Run dialyzer in CI

This runs as its own job because it requires the 'dev' build
environment.

.github/workflows/ci.yml

@@ -25,8 +25,50 @@ jobs:
         run: mix deps.get
       - name: Check format
         run: mix format --check-formatted
+  dialyzer:
+    name: Dialyzer
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        otp: [22.2]
+        elixir: [1.11]
+    env:
+      MIX_ENV: dev
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions/setup-elixir@v1
+        with:
+          otp-version: ${{ matrix.otp }}
+          elixir-version: ${{ matrix.elixir }}
+      - name: Set up dependency cache
+        uses: actions/cache@v1
+        with:
+          path: deps/
+          key: ${{ runner.os }}-${{ matrix.otp }}-${{ matrix.elixir }}-deps-${{ hashFiles('**/mix.lock') }}
+          restore-keys: ${{ runner.os }}-${{ matrix.otp }}-${{ matrix.elixir }}-deps-
+      - name: Set up build cache
+        uses: actions/cache@v1
+        with:
+          path: _build/test/
+          key: ${{ runner.os }}-${{ matrix.otp }}-${{ matrix.elixir }}-build-${{ hashFiles('**/mix.lock') }}
+          restore-keys: ${{ runner.os }}-${{ matrix.otp }}-${{ matrix.elixir }}-build-
+      - name: Set up PLT cache
+        uses: actions/cache@v1
+        with:
+          path: priv/plts/
+          key: ${{ runner.os }}-${{ matrix.otp }}-${{ matrix.elixir }}-plt-${{ hashFiles('**/mix.lock') }}
+          restore-keys: ${{ runner.os }}-${{ matrix.otp }}-${{ matrix.elixir }}-plt-
+      - name: Install dependencies
+        run: mix deps.get --only dev
+      - name: Compile
+        run: |
+          mix deps.compile
+          mix compile
+      - name: Run dialyzer
+        run: mix dialyzer
   test:
-    name: OTP ${{ matrix.otp }} / Elixir ${{ matrix.elixir }}
+    name: Test OTP ${{ matrix.otp }} / Elixir ${{ matrix.elixir }}
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false

.gitignore

@@ -2,6 +2,7 @@
 /deps
 /doc
 /log
+/priv/plts
 erl_crash.dump
 *.ez
 data.*

mix.exs

@@ -28,7 +28,7 @@ defmodule Elixometer.Mixfile do
       elixirc_paths: elixirc_paths(Mix.env()),
 
       # Dialyzer
-      dialyzer: [plt_add_deps: :transitive],
+      dialyzer: [plt_add_deps: :transitive, plt_file: {:no_warn, "priv/plts/dialyzer.plt"}],
 
       # Docs
       name: "Elixometer",
@@ -62,7 +62,7 @@ defmodule Elixometer.Mixfile do
       # https://github.com/basho/lager/pull/321
       {:lager, ">= 3.2.1"},
       {:exometer_core, "~> 1.5"},
-      {:dialyxir, "~> 1.0", only: :dev, runtime: false},
+      {:dialyxir, "~> 1.1.0", only: :dev, runtime: false},
       {:ex_doc, "~> 0.20", only: :dev},
       {:excoveralls, "~> 0.12", only: [:dev, :test]},
       {:pobox, "~> 1.2"}