader/File/Extended.pm>
 
+An example of this is providing the possibility to replace
+random parts of the file config with environmental variables:
+
+    package Dancer2::ConfigReader::File::Extended;
+
+    use Moo;
+    use Dancer2::Core::Types;
+
+    use Carp 'croak';
+
+    extends 'Dancer2::ConfigReader::File::Simple';
+
+    has name => (
+        is      => 'ro',
+        isa     => Str,
+        lazy    => 0,
+        default => sub {'File::Extended'},
+    );
+
+    around read_config => sub {
+        my ($orig, $self) = @_;
+        my $config = $orig->($self, @_);
+        $self->_replace_env_vars($config);
+        return $config;
+    };
+
+    # Attn. We are traversing along the original data structure all the time,
+    # using references, and changing values on the spot, not returning anything.
+    sub _replace_env_vars {
+        my ( $self, $entry ) = @_;
+        if( ref $entry ne 'HASH' && ref $entry ne 'ARRAY' ) {
+            croak 'Param entry is not HASH or ARRAY';
+        }
+        if( ref $entry eq 'HASH' ) {
+            foreach my $value (values %{ $entry }) {
+                if( (ref $value) =~ m/(HASH|ARRAY)/msx ) {
+                        $self->_replace_env_vars( $value );
+                    } elsif( (ref $value) =~ m/(CODE|REF|GLOB)/msx ) {
+                        # Pretty much anything else except SCALAR. Do nothing
+                        1;
+                    } else {
+                        if( $value ) {
+                            while( my ($k, $v) = each %ENV) {
+                                $value =~ s/ \$ [{] ENV:$k [}] /$v/gmsx;
+                            }
+                        }
+                    }
+                }
+            } else {
+                # ref $entry is 'ARRAY'
+                foreach my $value (@{ $entry }) {
+                    if( (ref $value) =~ m/(HASH|ARRAY)/msx ) {
+                            $self->_replace_env_vars( $value );
+                    } elsif( (ref $value) =~ m/(CODE|REF|GLOB)/msx ) {
+                        # Pretty much anything else except SCALAR. Do nothing
+                        1;
+                    } else {
+                        if( $value ) {
+                            while( my ($k, $v) = each %ENV) {
+                                $value =~ s/ \$ [{] ENV:$k [}] /$v/gmsx;
+                            }
+                        }
+                    }
+                }
+            }
+        return;
+    }
+
+    1;
+
 =head1 ATTRIBUTES
 
 =attr name

From b319d6cb84582d44a9e2b983001b688ab8c7ddf8 Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Sun, 27 Mar 2022 15:16:15 +0200
Subject: [PATCH 09/23] Rewrite documentation of Dancer2::Core::Role::Config

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 lib/Dancer2/Core/Role/Config.pm | 68 +++++++++++++++++++++++++--------
 1 file changed, 53 insertions(+), 15 deletions(-)

diff --git a/lib/Dancer2/Core/Role/Config.pm b/lib/Dancer2/Core/Role/Config.pm
index ecf2eec66..79cb651a1 100644
--- a/lib/Dancer2/Core/Role/Config.pm
+++ b/lib/Dancer2/Core/Role/Config.pm
@@ -257,11 +257,15 @@ __END__
 
 =head1 DESCRIPTION
 
-This is the redesigned C<Dancer2::Core::Role::ConfigReader>
-to manage the Dancer2 configuration.
+This class provides a C<config> attribute that - when accessing
+the first time - feeds itself by executing one or more
+B<ConfigReader> packages.
+
+Also provides a C<setting()> method which is supposed to be used by externals to
+read/write config entries.
 
-It is now possible for user to control which B<ConfigReader>
-class to use to create the config.
+You can control which B<ConfigReader>
+class or classes to use to create the config.
 
 Use C<DANCER_CONFIG_READERS> environment variable to define
 which class or classes you want.
@@ -269,12 +273,52 @@ which class or classes you want.
     DANCER_CONFIG_READERS='Dancer2::ConfigReader::File::Simple Dancer2::ConfigReader::CustomConfig'
 
 If you want several, separate them with whitespace.
-Configs are read in left-to-write order where the previous
+Configs are added in left-to-write order where the previous
 config items get overwritten by subsequent ones.
 
-You can create your own custom B<ConfigReader>.
-The default is to use C<Dancer2::ConfigReader::File::Simple>
-which was the only way to read config files earlier.
+For example, if config
+
+    item1: content1
+    item2: content2
+    item3:
+        subitem1: subcontent1
+        subitem2: subcontent2
+        subitem3:
+            subsubitem1:
+                subsubcontent1
+    item4:
+        subitem1: subcontent1
+        subitem2: subcontent2
+
+was followed by config
+
+    item2: content9
+    item3:
+        subitem2: subcontent8
+        subitem3:
+            subsubitem1:
+                subsubcontent7
+        subitem4:
+            subsubitem5: subsubcontent5
+    item4: content4
+
+then the final config would be
+
+    item1: content1
+    item2: content9
+    item3:
+        subitem1: subcontent1
+        subitem2: subcontent8
+        subitem3:
+            subsubitem1:
+                subsubcontent7
+        subitem4:
+            subsubitem5: subsubcontent5
+    item4: content4
+
+The default B<ConfigReader> is C<Dancer2::ConfigReader::File::Simple>.
+
+You can also create your own custom B<ConfigReader> classes.
 
 If you want, you can also extend class C<Dancer2::ConfigReader::File::Simple>.
 Here is an example:
@@ -293,13 +337,7 @@ Here is an example:
         return $config;
     };
 
-
-Provides a C<config> attribute that - when accessing
-the first time - feeds itself by executing one or more
-B<ConfigReader> packages.
-
-Also provides a C<setting()> method which is supposed to be used by externals to
-read/write config entries.
+Another (more complex) example is in the file C<Dancer2::ConfigReader::File::Simple>.
 
 =head1 ATTRIBUTES
 

From adb4cd202933a29f1a68d348774c96f57b5d6bee Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Sun, 27 Mar 2022 15:49:44 +0200
Subject: [PATCH 10/23] Add ABSTRACT to ConfigReader::File::Simple

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 lib/Dancer2/ConfigReader/File/Simple.pm | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/Dancer2/ConfigReader/File/Simple.pm b/lib/Dancer2/ConfigReader/File/Simple.pm
index e5b42a07d..85df8f420 100644
--- a/lib/Dancer2/ConfigReader/File/Simple.pm
+++ b/lib/Dancer2/ConfigReader/File/Simple.pm
@@ -1,3 +1,4 @@
+# ABSTRACT: Config reader for files
 package Dancer2::ConfigReader::File::Simple;
 
 use Moo;

From 622336cb1f16d95c56995e4c1b726d2d112486e0 Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Sun, 27 Mar 2022 16:22:14 +0200
Subject: [PATCH 11/23] Remove attr config_files from
 Dancer2::Core::Role::Config

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 lib/Dancer2/Core/App.pm         |  2 --
 lib/Dancer2/Core/Role/Config.pm | 22 ----------------------
 t/config-files-logged.t         | 17 -----------------
 t/config_file_extended.t        |  5 -----
 t/config_many.t                 |  4 ----
 t/config_multiapp.t             |  4 ----
 t/config_role.t                 | 30 ------------------------------
 7 files changed, 84 deletions(-)
 delete mode 100644 t/config-files-logged.t

diff --git a/lib/Dancer2/Core/App.pm b/lib/Dancer2/Core/App.pm
index 3413552e7..c9d0a49fb 100644
--- a/lib/Dancer2/Core/App.pm
+++ b/lib/Dancer2/Core/App.pm
@@ -1109,8 +1109,6 @@ sub BUILD {
     my $self = shift;
     $self->init_route_handlers();
     $self->_init_hooks();
-
-    $self->log(core => 'Built config from files: ' . join(' ', @{$self->config_files}));
 }
 
 sub finish {
diff --git a/lib/Dancer2/Core/Role/Config.pm b/lib/Dancer2/Core/Role/Config.pm
index 79cb651a1..ca83bdf2a 100644
--- a/lib/Dancer2/Core/Role/Config.pm
+++ b/lib/Dancer2/Core/Role/Config.pm
@@ -59,13 +59,6 @@ has environment => (
     builder => '_build_environment',
 );
 
-has config_files => (
-    is      => 'ro',
-    lazy    => 1,
-    isa     => ArrayRef,
-    builder => '_build_config_files',
-);
-
 has config_readers => (
     is      => 'ro',
     lazy    => 1,
@@ -115,16 +108,6 @@ sub _build_default_config { +{} }
 
 sub _build_environment { 'development' }
 
-sub _build_config_files {
-    my ($self) = @_;
-
-    return [ map {
-            warn "Merging config_files from @{[ $_->name() ]}\n" if $ENV{DANCER_CONFIG_VERBOSE};
-            @{ $_->config_files() }
-        } @{ $self->config_readers }
-    ];
-}
-
 # The new config builder
 sub _build_config {
     my ($self) = @_;
@@ -361,11 +344,6 @@ Returns the whole configuration.
 
 Returns the name of the environment.
 
-=attr config_files
-
-List of all the configuration files. This information
-is queried from the B<ConfigReader> classes.
-
 =head1 METHODS
 
 =head2 settings
diff --git a/t/config-files-logged.t b/t/config-files-logged.t
deleted file mode 100644
index aac1d7822..000000000
--- a/t/config-files-logged.t
+++ /dev/null
@@ -1,17 +0,0 @@
-use strict;
-use warnings;
-
-use Test::More;
-use File::Spec;
-
-use lib '.';
-use t::app::t3::lib::App4;
-
-my ($app) = @{ Dancer2->runner->apps };
-my $trap = $app->logger_engine->trapper;
-my $logs = $trap->read;
-
-like( $logs->[0]{message}, qr/Built config from files/, 'log message ok');
-
-done_testing;
-
diff --git a/t/config_file_extended.t b/t/config_file_extended.t
index b40946b97..fc4b3323c 100644
--- a/t/config_file_extended.t
+++ b/t/config_file_extended.t
@@ -19,11 +19,6 @@ use t::app::t_config_file_extended::lib::App1;
 
 my $app = Dancer2->runner->apps->[0];
 
-is_deeply $app->config_files,
-    [ File::Spec->rel2abs(File::Spec->catfile( 't', 'app',
-                't_config_file_extended', 'config.yml' )) ],
-    $app->name . ": config files found";
-
 is $app->config->{app}->{config}, 'ok',
     $app->name . ": config loaded properly";
 is $app->config->{extended}->{one}, 'Extended String',
diff --git a/t/config_many.t b/t/config_many.t
index 4755560db..ab28a66d0 100644
--- a/t/config_many.t
+++ b/t/config_many.t
@@ -18,10 +18,6 @@ use t::app::t1::lib::App1;
 
 my $app = Dancer2->runner->apps->[0];
 
-is_deeply $app->config_files,
-    [ File::Spec->rel2abs(File::Spec->catfile( 't', 'app', 't1', 'config.yml' )) ],
-    $app->name . ": config files found";
-
 is $app->config->{app}->{config}, 'ok',
     $app->name . ": config loaded properly";
 is $app->config->{dummy}->{dummy_subitem}, 2,
diff --git a/t/config_multiapp.t b/t/config_multiapp.t
index a2acc6c48..e54eb4426 100644
--- a/t/config_multiapp.t
+++ b/t/config_multiapp.t
@@ -13,10 +13,6 @@ for my $app ( @{ Dancer2->runner->apps } ) {
     # Need to determine path to config; use apps' name for now..
     my $path = $app->name eq 'App3' ? 't2' : 't1';
 
-    is_deeply $app->config_files,
-        [ File::Spec->rel2abs(File::Spec->catfile( 't', 'app', $path, 'config.yml' )) ],
-        $app->name . ": config files found";
-
     is $app->config->{app}->{config}, 'ok',
         $app->name . ": config loaded properly"
 }
diff --git a/t/config_role.t b/t/config_role.t
index bb8893382..97e060c9f 100644
--- a/t/config_role.t
+++ b/t/config_role.t
@@ -76,37 +76,15 @@ my $location2 = File::Spec->rel2abs( path( dirname(__FILE__), 'config2' ) );
 }
 
 my $d = Dev->new();
-is_deeply $d->config_files,
-  [ path( $location, 'config.yml' ), ],
-  "config_files() only sees existing files";
 
 my $f = Prod->new;
 is $f->does('Dancer2::Core::Role::Config'), 1,
   "role Dancer2::Core::Role::Config is consumed";
 
-is_deeply $f->config_files,
-  [ path( $location, 'config.yml' ),
-    path( $location, 'environments', 'production.yml' ),
-  ],
-  "config_files() works";
-
-my $j = Staging->new;
-is_deeply $j->config_files,
-  [ path( $location, 'config.yml' ),
-    path( $location, 'environments', 'staging.json' ),
-  ],
-  "config_files() does JSON too!";
-
 note "bad YAML file";
 my $fail = Failure->new;
 is $fail->environment, 'failure';
 
-is_deeply $fail->config_files,
-  [ path( $location, 'config.yml' ),
-    path( $location, 'environments', 'failure.yml' ),
-  ],
-  "config_files() works";
-
 like(
     exception { $fail->config },
     qr{Unable to parse the configuration file}, 'Configuration file parsing failure',
@@ -126,14 +104,6 @@ is_deeply $m->config->{application},
 {
     my $l = LocalConfig->new;
 
-    is_deeply $l->config_files,
-      [ path( $location2, 'config.yml' ),
-        path( $location2, 'config_local.yml' ),
-        path( $location2, 'environments', 'lconfig.yml' ),
-        path( $location2, 'environments', 'lconfig_local.yml' ),
-      ],
-      "config_files() with local config works";
-
     is_deeply $l->config->{application},
       { feature_1 => 'foo',
         feature_2 => 'alpha',

From 8827022b10d464f4864cbdee6ae1f2dd63f7a221 Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Sun, 8 May 2022 20:16:35 +0200
Subject: [PATCH 12/23] Create Role::HasEnvironment and tests

