[ggj] Add overall test coverage

.github/workflows/ci.yaml

@@ -18,6 +18,8 @@ jobs:
         java: [8, 11]
     steps:
       - uses: actions/checkout@v2
+        with:
+          fetch-depth: 1
       - uses: actions/setup-java@v1
         with:
           java-version: ${{ matrix.java }}
@@ -60,6 +62,15 @@ jobs:
           name: artifacts
           path: ~/artifacts
 
+      - name: Generate Code Coverage Report
+        run: bazel coverage //src/test/... --combined_report=lcov
+
+      - name: Upload Code Coverage Report
+        uses: codecov/codecov-action@v1
+        with:
+          name: actions ${{ matrix.java }}
+          files: ./bazel-out/_coverage/_coverage_report.dat
+
   license-header:
     runs-on: ubuntu-latest
     steps:

README.md

@@ -1,3 +1,4 @@
+[![codecov](https://codecov.io/gh/googleapis/gapic-generator-java/branch/master/graph/badge.svg?token=3RUU37GX9U)](https://codecov.io/gh/googleapis/gapic-generator-java)
 # API Client Generator for Java
 
 A generator for protocol buffer described APIs for and in Java.

codecov.yml

@@ -0,0 +1,21 @@
+codecov:
+  notify:
+    require_ci_to_pass: yes
+
+  coverage:
+    precision: 2
+    round: down
+    range: 70...100
+
+    status:
+      project: true
+        default:
+          informational: true
+      patch: true
+        default:
+          informatioanl: true
+      changes: false
+
+  comment:
+    layout: "header, diff, uncovered"
+    behavior: default  # update if exists else create new