diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 095dcc5..294b855 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -12,7 +12,6 @@ jobs:
       MIX_ENV: test
       EVENTSTORE_HOST: localhost
       EVENTSTORE_VERSION: nightly
-
     steps:
     - name: Checkout
       uses: actions/checkout@v3
@@ -20,35 +19,28 @@ jobs:
     - name: Spawn docker-compose EventStoreDB container
       run: docker-compose up --detach eventstore
 
-    - name: Determine the elixir version
-      run: echo "ELIXIR_VERSION=$(grep -h elixir .tool-versions | awk '{ print $2 }' | awk -F - '{print $1}')" >> $GITHUB_ENV
-
-    - name: Determine the otp version
-      run: echo "OTP_VERSION=$(grep -h erlang .tool-versions | awk '{ print $2 }')" >> $GITHUB_ENV
-
     - name: Setup Elixir and Erlang versions
       uses: erlef/setup-beam@v1
+      id: beam
       with:
-        otp-version: ${{ env.OTP_VERSION }}
-        elixir-version: ${{ env.ELIXIR_VERSION }}
+        version-file: .tool-versions
+        version-type: strict
 
     - name: Restore the deps cache
       uses: actions/cache@v3
       id: deps-cache
       with:
+        key: ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-deps
+        restore-keys: ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-deps
         path: deps
-        key: ${{ runner.os }}-${{ env.ELIXIR_VERSION }}-${{ env.OTP_VERSION }}-${{ env.MIX_ENV }}-deps-mixlockhash-${{ hashFiles(format('{0}{1}', github.workspace, '/mix.lock')) }}
-        restore-keys: |
-          ${{ runner.os }}-${{ env.ELIXIR_VERSION }}-${{ env.OTP_VERSION }}-${{ env.MIX_ENV }}-deps-
 
     - name: Restore the _build cache
       uses: actions/cache@v3
       id: build-cache
       with:
+        key: ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-${{ env.MIX_ENV }}-build
+        restore-keys: ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-${{ env.MIX_ENV }}-build
         path: _build
-        key: ${{ runner.os }}-${{ env.ELIXIR_VERSION  }}-${{ env.OTP_VERSION }}-${{ env.MIX_ENV }}-build-mixlockhash-${{ hashFiles(format('{0}{1}', github.workspace, '/mix.lock')) }}
-        restore-keys: |
-          ${{ runner.os }}-${{ env.ELIXIR_VERSION }}-${{ env.OTP_VERSION }}-${{ env.MIX_ENV }}-build-
 
     - name: Fetch mix dependencies
       if: steps.deps-cache.outputs.cache-hit != 'true'
@@ -75,6 +67,29 @@ jobs:
     - name: Credo
       run: mix credo
 
+    - name: Restore PLT cache
+      uses: actions/cache/restore@v3
+      id: plt-cache
+      with:
+        key: ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-plt
+        restore-keys: ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-plt
+        path: priv/plts
+
+    - name: Create PLTs
+      shell: sh
+      if: steps.plt-cache.outputs.cache-hit != 'true'
+      run: mix dialyzer --plt
+
+    - name: Save PLT cache
+      uses: actions/cache/save@v3
+      if: steps.plt-cache.outputs.cache-hit != 'true'
+      with:
+        key: ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-plt
+        path: priv/plts
+
+    - name: Run dialyzer
+      run: mix dialyzer --format github
+
   publish-hex-package:
     name: Publish Hex Package ⬆️☁️
     runs-on: ubuntu-20.04
@@ -88,35 +103,28 @@ jobs:
     - name: Checkout
       uses: actions/checkout@v3
 
-    - name: Determine the elixir version
-      run: echo "ELIXIR_VERSION=$(grep -h elixir .tool-versions | awk '{ print $2 }' | awk -F - '{print $1}')" >> $GITHUB_ENV
-
-    - name: Determine the otp version
-      run: echo "OTP_VERSION=$(grep -h erlang .tool-versions | awk '{ print $2 }')" >> $GITHUB_ENV
-
     - name: Setup Elixir and Erlang versions
       uses: erlef/setup-beam@v1
+      id: beam
       with:
-        otp-version: ${{ env.OTP_VERSION }}
-        elixir-version: ${{ env.ELIXIR_VERSION }}
+        version-file: .tool-versions
+        version-type: strict
 
