feat(PubSub): Add samples to create topics and subscriptions with SMT support

[Hectorhammett]

Added the samples for PHP's PubSub library to create both Topics and Subscriptions with SMT.

b/427316648

[snippet-bot]

Here is the summary of changes.

You are about to add 2 region tags.

• pubsub/api/src/create_subscription_with_smt.php:25, tag pubsub_create_subscription_with_smt
• pubsub/api/src/create_topic_with_smt.php:25, tag pubsub_create_topic_with_smt

---

This comment is generated by snippet-bot.
If you find problems with this result, please file an issue at:
https://github.com/googleapis/repo-automation-bots/issues.
To update this comment, add snippet-bot:force-run label or use the checkbox below:

• Refresh this comment

[gemini-code-assist]

Summary of Changes

Hello @Hectorhammett, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request enhances the Google Cloud Pub/Sub PHP client library documentation by adding practical code samples. These samples illustrate how to configure and create Pub/Sub topics and subscriptions with Single Message Transforms (SMT) enabled, using JavaScript User-Defined Functions (UDFs) to modify message payloads. This provides developers with clear guidance on implementing server-side message transformations, streamlining data processing workflows directly within Pub/Sub.

Highlights

• New PHP Samples for SMT: Added new PHP samples for Google Cloud Pub/Sub demonstrating Single Message Transforms (SMT).
• SMT Subscription Sample: Introduced a sample to create a Pub/Sub subscription with an SMT, including a JavaScript User-Defined Function (UDF) for message transformation.
• SMT Topic Sample: Provided a sample to create a Pub/Sub topic with an SMT, also featuring a JavaScript UDF for message transformation.
• PHPUnit Tests: Included corresponding PHPUnit test cases to validate the correct creation of SMT-enabled topics and subscriptions.
• