ci: add Go-related workflows and steps

.github/workflows/build.yml

@@ -78,6 +78,15 @@ jobs:
           path: offchain/schema.graphql
           if-no-files-found: error
 
+      - name: Install Go
+        uses: actions/setup-go@v4
+        with:
+          go-version-file: 'go.mod'
+
+      - name: Run Go tests
+        working-directory: ${{ github.workspace }}
+        run: go test ./internal/pkg/services
+
   build_docker:
     runs-on: ubuntu-22.04
     needs:

.github/workflows/go-code-quality.yml

@@ -0,0 +1,34 @@
+name: Assess Go code quality
+
+on:
+  push:
+    paths:
+      - ".github/workflows/go-code-quality.yml"
+      - "cmd/**"
+      - "internal/**"
+
+jobs:
+  assess-go-code-quality:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          submodules: recursive
+
+      - uses: actions/setup-go@v4
+        with:
+          go-version-file: "go.mod"
+
+      - name: Check code format
+        run: |
+          output=$(gofmt -s -l .)
+          if [ -n "$output" ]; then 
+            echo "$output"
+            exit 1; 
+          fi
+
+      - name: Run linter
+        uses: golangci/golangci-lint-action@v3
+        with:
+          version: v1.54.2

.github/workflows/rust-code-quality.yml

@@ -4,7 +4,7 @@ name: Assess Rust code quality
 on:
   push:
     paths:
-      - '.github/workflows/code-quality.yml'
+      - '.github/workflows/rust-code-quality.yml'
       - 'offchain/**'
 
 jobs:

internal/pkg/services/graphql-service.go

@@ -30,7 +30,10 @@ func (g GraphQLService) Start(ctx context.Context) error {
 	go func() {
 		<-ctx.Done()
 		fmt.Printf("%v: %v\n", g.String(), ctx.Err())
-		cmd.Process.Signal(syscall.SIGTERM)
+		if err := cmd.Process.Signal(syscall.SIGTERM); err != nil {
+			msg := "%v: failed to send SIGTERM to %v\n"
+			fmt.Printf(msg, g.String(), binaryName)
+		}
 	}()
 
 	err := cmd.Wait()

internal/pkg/services/graphql-service_test.go

@@ -0,0 +1,49 @@
+package services
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"syscall"
+	"testing"
+	"time"
+)
+
+func TestGraphQLService(t *testing.T) {
+	t.Run("it stops when the context is cancelled", func(t *testing.T) {
+		service := GraphQLService{}
+		setupEnvVars()
+		ctx, cancel := context.WithCancel(context.Background())
+		exit := make(chan error)
+
+		go func() {
+			<-time.After(100 * time.Millisecond)
+			if err := service.Start(ctx); err != nil {
+				exit <- err
+			}
+		}()
+
+		<-time.After(200 * time.Millisecond)
+		cancel()
+
+		err := <-exit
+		exitError, ok := err.(*exec.ExitError)
+		if !ok || !assertExitErrorWasCausedBy(exitError, syscall.SIGTERM) {
+			fmt.Printf("service exited for the wrong reason: %v", err)
+			t.FailNow()
+		}
+	})
+}
+
+func setupEnvVars() {
+	abs, _ := filepath.Abs("../../../offchain/target/debug")
+	os.Setenv("PATH", abs)
+	os.Setenv("POSTGRES_PASSWORD", "pw")
+}
+
+func assertExitErrorWasCausedBy(err *exec.ExitError, signal syscall.Signal) bool {
+	status := err.Sys().(syscall.WaitStatus)
+	return status.Signal() == signal
+}