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 lib/Dancer2/Core/Role/HasEnvironment.pm       | 21 +++++++
 .../Dancer2-Core-Role-HasEnvironment/with.t   | 63 +++++++++++++++++++
 2 files changed, 84 insertions(+)
 create mode 100644 lib/Dancer2/Core/Role/HasEnvironment.pm
 create mode 100644 t/classes/Dancer2-Core-Role-HasEnvironment/with.t

diff --git a/lib/Dancer2/Core/Role/HasEnvironment.pm b/lib/Dancer2/Core/Role/HasEnvironment.pm
new file mode 100644
index 000000000..631dd7264
--- /dev/null
+++ b/lib/Dancer2/Core/Role/HasEnvironment.pm
@@ -0,0 +1,21 @@
+# ABSTRACT: Role for application environment name
+package Dancer2::Core::Role::HasEnvironment;
+
+use Moo::Role;
+use Dancer2::Core::Types;
+
+my $DEFAULT_ENVIRONMENT = q{development};
+
+has environment => (
+    is      => 'ro',
+    isa     => Str,
+    lazy    => 1,
+    builder => '_build_environment',
+);
+
+sub _build_environment {
+    my ($self) = @_;
+    return $ENV{DANCER_ENVIRONMENT} || $ENV{PLACK_ENV} || $DEFAULT_ENVIRONMENT;
+}
+
+1;
diff --git a/t/classes/Dancer2-Core-Role-HasEnvironment/with.t b/t/classes/Dancer2-Core-Role-HasEnvironment/with.t
new file mode 100644
index 000000000..a5dff0c0e
--- /dev/null
+++ b/t/classes/Dancer2-Core-Role-HasEnvironment/with.t
@@ -0,0 +1,63 @@
+use strict;
+use warnings;
+use Test::More;
+use Test::Fatal;
+use Carp 'croak';
+
+use Dancer2::Core::Runner;
+use Dancer2::FileUtils qw/dirname path/;
+use File::Spec;
+use File::Temp;
+
+# undefine ENV vars used as defaults for app environment in these tests
+local $ENV{DANCER_ENVIRONMENT};
+local $ENV{PLACK_ENV};
+
+my $runner = Dancer2::Core::Runner->new();
+my $location = File::Spec->rel2abs( path( dirname(__FILE__), 'config' ) );
+my $location2 = File::Spec->rel2abs( path( dirname(__FILE__), 'config2' ) );
+
+{
+    package Dancer2::Test::TestRoleOne;
+    use Moo;
+    with 'Dancer2::Core::Role::HasEnvironment';
+}
+
+{
+    undef $ENV{DANCER_ENVIRONMENT};
+    undef $ENV{PLACK_ENV};
+    my $test_one = Dancer2::Test::TestRoleOne->new();
+    is( $test_one->environment, 'development', 'Default env is OK' );
+}
+{
+    $ENV{DANCER_ENVIRONMENT} = 'staging';
+    undef $ENV{PLACK_ENV};
+    my $test_one = Dancer2::Test::TestRoleOne->new();
+    is( $test_one->environment, q{staging}, 'Dancer env is OK when dancer env has value and plack env is not defined' );
+}
+{
+    $ENV{DANCER_ENVIRONMENT} = 'staging';
+    $ENV{PLACK_ENV} = 'other_env';
+    my $test_one = Dancer2::Test::TestRoleOne->new();
+    is( $test_one->environment, q{staging}, 'Dancer env is OK when dancer and plack env vars are both used' );
+}
+{
+    undef $ENV{DANCER_ENVIRONMENT};
+    $ENV{PLACK_ENV} = 'plack_env';
+    my $test_one = Dancer2::Test::TestRoleOne->new();
+    is( $test_one->environment, q{plack_env}, 'Dancer env is OK when dancer env var is not defined' );
+}
+{
+    $ENV{DANCER_ENVIRONMENT} = '';
+    $ENV{PLACK_ENV} = 'plack_env';
+    my $test_one = Dancer2::Test::TestRoleOne->new();
+    is( $test_one->environment, q{plack_env}, 'Dancer env is OK when one env var is empty string' );
+}
+{
+    $ENV{DANCER_ENVIRONMENT} = '';
+    $ENV{PLACK_ENV} = '';
+    my $test_one = Dancer2::Test::TestRoleOne->new();
+    is( $test_one->environment, q{development}, 'Dancer env is OK when both env vars are empty string' );
+}
+
+done_testing;

From 15bff9a42a2e7115814eff0f238efd2f3ee5ddbf Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Sun, 8 May 2022 20:17:29 +0200
Subject: [PATCH 13/23] Add more logging to ConfigReader::File::Simple

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 lib/Dancer2/ConfigReader/File/Simple.pm | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/Dancer2/ConfigReader/File/Simple.pm b/lib/Dancer2/ConfigReader/File/Simple.pm
index 85df8f420..c35a2d8e5 100644
--- a/lib/Dancer2/ConfigReader/File/Simple.pm
+++ b/lib/Dancer2/ConfigReader/File/Simple.pm
@@ -47,6 +47,7 @@ sub _build_config_files {
     my ($self) = @_;
 
     my $location = $self->config_location;
+    warn "Searching config files in location: $location\n" if $ENV{DANCER_CONFIG_VERBOSE};
     # an undef location means no config files for the caller
     return [] unless defined $location;
 
@@ -81,6 +82,7 @@ sub _build_config_files {
         }
     }
 
+    warn "Found following config files: @files\n" if $ENV{DANCER_CONFIG_VERBOSE};
     return \@files;
 }
 

From f9366ffe4e7049e1237ea368b50c311606b13977 Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Sun, 8 May 2022 20:18:17 +0200
Subject: [PATCH 14/23] Add isa type to HasLocation::location

Also specify lazy => 1.

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 lib/Dancer2/Core/Role/HasLocation.pm | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/Dancer2/Core/Role/HasLocation.pm b/lib/Dancer2/Core/Role/HasLocation.pm
index e37d2e531..12c716795 100644
--- a/lib/Dancer2/Core/Role/HasLocation.pm
+++ b/lib/Dancer2/Core/Role/HasLocation.pm
@@ -24,6 +24,8 @@ has caller => (
 
 has location => (
     is      => 'ro',
+    isa     => Str,
+    lazy    => 1,
     builder => '_build_location',
 );
 

From 50d009f01309385447f42a4cbeb0402235908196 Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Sun, 8 May 2022 20:20:46 +0200
Subject: [PATCH 15/23] Separate normalizers from Config to ConfigUtils

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 lib/Dancer2/ConfigUtils.pm | 41 ++++++++++++++++++++++++++++++++++++++
 t/config_utils.t           | 17 ++++++++++++++++
 2 files changed, 58 insertions(+)
 create mode 100644 lib/Dancer2/ConfigUtils.pm
 create mode 100644 t/config_utils.t

diff --git a/lib/Dancer2/ConfigUtils.pm b/lib/Dancer2/ConfigUtils.pm
new file mode 100644
index 000000000..3854f952b
--- /dev/null
+++ b/lib/Dancer2/ConfigUtils.pm
@@ -0,0 +1,41 @@
+package Dancer2::ConfigUtils;
+# ABSTRACT: Config utility helpers
+
+use strict;
+use warnings;
+
+use Carp;
+use Module::Runtime qw{ require_module };
+
+use Exporter 'import';
+our @EXPORT_OK = qw(
+    normalize_config_entry
+);
+
+my $NORMALIZERS = {
+    charset => sub {
+        my ($charset) = @_;
+        return $charset if !length( $charset || '' );
+
+        require_module('Encode');
+        my $encoding = Encode::find_encoding($charset);
+        croak
+          "Charset defined in configuration is wrong : couldn't identify '$charset'"
+          unless defined $encoding;
+        my $name = $encoding->name;
+
+        # Perl makes a distinction between the usual perl utf8, and the strict
+        # utf8 charset. But we don't want to make this distinction
+        $name = 'utf-8' if $name eq 'utf-8-strict';
+        return $name;
+    },
+};
+
+sub normalize_config_entry {
+    my ( $name, $value ) = @_;
+    $value = $NORMALIZERS->{$name}->($value)
+      if exists $NORMALIZERS->{$name};
+    return $value;
+}
+
+1;
diff --git a/t/config_utils.t b/t/config_utils.t
new file mode 100644
index 000000000..cd49676d4
--- /dev/null
+++ b/t/config_utils.t
@@ -0,0 +1,17 @@
+use strict;
+use warnings;
+
+use Test::More;
+use Test::Fatal;
+
+use Dancer2::ConfigUtils qw/normalize_config_entry/;
+
+is( normalize_config_entry( 'charset', 'UTF-8' ), 'utf-8', 'normalized UTF-8 to utf-8');
+
+like(
+    exception { normalize_config_entry( 'charset', 'BOGUS' ) },
+    qr{Charset defined in configuration is wrong : couldn't identify 'BOGUS'},
+    'Configuration file charset failure',
+);
+
+done_testing;

