Create Invalidations.yml (#75)

This is based on https://github.com/julia-actions/julia-invalidations. Adding such checks came up in https://discourse.julialang.org/t/potential-performance-regressions-in-julia-1-8-for-special-un-precompiled-type-dispatches-and-how-to-fix-them/86359. I suggest to add this check here since this package is widely used as a dependency.

See also SciML/MuladdMacro.jl#26 and SciML/MuladdMacro.jl#29

Co-authored-by: Hendrik Ranocha <ranocha@users.noreply.github.com>

Author: ScottPJones

.github/workflows/Invalidations.yml

@@ -0,0 +1,40 @@
+name: Invalidations
+
+on:
+  pull_request:
+
+concurrency:
+  # Skip intermediate builds: always.
+  # Cancel intermediate builds: always.
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  evaluate:
+    # Only run on PRs to the default branch.
+    # In the PR trigger above branches can be specified only explicitly whereas this check should work for master, main, or any other default branch
+    if: github.base_ref == github.event.repository.default_branch
+    runs-on: ubuntu-latest
+    steps:
+    - uses: julia-actions/setup-julia@v1
+      with:
+        version: '1'
+    - uses: actions/checkout@v3
+    - uses: julia-actions/julia-buildpkg@v1
+    - uses: julia-actions/julia-invalidations@v1
+      id: invs_pr
+
+    - uses: actions/checkout@v3
+      with:
+        ref: ${{ github.event.repository.default_branch }}
+    - uses: julia-actions/julia-buildpkg@v1
+    - uses: julia-actions/julia-invalidations@v1
+      id: invs_default
+    
+    - name: Report invalidation counts
+      run: |
+        echo "Invalidations on default branch: ${{ steps.invs_default.outputs.total }} (${{ steps.invs_default.outputs.deps }} via deps)" >> $GITHUB_STEP_SUMMARY
+        echo "This branch: ${{ steps.invs_pr.outputs.total }} (${{ steps.invs_pr.outputs.deps }} via deps)" >> $GITHUB_STEP_SUMMARY
+    - name: Check if the PR does increase number of invalidations
+      if: steps.invs_pr.outputs.total > steps.invs_default.outputs.total
+      run: exit 1