Present code-coverage input in PRs

Author: MaximilianAlgehed

.github/workflows/haskell-ci.yml

@@ -1,5 +1,9 @@
 name: Haskell-CI
 
+permissions:
+  contents: read
+  pull-requests: write
+
 on:
   push:
     branches:
@@ -21,10 +25,9 @@ jobs:
     strategy:
       matrix:
         ghc-version: [latest, 9.12, "9.10", 9.8, 9.6]
-        os: [ubuntu-24.04]
       fail-fast: false
 
-    runs-on: ${{ matrix.os }}
+    runs-on: ubuntu-latest
 
     steps:
       - uses: actions/checkout@v4
@@ -33,13 +36,57 @@ jobs:
           ghc-version: ${{matrix.ghc-version}}
       - uses: actions/cache/restore@v4
         with:
-          key: ${{ matrix.os }}-${{ matrix.ghc-version }}-${{ github.sha }}
+          key: ${{ matrix.ghc-version }}-${{ github.sha }}
           path: ~/.cabal/store
-          restore-keys: ${{ matrix.os }}-${{ matrix.ghc-version }}-
-      - run: cabal build all
-      - run: cabal test all
+          restore-keys: ${{ matrix.ghc-version }}-
+      - run: cabal build all --ghc-options=-fhpc
+      - run: cabal test all --ghc-options=-fhpc
+      - run: ./scripts/generate-coverage-comment.sh constrained.tix > coverage-report.md
+      - run: cat coverage-report.md
       - run: cabal haddock all
       - uses: actions/cache/save@v4
         with:
-          key: ${{ matrix.os }}-${{ matrix.ghc-version }}-${{ github.sha }}
+          key: ${{ matrix.ghc-version }}-${{ github.sha }}
           path: ~/.cabal/store
+      - name: Upload coverage report
+        uses: actions/upload-artifact@v4
+        with:
+          name: constrained-${{matrix.ghc-version}}-coverage
+          path: coverage-report.md
+          if-no-files-found: error
+          compression-level: 0
+          retention-days: 1
+
+  report:
+    name: Generate coverage report
+
+    if: github.event.pull_request
+
+    needs: linux
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Download coverage report
+        uses: actions/download-artifact@v4
+        with:
+          pattern: 'constrained-latest-coverage'
+          merge-multiple: true
+
+      - run: cat coverage-report.md
+
+      - name: Find Comment
+        uses: peter-evans/find-comment@v3
+        id: fc
+        with:
+          issue-number: ${{ github.event.pull_request.number }}
+          comment-author: 'github-actions[bot]'
+          body-includes: "expressions used"
+
+      - name: Create or update comment
+        uses: peter-evans/create-or-update-comment@v4
+        with:
+          comment-id: ${{ steps.fc.outputs.comment-id }}
+          issue-number: ${{ github.event.pull_request.number }}
+          body-path: coverage-report.md
+          edit-mode: replace

.gitignore

@@ -22,3 +22,4 @@ cabal.project.local~
 .HTF/
 .ghc.environment.*
 *.*.sw*
+*.tix

scripts/generate-coverage-comment.sh

@@ -0,0 +1,4 @@
+#!/bin/sh
+
+echo "# Coverage report"
+hpc report $1 | awk '{sub(/^[ \t]*/, "& - ")1; sub(/^  /, "", $0); print}'