Migrate to GitHub Actions for unit tests and set up code coverage (#396)

* Set up GitHub Actions unit tests and code coverage
* fetch-depth: 2
* Specify JaCoCo version

.github/workflows/unit-tests.yaml

@@ -0,0 +1,43 @@
+name: Unit Tests
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  unit-tests:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        java: [8, 11]
+    env:
+      CLOUDSDK_CORE_DISABLE_USAGE_REPORTING: true
+      CLOUDSDK_CORE_DISABLE_PROMPTS: true
+      # for Gradle
+      TERM: dumb
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          fetch-depth: 2
+      - uses: actions/setup-java@v1
+        with:
+          java-version: ${{ matrix.java }}
+      - uses: actions/cache@v2
+        with:
+          path: |
+            ~/.m2/repository
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}
+          restore-keys: |
+            ${{ runner.os }}-gradle-
+      - name: Run tests
+        run: |
+          ./gradlew clean build jacocoTestReport --stacktrace
+      - name: Test Coverage
+        uses: codecov/codecov-action@v1
+        with:
+          name: actions ${{matrix.java}}

build.gradle

@@ -22,6 +22,7 @@ plugins {
   id 'net.researchgate.release' version '2.6.0'
   id 'com.github.sherter.google-java-format' version '0.8'
   id 'checkstyle'
+  id 'jacoco'
 }
 
 repositories {
@@ -164,11 +165,24 @@ check.dependsOn verifyGoogleJavaFormat
 // to auto-format run ./gradlew googleJavaFormat
 
 checkstyle {
-  toolVersion = "8.18"
+  toolVersion = '8.18'
   // get the google_checks.xml file from the actual tool we're invoking
   config = resources.text.fromArchiveEntry(configurations.checkstyle[0], 'google_checks.xml')
   maxErrors = 0
   maxWarnings = 0
   checkstyleTest.enabled = false
 }
 /* FORMATTING */
+
+/* TEST COVERAGE */
+jacoco {
+  toolVersion = '0.8.6'
+}
+
+jacocoTestReport {
+  reports {
+    xml.enabled true
+    html.enabled false
+  }
+}
+/* TEST COVERAGE */