From 5dcf7885937a25c6edc2998996ec90b277925ee9 Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Sun, 8 May 2022 20:23:54 +0200
Subject: [PATCH 16/23] Split Role::Config to ConfigReader and Role::HasConfig

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 .../{Core/Role/Config.pm => ConfigReader.pm}  | 195 +++---------------
 lib/Dancer2/Core/App.pm                       |  52 ++++-
 lib/Dancer2/Core/Role/HasConfig.pm            | 158 ++++++++++++++
 t/classes/Dancer2-Core-Role-HasConfig/with.t  |  42 ++++
 t/config.t                                    |  92 +++++++++
 t/config_role.t                               | 159 --------------
 6 files changed, 369 insertions(+), 329 deletions(-)
 rename lib/Dancer2/{Core/Role/Config.pm => ConfigReader.pm} (54%)
 create mode 100644 lib/Dancer2/Core/Role/HasConfig.pm
 create mode 100644 t/classes/Dancer2-Core-Role-HasConfig/with.t
 create mode 100644 t/config.t
 delete mode 100644 t/config_role.t

diff --git a/lib/Dancer2/Core/Role/Config.pm b/lib/Dancer2/ConfigReader.pm
similarity index 54%
rename from lib/Dancer2/Core/Role/Config.pm
rename to lib/Dancer2/ConfigReader.pm
index ca83bdf2a..2d77b89c6 100644
--- a/lib/Dancer2/Core/Role/Config.pm
+++ b/lib/Dancer2/ConfigReader.pm
@@ -1,33 +1,36 @@
-# ABSTRACT: Config role for Dancer2 core objects
-package Dancer2::Core::Role::Config;
+# ABSTRACT: Config reader for Dancer2 App
+package Dancer2::ConfigReader;
 
-use Moo::Role;
+use Moo;
 
 use File::Spec;
 use Config::Any;
 use Hash::Merge::Simple;
 use Carp 'croak';
-use Module::Runtime qw{ require_module use_module };
+use Module::Runtime qw{ use_module };
 
 use Dancer2::Core::Factory;
 use Dancer2::Core;
 use Dancer2::Core::Types;
-use Dancer2::FileUtils 'path';
+use Dancer2::ConfigUtils 'normalize_config_entry';
 
-with 'Dancer2::Core::Role::HasLocation';
+has location => (
+    is       => 'ro',
+    isa      => Str,
+    required => 1,
+);
 
 has default_config => (
     is      => 'ro',
     isa     => HashRef,
-    lazy    => 1,
-    builder => '_build_default_config',
+    required => 1,
 );
 
 has config_location => (
     is      => 'ro',
     isa     => ReadableFilePath,
     lazy    => 1,
-    default => sub { $ENV{DANCER_CONFDIR} || $_[0]->location },
+    default => sub { $_[0]->location },
 );
 
 # The type for this attribute is Str because we don't require
@@ -40,8 +43,7 @@ has environments_location => (
     lazy    => 1,
     default => sub {
         $ENV{DANCER_ENVDIR}
-          || File::Spec->catdir( $_[0]->config_location, 'environments' )
-          || File::Spec->catdir( $_[0]->location,        'environments' );
+          || File::Spec->catdir( $_[0]->config_location, 'environments' );
     },
 );
 
@@ -55,64 +57,23 @@ has config => (
 has environment => (
     is      => 'ro',
     isa     => Str,
-    lazy    => 1,
-    builder => '_build_environment',
+    required => 1,
 );
 
 has config_readers => (
     is      => 'ro',
     lazy    => 1,
+    #isa     => ArrayRef[ InstanceOf['Dancer2::Core::Role::ConfigReader'] ],
     isa     => ArrayRef,
     builder => '_build_config_readers',
 );
 
-has local_triggers => (
-    is      => 'ro',
-    isa     => HashRef,
-    default => sub { +{} },
-);
-
-has global_triggers => (
-    is      => 'ro',
-    isa     => HashRef,
-    default => sub {
-        my $triggers = {
-            traces => sub {
-                my ( $self, $traces ) = @_;
-                # Carp is already a dependency
-                $Carp::Verbose = $traces ? 1 : 0;
-            },
-        };
-
-        my $runner_config;
-        {
-            no warnings 'once';
-            $runner_config = defined $Dancer2::runner
-                           ? Dancer2->runner->config
-                           : {};
-        }
-
-        for my $global ( keys %$runner_config ) {
-            next if exists $triggers->{$global};
-            $triggers->{$global} = sub {
-                my ($self, $value) = @_;
-                Dancer2->runner->config->{$global} = $value;
-            }
-        }
-
-        return $triggers;
-    },
-);
-
-sub _build_default_config { +{} }
-
-sub _build_environment { 'development' }
-
-# The new config builder
+# The config builder
 sub _build_config {
     my ($self) = @_;
 
     my $default  = $self->default_config;
+    use Data::Dumper;
     my $config = Hash::Merge::Simple->merge(
         $default,
         map {
@@ -125,6 +86,16 @@ sub _build_config {
     return $config;
 }
 
+sub _normalize_config {
+    my ( $self, $config ) = @_;
+
+    foreach my $key ( keys %{$config} ) {
+        my $value = $config->{$key};
+        $config->{$key} = normalize_config_entry( $key, $value );
+    }
+    return $config;
+}
+
 sub _build_config_readers {
     my ($self) = @_;
 
@@ -132,6 +103,7 @@ sub _build_config_readers {
                             ? (split qr{ \s+ }msx, $ENV{'DANCER_CONFIG_READERS'})
                             : ( q{Dancer2::ConfigReader::File::Simple} );
 
+    warn "ConfigReaders to use: @config_reader_names\n" if $ENV{DANCER_CONFIG_VERBOSE};
     return [
         map use_module($_)->new(
             location    => $self->location,
@@ -140,100 +112,6 @@ sub _build_config_readers {
     ];
 }
 
-sub _set_config_entries {
-    my ( $self, @args ) = @_;
-    my $no = scalar @args;
-    while (@args) {
-        $self->_set_config_entry( shift(@args), shift(@args) );
-    }
-    return $no;
-}
-
-sub _set_config_entry {
-    my ( $self, $name, $value ) = @_;
-
-    $value = $self->_normalize_config_entry( $name, $value );
-    $value = $self->_compile_config_entry( $name, $value, $self->config );
-    $self->config->{$name} = $value;
-}
-
-sub _normalize_config {
-    my ( $self, $config ) = @_;
-
-    foreach my $key ( keys %{$config} ) {
-        my $value = $config->{$key};
-        $config->{$key} = $self->_normalize_config_entry( $key, $value );
-    }
-    return $config;
-}
-
-sub _compile_config {
-    my ( $self, $config ) = @_;
-
-    foreach my $key ( keys %{$config} ) {
-        my $value = $config->{$key};
-        $config->{$key} =
-          $self->_compile_config_entry( $key, $value, $config );
-    }
-    return $config;
-}
-
-sub settings { shift->config }
-
-sub setting {
-    my $self = shift;
-    my @args = @_;
-
-    return ( scalar @args == 1 )
-      ? $self->settings->{ $args[0] }
-      : $self->_set_config_entries(@args);
-}
-
-sub has_setting {
-    my ( $self, $name ) = @_;
-    return exists $self->config->{$name};
-}
-
-# private
-
-my $_normalizers = {
-    charset => sub {
-        my ($charset) = @_;
-        return $charset if !length( $charset || '' );
-
-        require_module('Encode');
-        my $encoding = Encode::find_encoding($charset);
-        croak
-          "Charset defined in configuration is wrong : couldn't identify '$charset'"
-          unless defined $encoding;
-        my $name = $encoding->name;
-
-        # Perl makes a distinction between the usual perl utf8, and the strict
-        # utf8 charset. But we don't want to make this distinction
-        $name = 'utf-8' if $name eq 'utf-8-strict';
-        return $name;
-    },
-};
-
-sub _normalize_config_entry {
-    my ( $self, $name, $value ) = @_;
-    $value = $_normalizers->{$name}->($value)
-      if exists $_normalizers->{$name};
-    return $value;
-}
-
-sub _compile_config_entry {
-    my ( $self, $name, $value, $config ) = @_;
-
-    my $trigger = exists $self->local_triggers->{$name} ?
-                         $self->local_triggers->{$name} :
-                         $self->global_triggers->{$name};
-
-    defined $trigger or return $value;
-
-    return $trigger->( $self, $value, $config );
-}
-
 1;
 
 __END__
@@ -339,21 +217,10 @@ Gets the directory where the environment files are stored.
 =attr config
 
 Returns the whole configuration.
+This must not be used directly.
+Instead, use this via C<Dancer2::Core::Role::HasConfig> role
+which manages configuration after it is created.
 
 =attr environment
 
 Returns the name of the environment.
-
-=head1 METHODS
-
-=head2 settings
-
-Alias for config. Equivalent to <<$object->config>>.
-
-=head2 setting
-
-Get or set an element from the configuration.
-
-=head2 has_setting
-
-Verifies that a key exists in the configuration.
diff --git a/lib/Dancer2/Core/App.pm b/lib/Dancer2/Core/App.pm
index c9d0a49fb..7bab282f2 100644
--- a/lib/Dancer2/Core/App.pm
+++ b/lib/Dancer2/Core/App.pm
@@ -19,6 +19,7 @@ use Plack::Middleware::Conditional;
 use Plack::Middleware::ConditionalGET;
 
 use Dancer2::FileUtils 'path';
+use Dancer2::ConfigReader;
 use Dancer2::Core;
 use Dancer2::Core::Cookie;
 use Dancer2::Core::Error;
@@ -39,7 +40,9 @@ our $EVAL_SHIM; $EVAL_SHIM ||= sub {
 # we have hooks here
 with qw<
     Dancer2::Core::Role::Hookable
-    Dancer2::Core::Role::Config
+    Dancer2::Core::Role::HasConfig
+    Dancer2::Core::Role::HasLocation
+    Dancer2::Core::Role::HasEnvironment
 >;
 
 sub supported_engines { [ qw<logger serializer session template> ] }
@@ -213,7 +216,7 @@ sub _build_logger_engine {
     my $logger = $self->_factory->create(
         logger          => $value,
         %{$engine_options},
-        location        => $self->config_location,
+        location        => $self->config_reader->config_location,
         environment     => $self->environment,
         app_name        => $self->name,
         postponed_hooks => $self->postponed_hooks
@@ -405,16 +408,53 @@ has session => (
     predicate => '_has_session',
 );
 
-around _build_config => sub {
-    my ( $orig, $self ) = @_;
-    my $config          = $self->$orig;
+has config_reader => (
+    is      => 'ro',
+    isa     => InstanceOf['Dancer2::ConfigReader'],
+    lazy    => 0,
+    builder => '_build_config_reader',
+);
+
+sub _build_config_reader {
+    my ($self) = @_;
+    my $cfgr = Dancer2::ConfigReader->new(
+        environment    => $self->environment,
+        location       => $ENV{DANCER_CONFDIR}     || $self->location,
+        default_config => $self->_build_default_config(),
+    );
+    return $cfgr;
+}
+
+has '+config' => (
+    is      => 'ro',
+    isa     => HashRef,
+    lazy    => 1,
+    builder => '_build_config',
+);
+
+sub _build_config {
+    my ($self) = @_;
+
+    my $config_reader = $self->config_reader;
+    my $config = $config_reader->config;
 
     if ( $config && $config->{'engines'} ) {
         $self->_validate_engine($_) for keys %{ $config->{'engines'} };
     }
 
     return $config;
-};
+}
+
+# around _build_config => sub {
+#     my ( $orig, $self ) = @_;
+#     my $config          = $self->$orig;
+#
+#     if ( $config && $config->{'engines'} ) {
+#         $self->_validate_engine($_) for keys %{ $config->{'engines'} };
+#     }
+#
+#     return $config;
+# };
 
