Use empty IO on null input (#102)

* Use empty IO on `null` input
* Bump versions

Author: Blacksmoke16

README.md

@@ -68,7 +68,7 @@ The built binary will be available as `./bin/oq`.  This can be relocated elsewhe
 
 ```dockerfile
 # Set an arg to store the oq version that should be installed.
-ARG OQ_VERSION=1.3.0
+ARG OQ_VERSION=1.3.1
 
 # Grab the binary from the latest Github release and make it executable; placing it within /usr/local/bin.  Can also put it elsewhere if you so desire.
 RUN wget https://github.com/Blacksmoke16/oq/releases/download/v${OQ_VERSION}/oq-v${OQ_VERSION}-linux-x86_64 -O /usr/local/bin/oq && chmod +x /usr/local/bin/oq

shard.yml

@@ -3,7 +3,7 @@ name: oq
 description: |
   A performant, and portable jq wrapper thats facilitates the consumption and output of formats other than JSON; using jq filters to transform the data.
 
-version: 1.3.0
+version: 1.3.1
 
 authors:
   - George Dietrich <[email protected]>

snap/snapcraft.yaml

@@ -1,5 +1,5 @@
 name: oq
-version: '1.3.0'
+version: '1.3.1'
 summary: A performant, and portable jq wrapper to support formats other than JSON
 description: |
   A performant, and portable jq wrapper thats facilitates the consumption and output of formats other than JSON; using jq filters to transform the data.

spec/oq_spec.cr

@@ -135,23 +135,29 @@ describe OQ do
           output.should eq "0\n"
         end
       end
+    end
 
-      describe "with a JSON object string" do
-        it "should return the correct output" do
-          run_binary(args: ["-cn", %([{"foo":"bar"},{"foo":"baz"}])]) do |output|
-            output.should eq %([{"foo":"bar"},{"foo":"baz"}]\n)
-          end
+    describe "with a JSON object string" do
+      it "should return the correct output" do
+        run_binary(args: ["-cn", %([{"foo":"bar"},{"foo":"baz"}])]) do |output|
+          output.should eq %([{"foo":"bar"},{"foo":"baz"}]\n)
         end
       end
+    end
 
-      describe "with input from STDIN" do
-        it "should return the correct output" do
-          run_binary(input: "foo", args: ["-n", "."]) do |output|
-            output.should eq "null\n"
-          end
+    describe "with input from STDIN" do
+      it "should return the correct output" do
+        run_binary(input: "foo", args: ["-n", "."]) do |output|
+          output.should eq "null\n"
         end
       end
     end
+
+    it "should not block waiting for input" do
+      run_binary(input: Process::Redirect::Inherit, args: ["-n", "."]) do |output|
+        output.should eq "null\n"
+      end
+    end
   end
 
   describe "with a custom indent value with JSON" do

spec/spec_helper.cr

@@ -2,12 +2,19 @@ require "spec"
 require "../src/oq"
 
 # Runs the the binary with the given *name* and *args*.
-def run_binary(input : String? = nil, name : String = "bin/oq", args : Array(String) = [] of String, *, success : Bool = true, file = __FILE__, line = __LINE__, & : String, Process::Status, String -> Nil)
+def run_binary(input : String | Process::Redirect | Nil = nil, name : String = "bin/oq", args : Array(String) = [] of String, *, success : Bool = true, file = __FILE__, line = __LINE__, & : String, Process::Status, String -> Nil)
   buffer_io = IO::Memory.new
   error_io = IO::Memory.new
   input_io = IO::Memory.new
-  input_io << input if input
-  status = Process.run(name, args, output: buffer_io, input: input_io.rewind, error: error_io)
+
+  if input.is_a? Process::Redirect
+    input_io = input
+  else
+    input_io << input if input
+    input_io = input_io.rewind
+  end
+
+  status = Process.run(name, args, output: buffer_io, input: input_io, error: error_io)
 
   if success
     status.success?.should be_true, file: file, line: line

src/oq.cr

@@ -6,7 +6,7 @@ require "./converters/*"
 
 # A performant, and portable jq wrapper thats facilitates the consumption and output of formats other than JSON; using jq filters to transform the data.
 module OQ
-  VERSION = "1.3.0"
+  VERSION = "1.3.1"
 
   # The support formats that can be converted to/from.
   enum Format
@@ -83,6 +83,9 @@ module OQ
     # If a tab for each indentation level instead of spaces.
     property? tab : Bool
 
+    # Do not read any input, using `null` as the singular input value.
+    property? null : Bool
+
     # If XML namespaces should be parsed as well.
     # TODO: Remove this in oq 2.0 as it'll becomethe default.
     property? xmlns : Bool
@@ -107,6 +110,7 @@ module OQ
       @xml_item : String = "item",
       @indent : Int32 = 2,
       @tab : Bool = false,
+      @null : Bool = false,
       @xmlns : Bool = false
     )
     end
@@ -157,9 +161,10 @@ module OQ
       # TODO: Remove this in oq 2.x
       raise ArgumentError.new "The `--xml-namespace-alias` option must be used with the `--xmlns` option." if !@xmlns && !@xml_namespaces.empty?
 
-      # Replace the *input* with a fake `ARGF` `IO` to handle both file and `IO` inputs
-      # in case `ARGV` is not being used for the input arguments.
-      input = IO::ARGF.new input_args, input
+      # Replace the *input* with a fake `ARGF` `IO` to handle both file and `IO` inputs in case `ARGV` is not being used for the input arguments.
+      #
+      # If using `null` input, set the input to an empty memory `IO` to essentially consume nothing.
+      input = @null ? IO::Memory.new : IO::ARGF.new input_args, input
 
       input_read, input_write = IO.pipe
       output_read, output_write = IO.pipe

src/oq_cli.cr

@@ -28,6 +28,7 @@ OptionParser.parse do |parser|
   parser.on("-o FORMAT", "--output FORMAT", "Format of the output data. Supported formats: #{OQ::Format}") { |format| (f = OQ::Format.parse?(format)) ? processor.output_format = f : abort "Invalid output format: '#{format}'" }
   parser.on("--indent NUMBER", "Use the given number of spaces for indentation (JSON/XML only).") { |n| processor.indent = n.to_i; processor.add_arg "--indent"; processor.add_arg n }
   parser.on("--tab", "Use a tab for each indentation level instead of two spaces.") { processor.tab = true; processor.add_arg "--tab" }
+  parser.on("-n", "--null-input", "Don't read any input at all, running the filter once using `null` as the input.") { processor.null = true; processor.add_arg "--null-input" }
   parser.on("--no-prolog", "Whether the XML prolog should be emitted if converting to XML.") { processor.xml_prolog = false }
   parser.on("--xml-item NAME", "The name for XML array elements without keys.") { |i| processor.xml_item = i }
   parser.on("--xmlns", "If XML namespaces should be parsed.  NOTE: This will become the default in oq 2.x.") { processor.xmlns = true }