Generate code on Mac

Problem
-------
Currently code is generated only for Linux.
Also the parser check prevents us from omitting codegen in PR.

Solution
--------
1. Generate parser for Mac as well. For some reason Windows fails
   to generate the parser.
2. Run the parser check only if the PR contains C code changes

Author: eed3si9n

.github/workflows/ci.yml

@@ -10,13 +10,17 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        os: [macos-latest, ubuntu-20.04, windows-2019]
+        # Use windows-2019 for Windows.
+        # Currently it fails to generate parser.
+        os: [macos-latest, ubuntu-20.04]
     env:
       SCALA_SCALA_DIR: /home/runner/work/tree-sitter-scala/tree-sitter-scala/scala_scala
       DOTTY_DIR: /home/runner/work/tree-sitter-scala/tree-sitter-scala/dotty
     steps:
       - name: checkout tree-sitter-scala
         uses: actions/checkout@v3
+        with:
+          fetch-depth: 10
 
       - name: checkout scala/scala
         uses: actions/checkout@v3
@@ -32,22 +36,38 @@ jobs:
           ref: 3.2.1
           path: dotty
 
+      - name: Get changed files
+        if: ${{ runner.os == 'Linux' }}
+        id: changes
+        run: |
+          echo "all=$(git diff --name-only --diff-filter=ACMRT ${{ github.event.pull_request.base.sha }} ${{ github.sha }} | xargs)" >> $GITHUB_OUTPUT
+          echo "c=$(git diff --name-only --diff-filter=ACMRT ${{ github.event.pull_request.base.sha }} ${{ github.sha }} | grep '.\(c\|h\)$' | xargs)" >> $GITHUB_OUTPUT
+
       - uses: actions/setup-node@v3
         with:
           node-version: 18
 
       - name: Test C stack code
         run: gcc test/test-stack.c -o a.out && ./a.out
 
-      - name: Generate and check parser
-        if: ${{ runner.os == 'Linux' }}
+      - name: Generate parser
+        shell: bash
+        run: npm install && npm run build
+
+      - name: Check parser (Linux)
+        if: ${{ runner.os == 'Linux' && steps.changes.outputs.c }}
+        shell: bash
         run: |
-          npm install && npm run build
-          git diff --quiet || (echo "::error file=grammar.js::Generated parser differs from the checked in version" && exit 1)
+          # `git diff --quiet` doesn't seem to work on Github Actions
+          changes=$(git diff --name-only --diff-filter=ACMRT | xargs)
+          if [ ! "$changes" ]; then
+            echo "::error file=grammar.js::Generated parser differs from the checked in version"
+            exit 1
+          fi
 
       - name: Parser tests
         shell: bash
-        run: npm install && npm run test
+        run: npm run test
 
       - name: Smoke test
         if: ${{ runner.os == 'Linux' }}