     - name: Restore the deps cache
       uses: actions/cache@v3
       id: deps-cache
       with:
+        key: ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-deps
+        restore-keys: ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-deps
         path: deps
-        key: ${{ runner.os }}-${{ env.ELIXIR_VERSION }}-${{ env.OTP_VERSION }}-${{ env.MIX_ENV }}-deps-mixlockhash-${{ hashFiles(format('{0}{1}', github.workspace, '/mix.lock')) }}
-        restore-keys: |
-          ${{ runner.os }}-${{ env.ELIXIR_VERSION }}-${{ env.OTP_VERSION }}-${{ env.MIX_ENV }}-deps-
 
     - name: Restore the _build cache
       uses: actions/cache@v3
       id: build-cache
       with:
+        key: ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-${{ env.MIX_ENV }}-build
+        restore-keys: ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-${{ env.MIX_ENV }}-build
         path: _build
-        key: ${{ runner.os }}-${{ env.ELIXIR_VERSION }}-${{ env.OTP_VERSION }}-${{ env.MIX_ENV }}-build-mixlockhash-${{ hashFiles(format('{0}{1}', github.workspace, '/mix.lock')) }}
-        restore-keys: |
-          ${{ runner.os }}-${{ env.ELIXIR_VERSION }}-${{ env.OTP_VERSION }}-${{ env.MIX_ENV }}-build-
 
     - name: Fetch mix dependencies
       if: steps.deps-cache.outputs.cache-hit != 'true'
diff --git a/.github/workflows/compatibility.yml b/.github/workflows/compatibility.yml
index 785cda2..bd83323 100644
--- a/.github/workflows/compatibility.yml
+++ b/.github/workflows/compatibility.yml
@@ -9,11 +9,6 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        beam:
-        - elixir: "1.7.4"
-          otp: "21.3"
-        - elixir: "1.12.3"
-          otp: "24.0"
         eventstore:
         - 20.10.2
         - 22.6.0
@@ -21,10 +16,9 @@ jobs:
       MIX_ENV: test
       EVENTSTORE_HOST: localhost
       EVENTSTORE_VERSION: ${{ matrix.eventstore }}
-
     steps:
     - name: Checkout
-      uses: actions/checkout@v2
+      uses: actions/checkout@v3
 
     - name: Set the EventStoreDB version
       run: sed -i 's|ghcr.io/eventstore/eventstore:ci|eventstore/eventstore:${{ matrix.eventstore }}-buster-slim|g' docker-compose.yml
@@ -34,27 +28,26 @@ jobs:
 
     - name: Setup Elixir and Erlang versions
       uses: erlef/setup-beam@v1
+      id: beam
       with:
-        otp-version: ${{ matrix.beam.otp }}
-        elixir-version: ${{ matrix.beam.elixir }}
+        version-file: .tool-versions
+        version-type: strict
 
     - name: Restore the deps cache
-      uses: actions/cache@v1
+      uses: actions/cache@v3
       id: deps-cache
       with:
+        key: ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-deps
+        restore-keys: ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-deps
         path: deps
-        key: ${{ runner.os }}-${{ matrix.beam.elixir }}-${{ matrix.beam.otp }}-${{ env.MIX_ENV }}-deps-mixlockhash-${{ hashFiles(format('{0}{1}', github.workspace, '/mix.lock')) }}
-        restore-keys: |
-          ${{ runner.os }}-${{ matrix.beam.elixir }}-${{ matrix.beam.otp }}-${{ env.MIX_ENV }}-deps-
 
     - name: Restore the _build cache
-      uses: actions/cache@v1
+      uses: actions/cache@v3
       id: build-cache
       with:
+        key: ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-${{ env.MIX_ENV }}-build
+        restore-keys: ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-${{ env.MIX_ENV }}-build
         path: _build
-        key: ${{ runner.os }}-${{ matrix.beam.elixir  }}-${{ matrix.beam.otp }}-${{ env.MIX_ENV }}-build-mixlockhash-${{ hashFiles(format('{0}{1}', github.workspace, '/mix.lock')) }}
-        restore-keys: |
-          ${{ runner.os }}-${{ matrix.beam.elixir }}-${{ matrix.beam.otp }}-${{ env.MIX_ENV }}-build-
 
     - name: Fetch mix dependencies
       if: steps.deps-cache.outputs.cache-hit != 'true'
@@ -72,6 +65,3 @@ jobs:
 
     - name: Run tests
       run: mix test --exclude version_incompatible
-
-    - name: Credo
-      run: mix credo
diff --git a/.github/workflows/refresh-dev-cache.yml b/.github/workflows/refresh-dev-cache.yml
index 06fafeb..de30c11 100644
--- a/.github/workflows/refresh-dev-cache.yml
+++ b/.github/workflows/refresh-dev-cache.yml
@@ -37,19 +37,14 @@ jobs:
 
     steps:
     - name: Checkout
-      uses: actions/checkout@v2
-
-    - name: Determine the elixir version
-      run: echo "ELIXIR_VERSION=$(grep -h elixir .tool-versions | awk '{ print $2 }' | awk -F - '{print $1}')" >> $GITHUB_ENV
-
-    - name: Determine the otp version
-      run: echo "OTP_VERSION=$(grep -h erlang .tool-versions | awk '{ print $2 }')" >> $GITHUB_ENV
+      uses: actions/checkout@v3
 
     - name: Setup Elixir and Erlang versions
-      uses: erlef/setup-beam@v1.7.0
+      uses: erlef/setup-beam@v1
+      id: beam
       with:
-        otp-version: ${{ env.OTP_VERSION }}
-        elixir-version: ${{ env.ELIXIR_VERSION }}
+        version-file: .tool-versions
+        version-type: strict
 
     - name: Restore the deps cache
       uses: actions/cache@v1
diff --git a/.gitignore b/.gitignore
index e89b9eb..00a75bf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -22,6 +22,8 @@ erl_crash.dump
 # Ignore package tarball (built via "mix hex.build").
 spear-*.tar
 
-
 # Temporary files for e.g. tests
 /tmp
+
+/priv/plts/*.plt
+/priv/plts/*.plt.hash
diff --git a/.tool-versions b/.tool-versions
index 93a429b..f08de31 100644
--- a/.tool-versions
+++ b/.tool-versions
@@ -1,2 +1,2 @@
-elixir 1.12.3-otp-24
-erlang 24.0
+elixir 1.14.5-otp-26
+erlang 26.0
diff --git a/config/config.exs b/config/config.exs
index 8233fe9..983b681 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -1,3 +1,13 @@
-use Mix.Config
+import Config
 
-import_config "#{Mix.env()}.exs"
+config :spear, Spear.Test.ClientFixture, connection_string: "esdb://localhost:2113"
+
+host = System.get_env("EVENTSTORE_HOST") || "localhost"
+
+config :spear, :config,
+  connection_string: "esdb://admin:changeit@#{host}:2113?tls=true",
+  mint_opts: [
+    transport_opts: [
+      cacertfile: Path.join([__DIR__ | ~w(.. eventstoredb certs ca ca.crt)])
+    ]
+  ]
diff --git a/config/dev.exs b/config/dev.exs
deleted file mode 100644
index d2d855e..0000000
--- a/config/dev.exs
+++ /dev/null
@@ -1 +0,0 @@
-use Mix.Config
diff --git a/config/prod.exs b/config/prod.exs
deleted file mode 100644
index d2d855e..0000000
--- a/config/prod.exs
+++ /dev/null
@@ -1 +0,0 @@
-use Mix.Config
diff --git a/config/test.exs b/config/test.exs
deleted file mode 100644
index 0000cfb..0000000
--- a/config/test.exs
+++ /dev/null
@@ -1,13 +0,0 @@
-use Mix.Config
-
-config :spear, Spear.Test.ClientFixture, connection_string: "esdb://localhost:2113"
-
-host = System.get_env("EVENTSTORE_HOST") || "localhost"
-
-config :spear, :config,
-  connection_string: "esdb://admin:changeit@#{host}:2113?tls=true",
-  mint_opts: [
-    transport_opts: [
-      cacertfile: Path.join([__DIR__ | ~w(.. eventstoredb certs ca ca.crt)])
-    ]
-  ]
diff --git a/docker-compose.yml b/docker-compose.yml
index ce77b54..bda3fb6 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -13,7 +13,7 @@ services:
     # messages via wireshark
     # command: "--insecure --run-projections=All"
     ports:
-    - 2113:2113
+    - '2113:2113'
 
   app:
     image: elixir:1.12.2
diff --git a/lib/spear.ex b/lib/spear.ex
index 34a21fa..faaa60b 100644
--- a/lib/spear.ex
+++ b/lib/spear.ex
@@ -1993,7 +1993,7 @@ defmodule Spear do
           stream_name :: String.t() | :all,
           group_name :: String.t(),
           opts :: Keyword.t()
-        ) :: {:ok, Spear.PersistentSubcription.Info.t()} | {:error, any()}
+        ) :: {:ok, Spear.PersistentSubscription.Info.t()} | {:error, any()}
   def get_persistent_subscription_info(conn, stream_name, group_name, opts \\ [])
       when (is_binary(stream_name) or stream_name == :all) and is_binary(group_name) do
     get_info_message =
diff --git a/lib/spear/connection.ex b/lib/spear/connection.ex
index 03d6efc..707cb2b 100644
--- a/lib/spear/connection.ex
+++ b/lib/spear/connection.ex
@@ -88,6 +88,8 @@ defmodule Spear.Connection do
 
   defstruct [:config, :conn, requests: %{}, keep_alive_timer: %KeepAliveTimer{}]
 
