CI: Add GH actions to test and build Go packages

Author: kkohtaka

.github/workflows/build.yaml

@@ -0,0 +1,52 @@
+name: Test and build Go packages
+on:
+  - push
+  - pull_request
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-go@v3
+        with:
+          go-version-file: go.mod
+      - uses: actions/cache@v3
+        with:
+          path: |
+            ~/.cache/go-build
+            ~/go/pkg/mod
+          key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
+          restore-keys: |
+            ${{ runner.os }}-go-
+      - run: go test ./...
+
+  build:
+    runs-on: ubuntu-latest
+    needs:
+      - test
+    permissions:
+      contents: read
+      packages: write
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-go@v3
+        with:
+          go-version-file: go.mod
+      - uses: actions/cache@v3
+        with:
+          path: |
+            ~/.cache/go-build
+            ~/go/pkg/mod
+          key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
+          restore-keys: |
+            ${{ runner.os }}-go-
+      - run: go build -a -o bin/pr-size ./cmd/gh-actions-pr-size
+      - uses: elgohr/Publish-Docker-Github-Action@v4
+        with:
+          name: ${{ github.repository }}/gh-actions-pr-size
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+          registry: docker.pkg.github.com
+          no_push: true

.gitignore

@@ -0,0 +1 @@
+bin/