CI: add GitHub workflows and tests for stack builds

Author: tarleb

.github/workflows/ci.yml

@@ -0,0 +1,56 @@
+name: CI
+
+# Trigger the workflow on push or pull request, but only for the
+# master branch
+on:
+  pull_request:
+  push:
+    branches: [master]
+
+jobs:
+  build:
+    name: ghc ${{ matrix.versions.ghc }}
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        versions:
+          - ghc: '8.0.2'
+            cabal: '2.4'
+          - ghc: '8.2.2'
+            cabal: '2.4'
+          - ghc: '8.4.4'
+            cabal: '2.4'
+          - ghc: '8.6.5'
+            cabal: '3.2'
+          - ghc: '8.8.3'
+            cabal: '3.2'
+          - ghc: '8.10.1'
+            cabal: '3.2'
+
+    steps:
+    - uses: actions/checkout@v2
+      if: >-
+        github.event.action == 'opened' ||
+        github.event.action == 'synchronize' ||
+        github.event.ref == 'refs/heads/master'
+
+    - uses: actions/setup-haskell@v1
+      name: Setup Haskell
+      with:
+        ghc-version: ${{ matrix.versions.ghc }}
+        cabal-version: ${{ matrix.versions.cabal }}
+
+    - uses: actions/cache@v1
+      name: Cache ~/.cabal/store
+      with:
+        path: ~/.cabal/store
+        key: ${{ runner.os }}-${{ matrix.versions.ghc }}-cabal
+
+    - name: Build
+      run: |
+        cabal v2-update
+        cabal v2-build --enable-tests
+
+    - name: Test
+      run: |
+        cabal v2-test --enable-tests

.travis.yml

@@ -1,14 +1,28 @@
-sudo: false
+sudo: true
 language: haskell
 
-# Speed builds up by caching install requirements
+git:
+  depth: 5
+
+cabal: "2.4"
+
 cache:
   directories:
-  - $HOME/.ghc
-  - $HOME/.cabal
-
-ghc:
-  - '8.0'
-  - '8.2'
-  - '8.4'
-  - '8.6'
+  - "$HOME/.cabal/store"
+  - "$HOME/.stack"
+  - "$TRAVIS_BUILD_DIR/.stack-work"
+
+install:
+  # HLint check
+  - curl -sSL https://raw.github.com/ndmitchell/neil/master/misc/travis.sh | sh -s -- hlint .
+
+  - |
+    curl -sSL https://get.haskellstack.org/ | sh
+    stack --version
+    stack build \
+          --test \
+          --no-run-tests \
+          --ghc-options=-Werror
+
+script:
+  - stack test