+  @type state :: %__MODULE__{}
+
   @typedoc """
   A connection process
 
@@ -152,9 +154,7 @@ defmodule Spear.Connection do
 
       %Config{errors: errors} ->
         error_lines =
-          errors
-          |> Enum.map(fn {key, error} -> "\t#{inspect(key)}: #{error}" end)
-          |> Enum.join("\n")
+          Enum.map_join(errors, "\n", fn {key, error} -> "\t#{inspect(key)}: #{error}" end)
 
         Logger.error("""
         Invalid configuration passed to #{inspect(__MODULE__)}. Found the following errors:
@@ -327,10 +327,10 @@ defmodule Spear.Connection do
   def handle_info(:keep_alive_expired, s), do: {:disconnect, :keep_alive_timeout, s}
 
   def handle_info(message, s) do
-    with %Mint.HTTP2{} = conn <- s.conn,
-         {:ok, conn, responses} <- Mint.HTTP2.stream(conn, message) do
-      {:noreply, put_in(s.conn, conn) |> handle_responses(responses)}
-    else
+    case Mint.HTTP2.stream(s.conn, message) do
+      {:ok, conn, responses} ->
+        {:noreply, put_in(s.conn, conn) |> handle_responses(responses)}
+
       # coveralls-ignore-start
       {:error, conn, reason, responses} ->
         s = put_in(s.conn, conn) |> handle_responses(responses)
diff --git a/lib/spear/connection/request.ex b/lib/spear/connection/request.ex
index e2a3622..024aa5f 100644
--- a/lib/spear/connection/request.ex
+++ b/lib/spear/connection/request.ex
@@ -77,8 +77,8 @@ defmodule Spear.Connection.Request do
      {[{message, message_size} | message_buffer], message_size + message_buffer_size, max_size}}
   end
 
-  @spec emit_messages(%Spear.Connection{}, %__MODULE__{}) ::
-          {:ok, %Spear.Connection{}} | {:error, %Spear.Connection{}, reason :: any()}
+  @spec emit_messages(Spear.Connection.state(), %__MODULE__{}) ::
+          {:ok, Spear.Connection.state()} | {:error, Spear.Connection.state(), reason :: any()}
   def emit_messages(state, %__MODULE__{status: :done, buffer: <<>>}), do: {:ok, state}
 
   def emit_messages(state, %__MODULE__{status: :done, buffer: buffer} = request) do
diff --git a/lib/spear/connection/response.ex b/lib/spear/connection/response.ex
index 2aa4ba1..9b14880 100644
--- a/lib/spear/connection/response.ex
+++ b/lib/spear/connection/response.ex
@@ -3,5 +3,12 @@ defmodule Spear.Connection.Response do
 
   # a slim data structure for storing information about an HTTP/2 response
 
+  @type t :: %__MODULE__{
+          status: Mint.Types.status(),
+          type: {module(), atom()},
+          headers: Mint.Types.headers(),
+          data: binary()
+        }
+
   defstruct [:status, :type, headers: [], data: <<>>]
 end
diff --git a/lib/spear/reading/stream.ex b/lib/spear/reading/stream.ex
index 3bd4eb2..ce9e32a 100644
--- a/lib/spear/reading/stream.ex
+++ b/lib/spear/reading/stream.ex
@@ -82,7 +82,7 @@ defmodule Spear.Reading.Stream do
     response
   end
 
-  @spec unfold_chunk(binary()) :: {struct(), binary()} | nil
+  @spec unfold_chunk(binary()) :: {tuple(), binary()} | nil
   def unfold_chunk(buffer) when is_binary(buffer) do
     Spear.Grpc.decode_next_message(
       buffer,
diff --git a/mix.exs b/mix.exs
index 5c37f2c..872bd51 100644
--- a/mix.exs
+++ b/mix.exs
@@ -25,14 +25,18 @@ defmodule Spear.MixProject do
         inch: :dev,
         bless: :test,
         test: :test,
-        dialyzer: :test
+        dialyzer: :dev
       ],
       name: "Spear",
       source_url: @source_url,
       deps: deps(),
       docs: docs(),
       package: package(),
-      description: description()
+      description: description(),
+      dialyzer: [
+        plt_add_apps: [:jason],
+        plt_file: {:no_warn, "priv/plts/dialyzer.plt"}
+      ]
     ]
   end
 
@@ -50,14 +54,16 @@ defmodule Spear.MixProject do
       {:event_store_db_gpb_protobufs, "~> 2.2"},
       {:connection, "~> 1.0"},
       # optional dependencies
-      {:jason, ">= 0.0.0", optional: true},
+      {:jason, "~> 1.0", optional: true},
+
       # dev/test utilities
       {:castore, ">= 0.0.0", only: [:dev, :test]},
-      {:ex_doc, "~> 0.24", only: :dev, runtime: false},
+      {:ex_doc, ">= 0.0.0", only: :dev, runtime: false},
+      {:dialyxir, ">= 0.0.0", only: [:dev, :test], runtime: false},
       # testing suite
-      {:credo, "~> 1.5", only: :test},
+      {:credo, ">= 0.0.0", only: :test},
       {:bless, "~> 1.0", only: :test},
-      {:excoveralls, "~> 0.7", only: :test}
+      {:excoveralls, ">= 0.0.0", only: :test}
     ]
   end
 
diff --git a/mix.lock b/mix.lock
index 99a4246..7db756a 100644
--- a/mix.lock
+++ b/mix.lock
@@ -1,26 +1,28 @@
 %{
   "bless": {:hex, :bless, "1.1.0", "b27571e49a4ba22d92412184740b186448a27c3ddf2e9e687851e937932b5a60", [:mix], [], "hexpm", "ea5dc19a36609f927d4035a8409393cd3016b5c482245cffa30b3bd6669c617e"},
-  "bunt": {:hex, :bunt, "0.2.0", "951c6e801e8b1d2cbe58ebbd3e616a869061ddadcc4863d0a2182541acae9a38", [:mix], [], "hexpm", "7af5c7e09fe1d40f76c8e4f9dd2be7cebd83909f31fee7cd0e9eadc567da8353"},
-  "castore": {:hex, :castore, "0.1.10", "b01a007416a0ae4188e70b3b306236021b16c11474038ead7aff79dd75538c23", [:mix], [], "hexpm", "a48314e0cb45682db2ea27b8ebfa11bd6fa0a6e21a65e5772ad83ca136ff2665"},
-  "certifi": {:hex, :certifi, "2.6.1", "dbab8e5e155a0763eea978c913ca280a6b544bfa115633fa20249c3d396d9493", [:rebar3], [], "hexpm", "524c97b4991b3849dd5c17a631223896272c6b0af446778ba4675a1dff53bb7e"},
+  "bunt": {:hex, :bunt, "0.2.1", "e2d4792f7bc0ced7583ab54922808919518d0e57ee162901a16a1b6664ef3b14", [:mix], [], "hexpm", "a330bfb4245239787b15005e66ae6845c9cd524a288f0d141c148b02603777a5"},
+  "castore": {:hex, :castore, "0.1.22", "4127549e411bedd012ca3a308dede574f43819fe9394254ca55ab4895abfa1a2", [:mix], [], "hexpm", "c17576df47eb5aa1ee40cc4134316a99f5cad3e215d5c77b8dd3cfef12a22cac"},
+  "certifi": {:hex, :certifi, "2.9.0", "6f2a475689dd47f19fb74334859d460a2dc4e3252a3324bd2111b8f0429e7e21", [:rebar3], [], "hexpm", "266da46bdb06d6c6d35fde799bcb28d36d985d424ad7c08b5bb48f5b5cdd4641"},
   "connection": {:hex, :connection, "1.1.0", "ff2a49c4b75b6fb3e674bfc5536451607270aac754ffd1bdfe175abe4a6d7a68", [:mix], [], "hexpm", "722c1eb0a418fbe91ba7bd59a47e28008a189d47e37e0e7bb85585a016b2869c"},
-  "credo": {:hex, :credo, "1.5.6", "e04cc0fdc236fefbb578e0c04bd01a471081616e741d386909e527ac146016c6", [:mix], [{:bunt, "~> 0.2.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:file_system, "~> 0.2.8", [hex: :file_system, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "4b52a3e558bd64e30de62a648518a5ea2b6e3e5d2b164ef5296244753fc7eb17"},
-  "earmark_parser": {:hex, :earmark_parser, "1.4.29", "149d50dcb3a93d9f3d6f3ecf18c918fb5a2d3c001b5d3305c926cddfbd33355b", [:mix], [], "hexpm", "4902af1b3eb139016aed210888748db8070b8125c2342ce3dcae4f38dcc63503"},
+  "credo": {:hex, :credo, "1.7.0", "6119bee47272e85995598ee04f2ebbed3e947678dee048d10b5feca139435f75", [:mix], [{:bunt, "~> 0.2.1", [hex: :bunt, repo: "hexpm", optional: false]}, {:file_system, "~> 0.2.8", [hex: :file_system, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "6839fcf63d1f0d1c0f450abc8564a57c43d644077ab96f2934563e68b8a769d7"},
+  "dialyxir": {:hex, :dialyxir, "1.3.0", "fd1672f0922b7648ff9ce7b1b26fcf0ef56dda964a459892ad15f6b4410b5284", [:mix], [{:erlex, ">= 0.2.6", [hex: :erlex, repo: "hexpm", optional: false]}], "hexpm", "00b2a4bcd6aa8db9dcb0b38c1225b7277dca9bc370b6438715667071a304696f"},
+  "earmark_parser": {:hex, :earmark_parser, "1.4.32", "fa739a0ecfa34493de19426681b23f6814573faee95dfd4b4aafe15a7b5b32c6", [:mix], [], "hexpm", "b8b0dd77d60373e77a3d7e8afa598f325e49e8663a51bcc2b88ef41838cca755"},
