Cloud Storage (2nd Gen) Unit Test

Example unit test for a Cloud Storage-triggered function running on Cloud Functions (2nd Gen).

Code sample

C#

To authenticate to Cloud Functions, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

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using CloudNative.CloudEvents;
using Google.Cloud.Functions.Testing;
using Google.Events;
using Google.Events.Protobuf.Cloud.Storage.V1;
using Microsoft.Extensions.Logging;
using System;
using System.Threading;
using System.Threading.Tasks;
using Xunit;

namespace HelloWorld.Tests;

public class HelloGcsUnitTest
{
    [Fact]
    public async Task FileNameIsLogged()
    {
        // Prepare the inputs
        var data = new StorageObjectData { Name = "new-file.txt" };
        var cloudEvent = new CloudEvent
        {
            Type = StorageObjectData.FinalizedCloudEventType,
            Source = new Uri("//storage.googleapis.com", UriKind.RelativeOrAbsolute),
            Id = "1234",
            Data = data
        };
        var logger = new MemoryLogger<HelloGcs.Function>();

        // Execute the function
        var function = new HelloGcs.Function(logger);
        await function.HandleAsync(cloudEvent, data, CancellationToken.None);

        // Check the log results - just the entry starting with "File:".
        var logEntry = Assert.Single(logger.ListLogEntries(), entry => entry.Message.StartsWith("File:"));
        Assert.Equal("File: new-file.txt", logEntry.Message);
        Assert.Equal(LogLevel.Information, logEntry.Level);
    }
}

Go

To authenticate to Cloud Functions, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

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package helloworld

import (
	"context"
	"io/ioutil"
	"log"
	"os"
	"strings"
	"testing"
	"time"

	"github.com/cloudevents/sdk-go/v2/event"
	"github.com/googleapis/google-cloudevents-go/cloud/storagedata"
	"google.golang.org/protobuf/encoding/protojson"
	"google.golang.org/protobuf/types/known/timestamppb"
)

func TestHelloStorage(t *testing.T) {
	r, w, _ := os.Pipe()
	log.SetOutput(w)
	originalFlags := log.Flags()
	log.SetFlags(log.Flags() &^ (log.Ldate | log.Ltime))

	d := &storagedata.StorageObjectData{
		Name:        "hello_gcs.txt",
		TimeCreated: timestamppb.New(time.Now()),
	}

	jsonData, err := protojson.Marshal(d)
	if err != nil {
		t.Fatalf("protojson.Marshal: %v", err)
	}

	e := event.New()
	e.SetDataContentType("application/json")
	e.SetData(e.DataContentType(), jsonData)

	helloStorage(context.Background(), e)

	w.Close()
	log.SetOutput(os.Stderr)
	log.SetFlags(originalFlags)

	out, err := ioutil.ReadAll(r)
	if err != nil {
		t.Fatalf("ReadAll: %v", err)
	}
	got := string(out)
	if want := d.Name; strings.Contains(want, got) {
		t.Errorf("HelloStorage = %q, want to contain %q", got, want)
	}
	if want := d.TimeCreated.String(); strings.Contains(want, got) {
		t.Errorf("HelloStorage = %q, want to contain %q", got, want)
	}
}

Java

To authenticate to Cloud Functions, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

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import static com.google.common.truth.Truth.assertThat;

import com.google.common.testing.TestLogHandler;
import com.google.events.cloud.storage.v1.StorageObjectData;
import com.google.protobuf.InvalidProtocolBufferException;
import com.google.protobuf.Timestamp;
import com.google.protobuf.util.JsonFormat;
import io.cloudevents.CloudEvent;
import io.cloudevents.core.builder.CloudEventBuilder;
import java.net.URI;
import java.util.logging.Logger;
import org.junit.After;
import org.junit.BeforeClass;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/** Unit tests for main.java.com.example.functions.helloworld.HelloGcs. */
@RunWith(JUnit4.class)
public class HelloGcsTest {
  private static final TestLogHandler LOG_HANDLER = new TestLogHandler();
  private static final Logger logger = Logger.getLogger(HelloGcs.class.getName());

  @BeforeClass
  public static void beforeClass() throws Exception {
    logger.addHandler(LOG_HANDLER);
  }

  @After
  public void afterTest() {
    LOG_HANDLER.clear();
  }

  @Test
  public void helloGcs_shouldPrintFileName() throws InvalidProtocolBufferException {
    // Create event data
    String file = "foo.txt";
    String bucket = "gs://test-bucket";

    // Get the current time in milliseconds
    long millis = System.currentTimeMillis();

    // Create a Timestamp object
    Timestamp timestamp = Timestamp.newBuilder()
        .setSeconds(millis / 1000)
        .setNanos((int) ((millis % 1000) * 1000000))
        .build();

    StorageObjectData.Builder dataBuilder = StorageObjectData.newBuilder()
        .setName(file)
        .setBucket(bucket)
        .setMetageneration(10)
        .setTimeCreated(timestamp)
        .setUpdated(timestamp);

    String jsonData = JsonFormat.printer().print(dataBuilder);

    // Construct a CloudEvent
    CloudEvent event = CloudEventBuilder.v1()
        .withId("0")
        .withType("google.storage.object.finalize")
        .withSource(URI.create("https://example.com"))
        .withData("application/json", jsonData.getBytes())
        .build();

    new HelloGcs().accept(event);

