From 2c7b3778812b753bdbf59c16ff70941dc7180cd8 Mon Sep 17 00:00:00 2001
From: Paulo Janotti <pjanotti@splunk.com>
Date: Thu, 9 Jan 2025 10:15:14 -0800
Subject: [PATCH] [chore] Add scoped GH action to test affected components on
 Windows  (#37106)

#### Description
Many times changes that break Windows CI are merged since it is not
apparent that they will break on Windows. Given the cost of running
Windows CI for every PR the label `Run Windows` is only added in few
cases. This change adds make targets that allow to run make commands
only for tests and dependencies affected by files being changed.

It uses a simple detection of go files that were changed and look to the
import commands to find the components that depend directly on the
package being changed.

#### Link to tracking issue
Relates to #36788

#### Testing
Validated on my fork, e.g.:
https://github.com/pjanotti/opentelemetry-service-contrib/actions/runs/12659871185

#### Documentation
N/A
---
 .github/workflows/scoped-test.yaml | 74 ++++++++++++++++++++++++++++++
 Makefile.Common                    | 40 ++++++++++++++++
 2 files changed, 114 insertions(+)
 create mode 100644 .github/workflows/scoped-test.yaml

diff --git a/.github/workflows/scoped-test.yaml b/.github/workflows/scoped-test.yaml
new file mode 100644
index 000000000000..0a525de6d64d
--- /dev/null
+++ b/.github/workflows/scoped-test.yaml
@@ -0,0 +1,74 @@
+name: scoped-test
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    types: [opened, synchronize, reopened]
+
+jobs:
+  changedfiles:
+    runs-on: ubuntu-latest
+    if: ${{ github.actor != 'dependabot[bot]' }}
+    outputs:
+      go_sources: ${{ steps.changed-files.outputs.sources_all_changed_files }}
+      go_tests: ${{ steps.changed-files.outputs.tests_all_changed_files }}
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Get changed go files
+        id: changed-files
+        uses: tj-actions/changed-files@v45
+        with:
+          files_yaml: |
+            sources:
+              - '**/*.go'
+              - '!**/*_test.go'
+            tests:
+              - '**/*_test.go'
+
+  scoped-tests:
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ windows-latest ]
+    runs-on: ${{ matrix.os }}
+    needs: changedfiles
+    steps:
+      - name: Echo changed files
+        shell: bash
+        run: |
+          echo "go_sources: ${{ needs.changedfiles.outputs.go_sources }}"
+          echo "go_tests: ${{ needs.changedfiles.outputs.go_tests }}"
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: "1.22.8"
+          cache: false
+
+      - name: Try to restore go-cache
+        id: go-cache
+        timeout-minutes: 25
+        uses: actions/cache/restore@v4
+        with:
+          path: |
+            ~/go/bin
+            ~/go/pkg/mod
+            ./.tools
+          key: go-cache-${{ runner.os }}-${{ hashFiles('**/go.sum') }}
+
+      - name: Run changed tests
+        if: needs.changedfiles.outputs.go_tests
+        env:
+          CHANGED_GOLANG_TESTS: ${{ needs.changedfiles.outputs.go_tests }}
+        run: |
+          make run-changed-tests
+
+      - name: Run tests on dependent components
+        if: needs.changedfiles.outputs.go_sources
+        env:
+          CHANGED_GOLANG_SOURCES: ${{ needs.changedfiles.outputs.go_sources }}
+        run: |
+          make for-affected-components CMD="make test"
diff --git a/Makefile.Common b/Makefile.Common
index 81b7a0a3ed5a..021a39c847b7 100644
--- a/Makefile.Common
+++ b/Makefile.Common
@@ -266,3 +266,43 @@ testifylint-fix:
 gci: $(TOOLS_BIN_DIR)/gci
 	@echo "running $(GCI)"
 	@$(GCI) write -s standard -s default -s "prefix(github.com/open-telemetry/opentelemetry-collector-contrib)" $(ALL_SRC_AND_DOC)
+
+CHANGED_GOLANG_SOURCES?=$(shell git diff main --name-only | grep -E '.*\.go$$' | grep -v -E '.*_test\.go$$')
+.PHONY: for-affected-components
+for-affected-components:
+	@echo "Checking for affected components..."
+	@if [ -z '$(CHANGED_GOLANG_SOURCES)' ]; then \
+		echo "No go source changes detected in shippable code."; \
+	else \
+		cd $(SRC_ROOT); \
+		DEPENDENT_PKGS=$$(echo $(CHANGED_GOLANG_SOURCES) | xargs sed -n 's|^package .* // import "\(.*\)"$$|\1|p' | uniq); \
+		if [ -z '$${DEPENDENT_PKGS}' ]; then \
+			echo "No other package depends on the one being changed."; \
+		else \
+			DEPENDENT_PKG_DIRS=$$(echo $${DEPENDENT_PKGS} | tr ' ' '\n' | xargs -I {} grep --include=go.mod -rl {} | xargs dirname | uniq); \
+			set -e; for dir in $$(echo $${DEPENDENT_PKG_DIRS}); do \
+			(cd "$${dir}" && \
+				echo "running $${CMD} in $${dir}" && \
+				$${CMD} ); \
+			done \
+		fi \
+	fi
+
+CHANGED_GOLANG_TESTS?=$(shell git diff main --name-only | grep -E '.*_test\.go$$')
+.PHONY: run-changed-tests
+run-changed-tests:
+	@echo "Checking for affected tests..."
+	@if [ -z '$(CHANGED_GOLANG_TESTS)' ]; then \
+		echo "No go test changes detected."; \
+	else \
+		cd $(SRC_ROOT); \
+		AFFECTED_TEST_DIRS=$$(echo $(CHANGED_GOLANG_TESTS) | tr ' ' '\n' | xargs dirname | uniq); \
+		if [ -z '$${AFFECTED_TEST_DIRS}' ]; then \
+			echo "Failed to find the affected test directories."; \
+		else \
+			set -e; for dir in $$(echo $${AFFECTED_TEST_DIRS}); do \
+			(cd "$${dir}" && \
+				$(GOTESTSUM) $(GOTESTSUM_OPT) --packages="./..." -- $(GOTEST_OPT) ); \
+			done \
+		fi \
+	fi