+  "erlex": {:hex, :erlex, "0.2.6", "c7987d15e899c7a2f34f5420d2a2ea0d659682c06ac607572df55a43753aa12e", [:mix], [], "hexpm", "2ed2e25711feb44d52b17d2780eabf998452f6efda104877a3881c2f8c0c0c75"},
   "event_store_db_gpb_protobufs": {:hex, :event_store_db_gpb_protobufs, "2.2.0", "fca2bdeac5fca205e02d3cb9f170477a5422e147413d21d07c19e1ffc70e66aa", [:rebar3], [{:gpb, "~> 4.0", [hex: :gpb, repo: "hexpm", optional: false]}], "hexpm", "dad49149eb6913805277a698ec1f607aac945c40cbf427aa03cc97309fdf2f1f"},
-  "ex_doc": {:hex, :ex_doc, "0.29.0", "4a1cb903ce746aceef9c1f9ae8a6c12b742a5461e6959b9d3b24d813ffbea146", [:mix], [{:earmark_parser, "~> 1.4.19", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "f096adb8bbca677d35d278223361c7792d496b3fc0d0224c9d4bc2f651af5db1"},
-  "excoveralls": {:hex, :excoveralls, "0.14.1", "14140e4ef343f2af2de33d35268c77bc7983d7824cb945e6c2af54235bc2e61f", [:mix], [{:hackney, "~> 1.16", [hex: :hackney, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "4a588f9f8cf9dc140cc1f3d0ea4d849b2f76d5d8bee66b73c304bb3d3689c8b0"},
+  "ex_doc": {:hex, :ex_doc, "0.29.4", "6257ecbb20c7396b1fe5accd55b7b0d23f44b6aa18017b415cb4c2b91d997729", [:mix], [{:earmark_parser, "~> 1.4.31", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "2c6699a737ae46cb61e4ed012af931b57b699643b24dabe2400a8168414bc4f5"},
+  "excoveralls": {:hex, :excoveralls, "0.16.1", "0bd42ed05c7d2f4d180331a20113ec537be509da31fed5c8f7047ce59ee5a7c5", [:mix], [{:hackney, "~> 1.16", [hex: :hackney, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "dae763468e2008cf7075a64cb1249c97cb4bc71e236c5c2b5e5cdf1cfa2bf138"},
   "file_system": {:hex, :file_system, "0.2.10", "fb082005a9cd1711c05b5248710f8826b02d7d1784e7c3451f9c1231d4fc162d", [:mix], [], "hexpm", "41195edbfb562a593726eda3b3e8b103a309b733ad25f3d642ba49696bf715dc"},
   "gpb": {:hex, :gpb, "4.19.5", "ff9d434308fd205c07b662a86c37e9579a8c9a04ad511d2c4dd63430a59f4729", [:make, :rebar3], [], "hexpm", "21b76750d66b459ce40cb14298fb38ef8e0161d9b672a5284585c02563806f8e"},
-  "hackney": {:hex, :hackney, "1.17.4", "99da4674592504d3fb0cfef0db84c3ba02b4508bae2dff8c0108baa0d6e0977c", [:rebar3], [{:certifi, "~>2.6.1", [hex: :certifi, repo: "hexpm", optional: false]}, {:idna, "~>6.1.0", [hex: :idna, repo: "hexpm", optional: false]}, {:metrics, "~>1.0.0", [hex: :metrics, repo: "hexpm", optional: false]}, {:mimerl, "~>1.1", [hex: :mimerl, repo: "hexpm", optional: false]}, {:parse_trans, "3.3.1", [hex: :parse_trans, repo: "hexpm", optional: false]}, {:ssl_verify_fun, "~>1.1.0", [hex: :ssl_verify_fun, repo: "hexpm", optional: false]}, {:unicode_util_compat, "~>0.7.0", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm", "de16ff4996556c8548d512f4dbe22dd58a587bf3332e7fd362430a7ef3986b16"},
+  "hackney": {:hex, :hackney, "1.18.1", "f48bf88f521f2a229fc7bae88cf4f85adc9cd9bcf23b5dc8eb6a1788c662c4f6", [:rebar3], [{:certifi, "~> 2.9.0", [hex: :certifi, repo: "hexpm", optional: false]}, {:idna, "~> 6.1.0", [hex: :idna, repo: "hexpm", optional: false]}, {:metrics, "~> 1.0.0", [hex: :metrics, repo: "hexpm", optional: false]}, {:mimerl, "~> 1.1", [hex: :mimerl, repo: "hexpm", optional: false]}, {:parse_trans, "3.3.1", [hex: :parse_trans, repo: "hexpm", optional: false]}, {:ssl_verify_fun, "~> 1.1.0", [hex: :ssl_verify_fun, repo: "hexpm", optional: false]}, {:unicode_util_compat, "~> 0.7.0", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm", "a4ecdaff44297e9b5894ae499e9a070ea1888c84afdd1fd9b7b2bc384950128e"},
   "idna": {:hex, :idna, "6.1.1", "8a63070e9f7d0c62eb9d9fcb360a7de382448200fbbd1b106cc96d3d8099df8d", [:rebar3], [{:unicode_util_compat, "~>0.7.0", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm", "92376eb7894412ed19ac475e4a86f7b413c1b9fbb5bd16dccd57934157944cea"},
