[ ci ] controlling builds via commit messages (#1766)

Author: gallais

.github/workflows/ci-idris2.yml

@@ -6,16 +6,56 @@ on:
       - '*'
     tags:
       - '*'
+    paths-ignore:
+      - 'docs/**'
+      - 'icons/**'
+      - '*.md'
+      - 'CONTRIBUTORS'
+      - 'LICENSE'
+      - '.github/workflows/ci-lint.yml'
+      - '.github/workflows/ci-sphinx.yml'
+      - '.github/workflows/ci-super-linter.yml'
   pull_request:
     branches:
       - master
       - main
+    paths-ignore:
+      - 'docs/**'
+      - 'icons/**'
+      - '*.md'
+      - 'CONTRIBUTORS'
+      - 'LICENSE'
+      - '.github/workflows/ci-lint.yml'
+      - '.github/workflows/ci-sphinx.yml'
+      - '.github/workflows/ci-super-linter.yml'
 
 env:
   IDRIS2_VERSION: 0.4.0 # For previous-version build
 
 jobs:
 
+  initialise:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout Project
+        uses: actions/checkout@v2
+        with:
+          # for pull_request so we can do HEAD^2
+          fetch-depth: 2
+
+      - name: Get commit message
+        id: get_commit_message
+        run: |
+          if   [[ '${{ github.event_name }}' == 'push' ]]; then
+            echo ::set-output name=commit_message::$(git log --format=%B -n 1 HEAD)
+          elif [[ '${{ github.event_name }}' == 'pull_request' ]]; then
+            echo ::set-output name=commit_message::$(git log --format=%B -n 1 HEAD^2)
+          fi
+
+    outputs:
+      commit_message:
+        echo "${{ steps.get_commit_message.outputs.commit_message }}"
+
   ######################################################################
   # Build from the previous version
   # We perform this check before all the other ones because:
@@ -24,7 +64,10 @@ jobs:
   ######################################################################
 
   quick-check:
+    needs: initialise
     runs-on: ubuntu-latest
+    if: |
+      !contains(needs.initialise.outputs.commit_message, '[ci: skip]')
     env:
       IDRIS2_CG: chez
       SCHEME: scheme
@@ -79,6 +122,10 @@ jobs:
   ubuntu-bootstrap-chez:
     needs: quick-check
     runs-on: ubuntu-latest
+    if: |
+      !contains(needs.initialise.outputs.commit_message, '[ci:')
+      || contains(needs.initialise.outputs.commit_message, '[ci: ubuntu]')
+      || contains(needs.initialise.outputs.commit_message, '[ci: chez]')
     env:
       IDRIS2_CG: chez
       SCHEME: scheme
@@ -104,6 +151,10 @@ jobs:
   macos-bootstrap-chez:
     needs: quick-check
     runs-on: macos-latest
+    if: |
+      !contains(needs.initialise.outputs.commit_message, '[ci:')
+      || contains(needs.initialise.outputs.commit_message, '[ci: macos]')
+      || contains(needs.initialise.outputs.commit_message, '[ci: chez]')
     env:
       SCHEME: chez
     steps:
@@ -128,6 +179,10 @@ jobs:
   windows-bootstrap-chez:
     needs: quick-check
     runs-on: windows-latest
+    if: |
+      !contains(needs.initialise.outputs.commit_message, '[ci:')
+      || contains(needs.initialise.outputs.commit_message, '[ci: windows]')
+      || contains(needs.initialise.outputs.commit_message, '[ci: chez]')
     env:
       MSYSTEM: MINGW64
       MSYS2_PATH_TYPE: inherit
@@ -173,6 +228,10 @@ jobs:
   nix-bootstrap-chez:
     needs: quick-check
     runs-on: ubuntu-latest
+    if: |
+      !contains(needs.initialise.outputs.commit_message, '[ci:')
+      || contains(needs.initialise.outputs.commit_message, '[ci: nix]')
+      || contains(needs.initialise.outputs.commit_message, '[ci: chez]')
     steps:
     - uses: actions/checkout@v2
       with:
@@ -187,6 +246,10 @@ jobs:
   ubuntu-bootstrap-racket:
     needs: quick-check
     runs-on: ubuntu-latest
+    if: |
+      !contains(needs.initialise.outputs.commit_message, '[ci:')
+      || contains(needs.initialise.outputs.commit_message, '[ci: ubuntu]')
+      || contains(needs.initialise.outputs.commit_message, '[ci: racket]')
     env:
       IDRIS2_CG: racket
     steps:
@@ -292,6 +355,9 @@ jobs:
   ubuntu-self-host-previous-version:
     needs: quick-check
     runs-on: ubuntu-latest
+    if: |
+      !contains(needs.initialise.outputs.commit_message, '[ci:')
+      || contains(needs.initialise.outputs.commit_message, '[ci: ubuntu]')
     env:
       IDRIS2_CG: chez
     steps: