Use GH Action instead of on path filtering (conda#12180)

.github/workflows/tests.yml

@@ -10,24 +10,10 @@ on:
     branches:
       - main
       - feature/**
-    paths:  # run if src/tests/recipe are modified
-      - conda/**
-      - conda_env/**
-      - tests/**
-      - '*.py'
-      - recipe/**
-      - .github/workflows/tests.yml
 
   # NOTE: github.event context is pull_request payload:
   # https://docs.github.com/en/developers/webhooks-and-events/webhooks/webhook-events-and-payloads#pull_request
   pull_request:
-    paths:
-      - conda/**
-      - conda_env/**
-      - tests/**
-      - '*.py'
-      - recipe/**
-      - .github/workflows/tests.yml
 
 concurrency:
   # Concurrency group that uses the workflow name and PR number if available
@@ -39,7 +25,36 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
+  # detect whether any code changes are included in this PR
+  changes:
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: read
+    outputs:
+      code: ${{ steps.filter.outputs.code }}
+    steps:
+      - uses: actions/checkout@v3
+        # dorny/paths-filter needs git clone for push events
+        # https://github.com/marketplace/actions/paths-changes-filter#supported-workflows
+        if: github.event_name == 'push'
+      - uses: dorny/paths-filter@4512585405083f25c027a35db413c2b3b9006d50
+        id: filter
+        with:
+          filters: |
+            code:
+              - 'conda/**'
+              - 'conda_env/**'
+              - 'tests/**'
+              - '*.py'
+              - 'recipe/**'
+              - '.github/workflows/tests.yml'
+
+  # windows test suite
   windows:
+    # only run test suite if there are code changes
+    needs: changes
+    if: needs.changes.outputs.code == 'true'
+
     runs-on: windows-2019
     strategy:
       fail-fast: false
@@ -115,7 +130,12 @@ jobs:
             test-report.xml
           retention-days: 1
 
+  # linux test suite
   linux:
+    # only run test suite if there are code changes
+    needs: changes
+    if: needs.changes.outputs.code == 'true'
+
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
@@ -159,7 +179,12 @@ jobs:
             test-report.xml
           retention-days: 1
 
+  # linux-qemu test suite
   linux-qemu:
+    # only run test suite if there are code changes
+    needs: changes
+    if: needs.changes.outputs.code == 'true'
+
     # Run one single fast test per docker+qemu emulated linux platform to test that
     # test execution is possible there (container+tools+dependencies work). Can be
     # changed / extended to run specific tests in case there are platform related
@@ -207,7 +232,12 @@ jobs:
             test-report.xml
           retention-days: 1
 
+  # macos test suite
   macos:
+    # only run test suite if there are code changes
+    needs: changes
+    if: needs.changes.outputs.code == 'true'
+
     runs-on: macos-latest
     strategy:
       fail-fast: false
@@ -280,10 +310,12 @@ jobs:
             test-report.xml
           retention-days: 1
 
-  analyze:
-    name: Analyze results
-    needs: [windows, linux, linux-qemu, macos]
-    if: always()
+  # aggregate and upload
+  aggregate:
+    # only aggregate test suite if there are code changes
+    needs: [changes, windows, linux, linux-qemu, macos]
+    if: needs.changes.outputs.code == 'true' && always()
+
     runs-on: ubuntu-latest
     steps:
       - name: Download test results
@@ -303,12 +335,21 @@ jobs:
         with:
           paths: ./test-results-${{ github.sha }}-**/test-report*.xml
 
-      # required check
+  # required check
+  analyze:
+    name: Analyze results
+    needs: [windows, linux, linux-qemu, macos, aggregate]
+    if: always()
+
+    runs-on: ubuntu-latest
+    steps:
       - name: Decide whether the needed jobs succeeded or failed
-        uses: re-actors/alls-green@release/v1
+        uses: re-actors/alls-green@05ac9388f0aebcb5727afa17fcccfecd6f8ec5fe
         with:
+          allowed-skips: ${{ toJSON(needs) }}
           jobs: ${{ toJSON(needs) }}
 
+  # canary builds
   build:
     name: Canary Build
     needs: [analyze]