-  "jason": {:hex, :jason, "1.2.2", "ba43e3f2709fd1aa1dce90aaabfd039d000469c05c56f0b8e31978e03fa39052", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "18a228f5f0058ee183f29f9eae0805c6e59d61c3b006760668d8d18ff0d12179"},
+  "jason": {:hex, :jason, "1.4.0", "e855647bc964a44e2f67df589ccf49105ae039d4179db7f6271dfd3843dc27e6", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "79a3791085b2a0f743ca04cec0f7be26443738779d09302e01318f97bdb82121"},
   "makeup": {:hex, :makeup, "1.1.0", "6b67c8bc2882a6b6a445859952a602afc1a41c2e08379ca057c0f525366fc3ca", [:mix], [{:nimble_parsec, "~> 1.2.2 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "0a45ed501f4a8897f580eabf99a2e5234ea3e75a4373c8a52824f6e873be57a6"},
-  "makeup_elixir": {:hex, :makeup_elixir, "0.16.0", "f8c570a0d33f8039513fbccaf7108c5d750f47d8defd44088371191b76492b0b", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.2.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "28b2cbdc13960a46ae9a8858c4bebdec3c9a6d7b4b9e7f4ed1502f8159f338e7"},
+  "makeup_elixir": {:hex, :makeup_elixir, "0.16.1", "cc9e3ca312f1cfeccc572b37a09980287e243648108384b97ff2b76e505c3555", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.2.3 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "e127a341ad1b209bd80f7bd1620a15693a9908ed780c3b763bccf7d200c767c6"},
   "makeup_erlang": {:hex, :makeup_erlang, "0.1.1", "3fcb7f09eb9d98dc4d208f49cc955a34218fc41ff6b84df7c75b3e6e533cc65f", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "174d0809e98a4ef0b3309256cbf97101c6ec01c4ab0b23e926a9e17df2077cbb"},
   "metrics": {:hex, :metrics, "1.0.1", "25f094dea2cda98213cecc3aeff09e940299d950904393b2a29d191c346a8486", [:rebar3], [], "hexpm", "69b09adddc4f74a40716ae54d140f93beb0fb8978d8636eaded0c31b6f099f16"},
   "mimerl": {:hex, :mimerl, "1.2.0", "67e2d3f571088d5cfd3e550c383094b47159f3eee8ffa08e64106cdf5e981be3", [:rebar3], [], "hexpm", "f278585650aa581986264638ebf698f8bb19df297f66ad91b18910dfc6e19323"},
   "mint": {:hex, :mint, "1.3.0", "396b3301102f7b775e103da5a20494b25753aed818d6d6f0ad222a3a018c3600", [:mix], [{:castore, "~> 0.1.0", [hex: :castore, repo: "hexpm", optional: true]}], "hexpm", "a9aac960562e43ca69a77e5176576abfa78b8398cec5543dd4fb4ab0131d5c1e"},
-  "nimble_parsec": {:hex, :nimble_parsec, "1.2.3", "244836e6e3f1200c7f30cb56733fd808744eca61fd182f731eac4af635cc6d0b", [:mix], [], "hexpm", "c8d789e39b9131acf7b99291e93dae60ab48ef14a7ee9d58c6964f59efb570b0"},
+  "nimble_parsec": {:hex, :nimble_parsec, "1.3.1", "2c54013ecf170e249e9291ed0a62e5832f70a476c61da16f6aac6dca0189f2af", [:mix], [], "hexpm", "2682e3c0b2eb58d90c6375fc0cc30bc7be06f365bf72608804fb9cffa5e1b167"},
   "parse_trans": {:hex, :parse_trans, "3.3.1", "16328ab840cc09919bd10dab29e431da3af9e9e7e7e6f0089dd5a2d2820011d8", [:rebar3], [], "hexpm", "07cd9577885f56362d414e8c4c4e6bdf10d43a8767abb92d24cbe8b24c54888b"},
   "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.6", "cf344f5692c82d2cd7554f5ec8fd961548d4fd09e7d22f5b62482e5aeaebd4b0", [:make, :mix, :rebar3], [], "hexpm", "bdb0d2471f453c88ff3908e7686f86f9be327d065cc1ec16fa4540197ea04680"},
   "unicode_util_compat": {:hex, :unicode_util_compat, "0.7.0", "bc84380c9ab48177092f43ac89e4dfa2c6d62b40b8bd132b1059ecc7232f9a78", [:rebar3], [], "hexpm", "25eee6d67df61960cf6a794239566599b09e17e668d3700247bc498638152521"},
diff --git a/priv/plts/.gitignore b/priv/plts/.gitignore
new file mode 100644
index 0000000..72e8ffc
--- /dev/null
+++ b/priv/plts/.gitignore
@@ -0,0 +1 @@
+*
diff --git a/test/spear/connection_test.exs b/test/spear/connection_test.exs
index 018cd88..d02fe63 100644
--- a/test/spear/connection_test.exs
+++ b/test/spear/connection_test.exs
@@ -3,7 +3,11 @@ defmodule Spear.ConnectionTest do
 
