jobs: enable quickstart test (GoogleCloudPlatform#611)

jobs/v3/quickstart/main_test.go

@@ -5,14 +5,38 @@
 package main
 
 import (
+	"context"
 	"io/ioutil"
 	"os"
 	"strings"
 	"testing"
+
+	"github.com/GoogleCloudPlatform/golang-samples/internal/testutil"
+	"golang.org/x/oauth2/google"
+	talent "google.golang.org/api/jobs/v3"
 )
 
+func checkServiceAvailable(t *testing.T, projectID string) {
+	client, err := google.DefaultClient(context.Background(), talent.CloudPlatformScope)
+	if err != nil {
+		t.Skipf("DefaultClient: %v", err)
+	}
+
+	service, err := talent.New(client)
+	if err != nil {
+		t.Skipf("createCTSService: service account likely in different project: %v", err)
+	}
+	if _, err := service.Projects.Companies.List("projects/" + projectID).Do(); err != nil {
+		t.Skip("List: service account likely in different project")
+	}
+}
+
 func TestMain(t *testing.T) {
-	t.Skip("Need to set GOOGLE_CLOUD_PROJECT")
+	tc := testutil.SystemTest(t)
+	checkServiceAvailable(t, tc.ProjectID)
+
+	os.Setenv("GOOGLE_CLOUD_PROJECT", tc.ProjectID)
+
 	oldStdout := os.Stdout
 	r, w, _ := os.Pipe()
 	os.Stdout = w