    String actualBucket = LOG_HANDLER.getStoredLogRecords().get(2).getMessage();
    String actualFile = LOG_HANDLER.getStoredLogRecords().get(3).getMessage();
    assertThat(actualFile).contains("File: " + file);
    assertThat(actualBucket).contains("Bucket: " + bucket);
  }

  @Test
  public void helloGcs_shouldPrintNotifyIfDataIsNull() throws InvalidProtocolBufferException {
    // Construct a CloudEvent
    CloudEvent event = CloudEventBuilder.v1()
        .withId("0")
        .withType("google.storage.object.finalize")
        .withSource(URI.create("https://example.com"))
        .build();

    new HelloGcs().accept(event);

    String logMessage = LOG_HANDLER.getStoredLogRecords().get(2).getMessage();
    assertThat(logMessage).isEqualTo("No data found in cloud event payload!");
  }
}

Node.js

To authenticate to Cloud Functions, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

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const {getFunction} = require('@google-cloud/functions-framework/testing');

describe('functions_cloudevent_storage', () => {
  const assert = require('assert');
  const sinon = require('sinon');
  require('..');

  const stubConsole = function () {
    sinon.stub(console, 'error');
    sinon.stub(console, 'log');
  };

  const restoreConsole = function () {
    console.log.restore();
    console.error.restore();
  };

  beforeEach(stubConsole);
  afterEach(restoreConsole);

  it('helloGCS: should print out event', () => {
    const event = {
      id: '1234',
      type: 'mock-gcs-event',
      data: {
        bucket: 'my-bucket',
        name: 'my-file.txt',
      },
    };

    // Call tested function and verify its behavior
    const helloGCS = getFunction('helloGCS');
    helloGCS(event);

    assert(console.log.calledWith('Event ID: 1234'));
    assert(console.log.calledWith('Event Type: mock-gcs-event'));
    assert(console.log.calledWith('Bucket: my-bucket'));
    assert(console.log.calledWith('File: my-file.txt'));
  });
});

PHP

To authenticate to Cloud Functions, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

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namespace Google\Cloud\Samples\Functions\HelloworldStorage\Test;

use CloudEvents\V1\CloudEventImmutable;
use CloudEvents\V1\CloudEventInterface;

use PHPUnit\Framework\TestCase;

/**
 * Class SampleUnitTest.
 *
 * Unit test for 'Helloworld Storage' Cloud Function.
 */
class SampleUnitTest extends TestCase
{
    /**
     * Include the Cloud Function code before running any tests.
     *
     * @see https://phpunit.readthedocs.io/en/latest/fixtures.html
     */
    public static function setUpBeforeClass(): void
    {
        require_once __DIR__ . '/index.php';
    }

    public function dataProvider()
    {
        return [
            [
                'cloudevent' => new CloudEventImmutable(
                    uniqId(), // id
                    'storage.googleapis.com', // source
                    'google.cloud.storage.object.v1.finalized', // type
                    [
                        'bucket' => 'some-bucket',
                        'metageneration' => '1',
                        'name' => 'folder/friendly.txt',
                        'timeCreated' => '2020-04-23T07:38:57.230Z',
                        'updated' => '2020-04-23T07:38:57.230Z',
                    ] // data
                ),
                'statusCode' => '200',
            ],
        ];
    }

    /**
     * @dataProvider dataProvider
     */
    public function testFunction(CloudEventInterface $cloudevent): void
    {
        // Capture function output by overriding the function's logging behavior.
        // The 'LOGGER_OUTPUT' environment variable must be used in your function:
        //
        // $log = fopen(getenv('LOGGER_OUTPUT') ?: 'php://stderr', 'wb');
        // fwrite($log, 'Log Entry');
        putenv('LOGGER_OUTPUT=php://output');
        helloGCS($cloudevent);
        // Provided by PHPUnit\Framework\TestCase.
        $actual = $this->getActualOutput();

        // Test output includes the properties provided in the CloudEvent.
        foreach ($cloudevent->getData() as $property => $value) {
            $this->assertStringContainsString($value, $actual);
        }
        $this->assertStringContainsString($cloudevent->getId(), $actual);
        $this->assertStringContainsString($cloudevent->getType(), $actual);
    }
}

Python

To authenticate to Cloud Functions, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

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from cloudevents.http import CloudEvent
import pytest

import main


def test_functions_eventsource_storage(capsys: pytest.LogCaptureFixture) -> None:
    attributes = {
        "id": "5e9f24a",
        "type": "google.cloud.storage.object.v1.finalized",
        "source": "sourceUrlHere",
    }

    data = {
        "bucket": "test_bucket_for_storage",
        "name": "new_blob_uploaded",
        "generation": 1,
        "metageneration": 1,
        "timeCreated": "2021-10-10 00:00:00.000000Z",
        "updated": "2021-11-11 00:00:00.000000Z",
    }

    event = CloudEvent(attributes, data)

    (
        event_id,
        event_type,
        bucket,
        name,
        metageneration,
        timeCreated,
        updated,
    ) = main.hello_gcs(event)

    out, _ = capsys.readouterr()
    assert "5e9f24a" in event_id
    assert "google.cloud.storage.object.v1.finalized" in event_type
    assert "test_bucket_for_storage" in bucket
    assert "new_blob_uploaded" in name
    assert metageneration == 1
    assert "2021-10-10 00:00:00.000000Z" in timeCreated
    assert "2021-11-11 00:00:00.000000Z" in updated

What's next

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