 sub _build_response {
     my $self = shift;
diff --git a/lib/Dancer2/Core/Role/HasConfig.pm b/lib/Dancer2/Core/Role/HasConfig.pm
new file mode 100644
index 000000000..50eb084e0
--- /dev/null
+++ b/lib/Dancer2/Core/Role/HasConfig.pm
@@ -0,0 +1,158 @@
+# ABSTRACT: Role that represents the config of Dancer2 App
+package Dancer2::Core::Role::HasConfig;
+
+use Moo::Role;
+
+use File::Spec;
+use Config::Any;
+use Hash::Merge::Simple;
+use Carp 'croak';
+use Module::Runtime qw{ require_module use_module };
+
+use Dancer2::Core::Factory;
+use Dancer2::Core;
+use Dancer2::Core::Types;
+use Dancer2::FileUtils 'path';
+use Dancer2::ConfigUtils 'normalize_config_entry';
+
+has config => (
+    is      => 'ro',
+    isa     => HashRef,
+    lazy    => 0,
+    builder => '_build_config',
+);
+
+has local_triggers => (
+    is      => 'ro',
+    isa     => HashRef,
+    default => sub { +{} },
+);
+
+has global_triggers => (
+    is      => 'ro',
+    isa     => HashRef,
+    default => sub {
+        my $triggers = {
+            traces => sub {
+                my ( $self, $traces ) = @_;
+                # Carp is already a dependency
+                $Carp::Verbose = $traces ? 1 : 0;
+            },
+        };
+
+        my $runner_config;
+        {
+            no warnings 'once';
+            $runner_config = defined $Dancer2::runner
+                           ? Dancer2->runner->config
+                           : {};
+        }
+
+        for my $global ( keys %$runner_config ) {
+            next if exists $triggers->{$global};
+            $triggers->{$global} = sub {
+                my ($self, $value) = @_;
+                Dancer2->runner->config->{$global} = $value;
+            }
+        }
+
+        return $triggers;
+    },
+);
+
+sub _set_config_entries {
+    my ( $self, @args ) = @_;
+    my $no = scalar @args;
+    while (@args) {
+        $self->_set_config_entry( shift(@args), shift(@args) );
+    }
+    return $no;
+}
+
+sub _set_config_entry {
+    my ( $self, $name, $value ) = @_;
+
+    $value = normalize_config_entry( $name, $value );
+    $value = $self->_compile_config_entry( $name, $value, $self->config );
+    $self->config->{$name} = $value;
+}
+
+# Who calls this method?
+# sub _compile_config {
+#     my ( $self, $config ) = @_;
+#
+#     foreach my $key ( keys %{$config} ) {
+#         my $value = $config->{$key};
+#         $config->{$key} =
+#           $self->_compile_config_entry( $key, $value, $config );
+#     }
+#     return $config;
+# }
+
+sub settings { shift->config }
+
+sub setting {
+    my $self = shift;
+    my @args = @_;
+
+    return ( scalar @args == 1 )
+      ? $self->settings->{ $args[0] }
+      : $self->_set_config_entries(@args);
+}
+
+sub has_setting {
+    my ( $self, $name ) = @_;
+    return exists $self->config->{$name};
+}
+
+# private
+
+sub _compile_config_entry {
+    my ( $self, $name, $value, $config ) = @_;
+
+    my $trigger = exists $self->local_triggers->{$name} ?
+                         $self->local_triggers->{$name} :
+                         $self->global_triggers->{$name};
+
+    defined $trigger or return $value;
+
+    return $trigger->( $self, $value, $config );
+}
+
+1;
+
+__END__
+
+=head1 DESCRIPTION
+
+This role provides a C<config> attribute that is
+used to read the configuration.
+When accessing
+the first time, it calls method C<_build_config()> which
+must be implemented by the using class.
+This method should return the whole config which has been
+created by executing one or more
+B<ConfigReader> packages.
+
+Also provides a C<setting()> method which is supposed to be used by externals to
+read/write config entries.
+
+=head1 ATTRIBUTES
+
+=attr config
+
+Returns the whole configuration.
+
+=head1 METHODS
+
+=head2 settings
+
+Alias for config. Equivalent to <<$object->config>>.
+
+=head2 setting
+
+Get or set an element from the configuration.
+
+=head2 has_setting
+
+Verifies that a key exists in the configuration.
diff --git a/t/classes/Dancer2-Core-Role-HasConfig/with.t b/t/classes/Dancer2-Core-Role-HasConfig/with.t
new file mode 100644
index 000000000..b0bd4fdbb
--- /dev/null
+++ b/t/classes/Dancer2-Core-Role-HasConfig/with.t
@@ -0,0 +1,42 @@
+use strict;
+use warnings;
+
+use Test::More;
+
+# undefine ENV vars used as defaults for app environment in these tests
+local $ENV{DANCER_ENVIRONMENT};
+local $ENV{PLACK_ENV};
+
+{
+
+    package Dev;
+    use Moo;
+    with 'Dancer2::Core::Role::HasConfig';
+
+    sub name {'Dev'}
+    sub _build_config {
+        return {
+            content_type => 'text/html',
+            charset      => 'UTF-8',
+            environment  => 'development',
+            template     => 'Tiny',
+        }
+    }
+
+}
+
+my $d = Dev->new();
+is $d->does('Dancer2::Core::Role::HasConfig'), 1,
+    'role Dancer2::Core::Role::Config is consumed';
+
+is $d->config->{'environment'}, 'development', 'Correct config value';
+is $d->config->{'template'}, 'Tiny', 'Correct config value';
+is $d->settings->{'charset'}, 'UTF-8', 'Correct config value normalized';
+
+$d->setting( 'entry_one', 'value_one', 'entry_two', 'value_two' );
+is $d->config->{'entry_one'}, 'value_one', 'Correct config value set';
+is $d->config->{'entry_two'}, 'value_two', 'Correct config value set';
+ok $d->has_setting('entry_one'), 'Has value we set previously';
+isnt $d->has_setting('entry_missing'), 1, 'Correctly missing value';
+
+done_testing;
diff --git a/t/config.t b/t/config.t
new file mode 100644
index 000000000..4f451eab6
--- /dev/null
+++ b/t/config.t
@@ -0,0 +1,92 @@
+use strict;
+use warnings;
+use Test::More;
+use Test::Fatal;
+use Carp 'croak';
+
+# use Dancer2::Core::Runner;
+use Dancer2::FileUtils qw/dirname path/;
+use File::Spec;
+use File::Temp;
+use Dancer2::ConfigReader;
+
+# undefine ENV vars used as defaults for app environment in these tests
+local $ENV{DANCER_ENVIRONMENT};
+local $ENV{PLACK_ENV};
+
+# my $runner = Dancer2::Core::Runner->new();
+my $location = File::Spec->rel2abs( path( dirname(__FILE__), 'config' ) );
+my $location2 = File::Spec->rel2abs( path( dirname(__FILE__), 'config2' ) );
+
+{ 
+    my $cfgr = Dancer2::ConfigReader->new(
+        environment    => 'my_env',
+        location       => $location,
+        default_config => {
+            content_type => 'text/html',
+            charset      => 'UTF-8',
+        },
+    );
+    is( $cfgr->config->{'application'}->{'some_feature'}, 'foo', 'Ok config' );
+    is( $cfgr->config->{'charset'}, 'utf-8', 'Ok default config' );
+}
+
+{ 
+    # note "bad YAML file: environments/failure.yml";
+    like(
+        exception {
+            Dancer2::ConfigReader->new(
+                environment    => 'failure',
+                location       => $location,
+                default_config => { },
+            )->config;
+        },
+        qr{Unable to parse the configuration file}, 'Configuration file parsing failure',
+    );
+}
+
+{
+    my $cfgr = Dancer2::ConfigReader->new(
+        environment    => 'any_env',
+        location       => $location,
+        default_config => { },
+    );
+    my $cfg = $cfgr->config;
+    isnt( $cfg, undef, 'OK config read' );
+}
+{
+    my $cfgr = Dancer2::ConfigReader->new(
+        environment    => 'merging',
+        location       => $location,
+        default_config => { },
+    );
+    # note "config merging";
+    # Check the 'application' top-level key; its the only key that
+    # is currently a HoH in the test configurations
+    is_deeply $cfgr->config->{application},
+        {
+            some_feature    => 'bar',
+            another_setting => 'baz',
+        },
+        "full merging of configuration hashes";
+}
+{
+    my $cfgr = Dancer2::ConfigReader->new(
+        environment    => 'lconfig',
+        location       => $location2,
+        default_config => { },
+    );
+    is_deeply $cfgr->config->{application},
+      { feature_1 => 'foo',
+        feature_2 => 'alpha',
+        feature_3 => 'replacement',
+        feature_4 => 'blat',
+        feature_5 => 'beta',
+        feature_6 => 'bar',
+        feature_7 => 'baz',
+        feature_8 => 'goober',
+      },
+      "full merging of local configuration hashes";
+}
+
+done_testing;
diff --git a/t/config_role.t b/t/config_role.t
deleted file mode 100644
index 97e060c9f..000000000
--- a/t/config_role.t
+++ /dev/null
@@ -1,159 +0,0 @@
-use strict;
-use warnings;
-use Test::More;
-use Test::Fatal;
-use Carp 'croak';
-
-use Dancer2::Core::Runner;
-use Dancer2::FileUtils qw/dirname path/;
-use File::Spec;
-use File::Temp;
-
-# undefine ENV vars used as defaults for app environment in these tests
-local $ENV{DANCER_ENVIRONMENT};
-local $ENV{PLACK_ENV};
-
-my $runner = Dancer2::Core::Runner->new();
-my $location = File::Spec->rel2abs( path( dirname(__FILE__), 'config' ) );
-my $location2 = File::Spec->rel2abs( path( dirname(__FILE__), 'config2' ) );
-
-{
-
-    package Prod;
-    use Moo;
-    with 'Dancer2::Core::Role::Config';
-
-    sub name {'Prod'}
-
-    sub _build_environment    {'production'}
-    sub _build_location       {$location}
-    sub _build_default_config {$runner->config}
-
-    package Dev;
-    use Moo;
-    with 'Dancer2::Core::Role::Config';
-
-    sub _build_environment    {'development'}
-    sub _build_location       {$location};
-    sub _build_default_config {$runner->config}
-
-    package Failure;
-    use Moo;
-    with 'Dancer2::Core::Role::Config';
-
-    sub _build_environment    {'failure'}
-    sub _build_location       {$location}
-    sub _build_default_config {$runner->config}
-
-    package Staging;
-    use Moo;
-    with 'Dancer2::Core::Role::Config';
-
-    sub _build_environment    {'staging'}
-    sub _build_location       {$location}
-    sub _build_default_config {$runner->config}
-
-    package Merging;
-    use Moo;
-    with 'Dancer2::Core::Role::Config';
-
-    sub name {'Merging'}
-
-    sub _build_environment    {'merging'}
-    sub _build_location       {$location}
-    sub _build_default_config {$runner->config}
-
-    package LocalConfig;
-    use Moo;
-    with 'Dancer2::Core::Role::Config';
-
-    sub name {'LocalConfig'}
-
-    sub _build_environment    {'lconfig'}
-    sub _build_location       {$location2}
-    sub _build_default_config {$runner->config}
-
-}
-
-my $d = Dev->new();
-
-my $f = Prod->new;
-is $f->does('Dancer2::Core::Role::Config'), 1,
-  "role Dancer2::Core::Role::Config is consumed";
-
-note "bad YAML file";
-my $fail = Failure->new;
-is $fail->environment, 'failure';
-
-like(
-    exception { $fail->config },
-    qr{Unable to parse the configuration file}, 'Configuration file parsing failure',
-);
-
-note "config merging";
-my $m = Merging->new;
-
-# Check the 'application' top-level key; its the only key that
-# is currently a HoH in the test configurations
-is_deeply $m->config->{application},
-  { some_feature    => 'bar',
-    another_setting => 'baz',
-  },
-  "full merging of configuration hashes";
-
-{
-    my $l = LocalConfig->new;
-
-    is_deeply $l->config->{application},
-      { feature_1 => 'foo',
-        feature_2 => 'alpha',
-        feature_3 => 'replacement',
-        feature_4 => 'blat',
-        feature_5 => 'beta',
-        feature_6 => 'bar',
-        feature_7 => 'baz',
-        feature_8 => 'goober',
-      },
-      "full merging of local configuration hashes";
-
-}
-
-note "config parsing";
-
-is $f->config->{show_stacktrace}, 0;
-is $f->config->{main},        1;
-is $f->config->{charset},     'utf-8', "normalized UTF-8 to utf-8";
-
-ok( $f->has_setting('charset') );
-ok( !$f->has_setting('foobarbaz') );
-
-note "default values";
-is $f->setting('apphandler'),   'Standalone';
-
-like(
-    exception { $f->_normalize_config( { charset => 'BOGUS' } ) },
-    qr{Charset defined in configuration is wrong : couldn't identify 'BOGUS'},
-    'Configuration file charset failure',
-);
-
-{
-
-    package Foo;
-    use Carp 'croak';
-    sub foo { croak "foo" }
-}
-
-is $f->setting('traces'), 0;
-unlike( exception { Foo->foo() }, qr{Foo::foo}, "traces are not enabled", );
-
-$f->setting( traces => 1 );
-like( exception { Foo->foo() }, qr{Foo::foo}, "traces are enabled", );
-
-{
-    my $tmpdir = File::Temp::tempdir( CLEANUP => 1, TMPDIR => 1 );
-    $ENV{DANCER_CONFDIR} = $tmpdir;
-    my $f = Prod->new;
-    is $f->config_location, $tmpdir;
-}
-
-done_testing;