   import ExUnit.CaptureLog
 
-  @good_config Application.fetch_env!(:spear, :config)
+  @good_config Application.compile_env!(:spear, :config)
+
+  defmodule MfaTest do
+    def send_me(pid), do: send(pid, :mfa_invoked)
+  end
 
   describe "given a connection_string leading nowhere" do
     setup do
@@ -77,14 +81,8 @@ defmodule Spear.ConnectionTest do
   end
 
   test "a connection started with a :on_connect MFA invokes it at each connection" do
-    defmodule MfaTest do
-      def send_me(pid), do: send(pid, :mfa_invoked)
-    end
-
     my_pid = self()
-
     config = [{:on_connect, {MfaTest, :send_me, [my_pid]}} | @good_config]
-
     conn = start_supervised!({Spear.Connection, config})
 
     assert_receive(:mfa_invoked)
@@ -94,14 +92,8 @@ defmodule Spear.ConnectionTest do
   end
 
   test "a connection started with a :on_disconnect MFA invokes it at each disconnection" do
-    defmodule MfaTest do
-      def send_me(pid), do: send(pid, :mfa_invoked)
-    end
-
     my_pid = self()
-
     config = [{:on_disconnect, {MfaTest, :send_me, [my_pid]}} | @good_config]
-
     conn = start_supervised!({Spear.Connection, config})
 
     assert Connection.call(conn, :close) == {:ok, :closed}
diff --git a/test/spear_test.exs b/test/spear_test.exs
index 9bd148c..a8b9523 100644
--- a/test/spear_test.exs
+++ b/test/spear_test.exs
@@ -10,7 +10,7 @@ defmodule SpearTest do
   @max_append_bytes 1_048_576
   @checkpoint_after 32 * 32 * 32
 
-  @config Application.fetch_env!(:spear, :config)
+  @config Application.compile_env!(:spear, :config)
 
   setup do
     conn = start_supervised!({Spear.Connection, @config})