Enable codecov and generate metadata file as artifact

.buildkite/pipeline.yml

@@ -4,13 +4,18 @@ steps:
       queue: "init"
       docker: "*"
     command: ".buildkite/scripts/fossa.sh"
+
   - label: ":golang: unit-test"
     agents:
       queue: "workers"
       docker: "*"
-    command: "make unit_test"
+    commands:
+      - "make unit_test"
+      - ".buildkite/scripts/gen_coverage_metadata.sh .build/metadata.txt"
     artifact_paths:
       - ".build/*/coverage/*.out"
+      - ".build/cover.out"
+      - ".build/metadata.txt"
     plugins:
       - docker-compose#v3.0.0:
           run: unit-test

.buildkite/scripts/gen_coverage_metadata.sh

@@ -0,0 +1,17 @@
+#!/bin/sh
+
+set -ex
+
+# This script generates coverage metadata for the coverage report.
+# Output is used by SonarQube integration in Uber and not used by OS repo coverage tool itself.
+
+# Example output:
+#   commit-sha: 6953daa563e8e44512bc349c9608484cfd4ec4ff
+#   timestamp: 2024-03-04T19:29:16Z
+
+output_path="$1"
+
+echo "commit-sha: $(git rev-parse HEAD)" > "$output_path"
+echo "timestamp: $(date -u +%Y-%m-%dT%H:%M:%SZ)" >> "$output_path"
+
+echo "Coverage metadata written to $output_path"

.github/workflows/codecov.yml

@@ -0,0 +1,30 @@
+name: Workflow for Codecov integration
+on: [push, pull_request]
+jobs:
+  codecov:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Set up Go
+        uses: actions/setup-go@v4
+        with:
+          go-version: 1.22.x
+          cache: false
+
+      - name: Download dependencies
+        run: go mod download
+
+      - name: Test and generate coverage report
+        run: make unit_test
+
+      - name: Upload coverage reports to Codecov
+        uses: codecov/codecov-action@v4.0.1 # https://github.com/codecov/codecov-action
+        with:
+          file: .build/cover.out
+          exclude: ./
+          token: ${{ secrets.CODECOV_TOKEN }}
+          slug: uber-go/cadence-client

codecov.yml

@@ -0,0 +1,40 @@
+# Refs:
+# - https://docs.codecov.com/docs/common-recipe-list
+# - https://docs.codecov.com/docs/codecovyml-reference
+#
+# After making changes, run below command to validate
+# curl --data-binary @codecov.yml https://codecov.io/validate
+coverage:
+  range: 80...100
+  round: down
+  precision: 2
+  status:
+    project:                   # measuring the overall project coverage
+      default:                 # context, you can create multiple ones with custom titles
+        informational: true
+        target: 85%            # specify the target coverage for each commit status
+                               #   option: "auto" (compare against parent commit or pull request base)
+                               #   option: "X%" a static target percentage to hit
+        threshold: 0%          # allow the coverage drop by x% before marking as failure
+        if_ci_failed: ignore   # require the CI to pass before setting the status
+    patch:
+      default:
+        informational: true
+comment:
+  layout: "header, files, footer"
+  hide_project_coverage: false
+codecov:
+  require_ci_to_pass: false
+ignore:
+  - "**/*_generated.go"
+  - "**/*_mock.go"
+  - "**/testdata/**"
+  - "**/*_test.go"
+  - "**/*_testsuite.go"
+  - "compatibility/**"
+  - "idls/**"
+  - "internal/compatibility/**"
+  - "internal/tools/**"
+  - "mocks/**"
+  - "test/**"
+  - "testsuite/**"