From 94de9b0ebd3f4fba9219508db18d321dd97d5fe5 Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Sun, 8 May 2022 20:24:17 +0200
Subject: [PATCH 17/23] Add Mikko Koivunalho to contributors list

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 lib/Dancer2.pm | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/Dancer2.pm b/lib/Dancer2.pm
index f43580917..ea9ac2d0d 100644
--- a/lib/Dancer2.pm
+++ b/lib/Dancer2.pm
@@ -355,6 +355,7 @@ We are also on IRC: #dancer on irc.perl.org.
     Michael Kröll
     Michał Wojciechowski
     Mike Katasonov
+    Mikko Koivunalho
     Mohammad S Anwar
     mokko
     Nick Patch

From 444764668308c209a11bc694ac4f911cfef7a1be Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Thu, 12 May 2022 18:48:03 +0200
Subject: [PATCH 18/23] Cleanup code

* Remove previously commented out code
* Remove 'use Data::Dumper'

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 lib/Dancer2/ConfigReader.pm        |  2 --
 lib/Dancer2/Core/App.pm            | 11 -----------
 lib/Dancer2/Core/Role/HasConfig.pm | 12 ------------
 3 files changed, 25 deletions(-)

diff --git a/lib/Dancer2/ConfigReader.pm b/lib/Dancer2/ConfigReader.pm
index 2d77b89c6..273400b3e 100644
--- a/lib/Dancer2/ConfigReader.pm
+++ b/lib/Dancer2/ConfigReader.pm
@@ -63,7 +63,6 @@ has environment => (
 has config_readers => (
     is      => 'ro',
     lazy    => 1,
-    #isa     => ArrayRef[ InstanceOf['Dancer2::Core::Role::ConfigReader'] ],
     isa     => ArrayRef,
     builder => '_build_config_readers',
 );
@@ -73,7 +72,6 @@ sub _build_config {
     my ($self) = @_;
 
     my $default  = $self->default_config;
-    use Data::Dumper;
     my $config = Hash::Merge::Simple->merge(
         $default,
         map {
diff --git a/lib/Dancer2/Core/App.pm b/lib/Dancer2/Core/App.pm
index 7bab282f2..6e242bda4 100644
--- a/lib/Dancer2/Core/App.pm
+++ b/lib/Dancer2/Core/App.pm
@@ -445,17 +445,6 @@ sub _build_config {
     return $config;
 }
 
