Migrate CI to GitHub Actions

Fixes #70.

Co-authored-by: Ryan Scott <ryan.gl.scott@gmail.com>

.github/workflows/build.yml

@@ -0,0 +1,86 @@
+name: build
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  build:
+    name: ${{ matrix.os }} / GHC ${{ matrix.ghc }}
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      matrix:
+        os:
+          - ubuntu-16.04 # https://launchpad.net/~hvr/+archive/ubuntu/ghc?field.series_filter=xenial
+        ghc:
+          - 7.0.4
+          - 7.2.2
+          - 7.4.2
+          - 7.6.3
+          - 7.8.4
+          - 7.10.3
+          - 8.0.2
+          - 8.2.2
+          - 8.4.4
+          - 8.6.5
+          - 8.8.4
+          - 8.10.4
+          - 9.0.1
+    steps:
+      - uses: actions/checkout@v2
+      - uses: haskell/actions/setup@v1
+        with:
+          ghc-version: ${{ matrix.ghc }}
+
+      - name: install typediff
+        run: |
+          mkdir -p "$HOME/.local/bin"
+          curl -L https://github.com/haskell-compat/base-compat/releases/download/typediff-0.1.4/typediff > "$HOME/.local/bin/typediff"
+          chmod a+x "$HOME/.local/bin/typediff"
+          echo "$HOME/.local/bin" >> "$GITHUB_PATH"
+
+      - run: cabal update
+
+      - name: cabal configure
+        run: |
+          cabal configure --enable-tests ${{ env.enable_documentation }}
+          echo -e "$EXTRAS" >> cabal.project.local
+        env:
+          EXTRAS: |
+            package base-compat
+              ghc-options: -Werror
+            package base-compat-batteries
+              ghc-options: -Werror
+            package type-check
+              ghc-options: -Werror
+
+      - run: cabal build all
+      - run: cabal test all --test-show-details=direct
+        env:
+          HSPEC_OPTIONS: --color
+      - run: cabal haddock all
+        # Old versions of Haddock have trouble building the documentation for
+        # base-compat-batteries' Data.Type.Equality.Compat module:
+        #
+        # * GHC 7.2.2 runs into "synifyType: PredTys are not, in themselves, source-level types."
+        #   This bug is apparently so obscure that no issue was ever filed about it!
+        #
+        # * GHC 7.6 runs into https://github.com/haskell/haddock/issues/242
+        if: matrix.ghc != '7.2.2' && matrix.ghc != '7.6.3'
+
+      - run: cd base-compat && cabal check
+      - run: cd base-compat-batteries && cabal check
+
+  success:
+    needs: build
+    runs-on: ubuntu-latest
+    if: always() # this is required as GitHub considers "skipped" jobs as "passed" when checking branch protection rules
+
+    steps:
+      - run: false
+        if: needs.build.result != 'success'

base-compat-batteries/base-compat-batteries.cabal

@@ -34,18 +34,6 @@ description:      Provides functions available in later versions of @base@ to
                   @<https://github.com/haskell-compat/base-compat/blob/master/base-compat/README.markdown#dependencies here>@
                   for a more comprehensive list of differences between
                   @base-compat@ and @base-compat-batteries@.
-tested-with:        GHC == 7.0.4
-                  , GHC == 7.2.2
-                  , GHC == 7.4.2
-                  , GHC == 7.6.3
-                  , GHC == 7.8.4
-                  , GHC == 7.10.3
-                  , GHC == 8.0.2
-                  , GHC == 8.2.2
-                  , GHC == 8.4.4
-                  , GHC == 8.6.5
-                  , GHC == 8.8.3
-                  , GHC == 8.10.1
 extra-source-files: CHANGES.markdown, README.markdown
 
 source-repository head

base-compat/base-compat.cabal

@@ -43,18 +43,6 @@ description:      Provides functions available in later versions of @base@ to
                   module with the suffix @.Repl@, which are distinct from
                   anything in @base-compat-batteries@, to allow for easier
                   use in GHCi.
-tested-with:        GHC == 7.0.4
-                  , GHC == 7.2.2
-                  , GHC == 7.4.2
-                  , GHC == 7.6.3
-                  , GHC == 7.8.4
-                  , GHC == 7.10.3
-                  , GHC == 8.0.2
-                  , GHC == 8.2.2
-                  , GHC == 8.4.4
-                  , GHC == 8.6.5
-                  , GHC == 8.8.3
-                  , GHC == 8.10.1
 extra-source-files: CHANGES.markdown, README.markdown
 
 source-repository head

check/type-check.cabal

@@ -28,18 +28,6 @@ extra-source-files:
   index/*.index
   types/*.types
 
-tested-with:        GHC == 7.0.4
-                  , GHC == 7.2.2
-                  , GHC == 7.4.2
-                  , GHC == 7.6.3
-                  , GHC == 7.8.4
-                  , GHC == 7.10.3
-                  , GHC == 8.0.2
-                  , GHC == 8.2.2
-                  , GHC == 8.4.4
-                  , GHC == 8.6.5
-                  , GHC == 8.8.3
-                  , GHC == 8.10.1
 library
   exposed-modules:
       TypeDump