From 3b888662886a52f36c68906074538c476e1d2249 Mon Sep 17 00:00:00 2001
From: Alex Boten <aboten@lightstep.com>
Date: Fri, 2 Jun 2023 07:34:09 -0700
Subject: [PATCH] [chore] enable coverage for unit tests (#22966)

This re-enables unit test coverage for the repository. Coverage will not immediately include integration tests.

Fixes #8394
---------

Signed-off-by: Alex Boten <aboten@lightstep.com>
---
 .github/workflows/build-and-test.yml | 22 ++++++++++++++++++++++
 .gitignore                           |  5 ++---
 Makefile                             | 12 ++++++------
 Makefile.Common                      |  7 ++++++-
 4 files changed, 36 insertions(+), 10 deletions(-)

diff --git a/.github/workflows/build-and-test.yml b/.github/workflows/build-and-test.yml
index 016ab329c521..cb88004bf00a 100644
--- a/.github/workflows/build-and-test.yml
+++ b/.github/workflows/build-and-test.yml
@@ -254,7 +254,16 @@ jobs:
           path: ~/.cache/go-build
           key: go-test-build-${{ runner.os }}-${{ matrix.go-version }}-${{ hashFiles('**/go.sum') }}
       - name: Run Unit Tests
+        if: ${{ matrix.go-version == '1.19' }}
         run: make gotest GROUP=${{ matrix.group }}
+      - name: Run Unit Tests With Coverage
+        if: ${{ matrix.go-version == '1.20' }} # only run coverage on one version
+        run: make gotest-with-cover GROUP=${{ matrix.group }}
+      - uses: actions/upload-artifact@v3
+        if: ${{ matrix.go-version == '1.20' }} # only run coverage on one version
+        with:
+          name: coverage-artifacts
+          path: ${{ matrix.group }}-coverage.txt
   unittest:
     if: ${{ github.actor != 'dependabot[bot]' && always() }}
     strategy:
@@ -274,6 +283,19 @@ jobs:
             echo "One or more matrix jobs failed."
             false
           fi
+  coverage:
+    runs-on: ubuntu-latest
+    needs: [unittest]
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/download-artifact@v3
+        with:
+          name: coverage-artifacts
+      - name: Upload coverage report
+        uses: codecov/codecov-action@v3
+        with:
+          fail_ci_if_error: true
+          verbose: true
 
   integration-tests:
     runs-on: ubuntu-latest
diff --git a/.gitignore b/.gitignore
index da76a7fd2fde..7518e3156227 100644
--- a/.gitignore
+++ b/.gitignore
@@ -27,9 +27,8 @@ dist/
 *.DS_Store
 
 # Coverage
-coverage.txt
-integration-coverage.txt
-coverage.html
+coverage/*
+*-coverage.txt
 integration-coverage.html
 
 # Wix
diff --git a/Makefile b/Makefile
index bb7cb1a7260f..5485ae6cd25d 100644
--- a/Makefile
+++ b/Makefile
@@ -73,12 +73,6 @@ all-common:
 e2e-test: otelcontribcol oteltestbedcol
 	$(MAKE) -C testbed run-tests
 
-.PHONY: unit-tests-with-cover
-unit-tests-with-cover:
-	@echo Verifying that all packages have test files to count in coverage
-	@internal/buildscripts/check-test-files.sh $(subst github.com/open-telemetry/opentelemetry-collector-contrib/,./,$(ALL_PKGS))
-	@$(MAKE) $(FOR_GROUP_TARGET) TARGET="do-unit-tests-with-cover"
-
 TARGET="do-integration-tests-with-cover"
 .PHONY: integration-tests-with-cover
 integration-tests-with-cover: $(INTEGRATION_MODS)
@@ -101,6 +95,11 @@ gomoddownload:
 gotest:
 	$(MAKE) $(FOR_GROUP_TARGET) TARGET="test"
 
+.PHONY: gotest-with-cover
+gotest-with-cover:
+	@$(MAKE) $(FOR_GROUP_TARGET) TARGET="test-with-cover"
+	$(GOCMD) tool covdata textfmt -i=./coverage/unit -o ./$(GROUP)-coverage.txt
+
 .PHONY: gofmt
 gofmt:
 	$(MAKE) $(FOR_GROUP_TARGET) TARGET="fmt"
@@ -385,6 +384,7 @@ clean:
 	@echo "Removing coverage files"
 	find . -type f -name 'coverage.txt' -delete
 	find . -type f -name 'coverage.html' -delete
+	find . -type f -name 'coverage.out' -delete
 	find . -type f -name 'integration-coverage.txt' -delete
 	find . -type f -name 'integration-coverage.html' -delete
 
diff --git a/Makefile.Common b/Makefile.Common
index dcb9b294c619..7144da77ce49 100644
--- a/Makefile.Common
+++ b/Makefile.Common
@@ -96,7 +96,12 @@ common: lint
 .PHONY: test
 test:
 	$(GOTEST) $(GOTEST_OPT) ./...
-	
+
+.PHONY: test-with-cover
+test-with-cover:
+	mkdir -p $(PWD)/coverage/unit
+	$(GOTEST) -cover ./... -covermode=atomic -args -test.gocoverdir="$(PWD)/coverage/unit"
+
 .PHONY: do-unit-tests-with-cover
 do-unit-tests-with-cover:
 	@echo "running $(GOCMD) unit test ./... + coverage in `pwd`"