-# around _build_config => sub {
-#     my ( $orig, $self ) = @_;
-#     my $config          = $self->$orig;
-#
-#     if ( $config && $config->{'engines'} ) {
-#         $self->_validate_engine($_) for keys %{ $config->{'engines'} };
-#     }
-#
-#     return $config;
-# };
-
 sub _build_response {
     my $self = shift;
     return Dancer2::Core::Response->new(
diff --git a/lib/Dancer2/Core/Role/HasConfig.pm b/lib/Dancer2/Core/Role/HasConfig.pm
index 50eb084e0..f506396f6 100644
--- a/lib/Dancer2/Core/Role/HasConfig.pm
+++ b/lib/Dancer2/Core/Role/HasConfig.pm
@@ -77,18 +77,6 @@ sub _set_config_entry {
     $self->config->{$name} = $value;
 }
 
-# Who calls this method?
-# sub _compile_config {
-#     my ( $self, $config ) = @_;
-#
-#     foreach my $key ( keys %{$config} ) {
-#         my $value = $config->{$key};
-#         $config->{$key} =
-#           $self->_compile_config_entry( $key, $value, $config );
-#     }
-#     return $config;
-# }
-
 sub settings { shift->config }
 
 sub setting {

From e598fbf68280442907a22f1560ffd30712f28001 Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Thu, 12 May 2022 19:00:19 +0200
Subject: [PATCH 19/23] Fix documentation in File::Simple

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 lib/Dancer2/ConfigReader/File/Simple.pm | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/lib/Dancer2/ConfigReader/File/Simple.pm b/lib/Dancer2/ConfigReader/File/Simple.pm
index c35a2d8e5..0e8b6a5bc 100644
--- a/lib/Dancer2/ConfigReader/File/Simple.pm
+++ b/lib/Dancer2/ConfigReader/File/Simple.pm
@@ -116,9 +116,7 @@ It reads the configuration files of C<Dancer2>.
 Please see C<Dancer2::Config> for more information.
 
 If you need to add additional functionality to the reading
-mechanism, you can extend this class. An example of this is
-in: B</t/lib/Dancer2/ConfigReader/File/Extended.pm>
-
+mechanism, you can extend this class.
 An example of this is providing the possibility to replace
 random parts of the file config with environmental variables:
 
@@ -193,7 +191,7 @@ random parts of the file config with environmental variables:
 
 =attr name
 
-The name of the class.
+The name of the Config Reader class: C<File::Simple>.
 
 =attr location
 

From 6959f974afef5e19da6fda8a6ca35f770f869fa1 Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Thu, 12 May 2022 19:38:03 +0200
Subject: [PATCH 20/23] Fix test to use File::Simple->config_location

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 t/issues/gh-634.t | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/t/issues/gh-634.t b/t/issues/gh-634.t
index 01ce44ea6..04bd4eaff 100644
--- a/t/issues/gh-634.t
+++ b/t/issues/gh-634.t
@@ -5,6 +5,11 @@ use File::Temp qw/tempdir/;
 use File::Spec;
 
 my $log_dir = tempdir( CLEANUP => 1 );
+sub config_location {
+    my ($app) = @_;
+    my %config_readers = map { $_->{name} => $_ } @{ $app->config_reader->config_readers };
+    return $config_readers{ 'File::Simple' }->config_location;
+}
 
 {
     package LogDirSpecified;
@@ -56,7 +61,7 @@ my $check_cb = sub {
 
     is(
         $logger->location,
-        $app->config_location,
+        config_location( $app ),
         'Logger got correct location',
     );
 
@@ -96,7 +101,7 @@ subtest 'test Logger::File with log_dir NOT specified' => sub {
 
     $check_cb->(
         $app,
-        File::Spec->catdir( $app->config_location, 'logs' ),
+        File::Spec->catdir( config_location( $app ), 'logs' ),
         $app->environment . '.log',
     );
 };
@@ -116,4 +121,3 @@ subtest 'test Logger::File with non-existent log_dir specified' => sub {
         'test_log.log',
     );
 };
-

From 99d934affd8580012b542cab437cd70635800e3e Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Thu, 12 May 2022 19:47:05 +0200
Subject: [PATCH 21/23] Fix documentation in Role::ConfigReader

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 lib/Dancer2/Core/Role/ConfigReader.pm | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/lib/Dancer2/Core/Role/ConfigReader.pm b/lib/Dancer2/Core/Role/ConfigReader.pm
index b63fe1fa6..cfc3c529c 100644
--- a/lib/Dancer2/Core/Role/ConfigReader.pm
+++ b/lib/Dancer2/Core/Role/ConfigReader.pm
@@ -79,13 +79,19 @@ during creation:
 The name of the environment used, e.g.
 production, development, staging.
 
-==attr location
+=attr location
 
-Absolute path to the directory where the server started.
+The absolute path to the directory where the server started.
+
+=attr default_config
+
+A hash ref which contains the default values.
 
 These arguments are passed when the object is created by
-C<Dancer2::Core::Role::Config>. How the config
-reader applies them as it needs.
+C<Dancer2::Core::App>. 
+ConfigReader then passes C<environment> and C<location> forward to every
+config reader class when it instantiates them.
+How the config reader applies them, depend on its needs.
 
 Provides a C<config> attribute that - when accessing
 the first time - feeds itself by finding and parsing

From 8bf2e6d6266b9a211657e6574c90db775a08c852 Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Sun, 21 Aug 2022 15:31:59 +0200
Subject: [PATCH 22/23] Remove whitespace

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 lib/Dancer2.pm                        | 2 +-
 lib/Dancer2/Core/Role/ConfigReader.pm | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/Dancer2.pm b/lib/Dancer2.pm
index ea9ac2d0d..00cf9401f 100644
--- a/lib/Dancer2.pm
+++ b/lib/Dancer2.pm
@@ -134,7 +134,7 @@ Dancer2 is easy and fun:
 
     use Dancer2;
     get '/' => sub { "Hello World" };
-    dance; 
+    dance;
 
 This is the main module for the Dancer2 distribution. It contains logic for
 creating a new Dancer2 application.
diff --git a/lib/Dancer2/Core/Role/ConfigReader.pm b/lib/Dancer2/Core/Role/ConfigReader.pm
index cfc3c529c..a0c1f6e14 100644
--- a/lib/Dancer2/Core/Role/ConfigReader.pm
+++ b/lib/Dancer2/Core/Role/ConfigReader.pm
@@ -88,7 +88,7 @@ The absolute path to the directory where the server started.
 A hash ref which contains the default values.
 
 These arguments are passed when the object is created by
-C<Dancer2::Core::App>. 
+C<Dancer2::Core::App>.
 ConfigReader then passes C<environment> and C<location> forward to every
 config reader class when it instantiates them.
 How the config reader applies them, depend on its needs.

From 35ad84961334da2da03226b7ddc736f24174a804 Mon Sep 17 00:00:00 2001
From: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
Date: Sat, 10 Sep 2022 23:12:42 +0200
Subject: [PATCH 23/23] Add Mikko Koivunalho to contributors

Signed-off-by: Mikko Johannes Koivunalho <mikko.koivunalho@iki.fi>
---
 README.mkdn | 1 +
 1 file changed, 1 insertion(+)

diff --git a/README.mkdn b/README.mkdn
index 34a2b2001..75decdcbb 100644
--- a/README.mkdn
+++ b/README.mkdn
@@ -232,6 +232,7 @@ We are also on IRC: #dancer on irc.perl.org.
     Michael Kröll
     Michał Wojciechowski
     Mike Katasonov
+    Mikko Koivunalho
     Mohammad S Anwar
     mokko
     Nick Patch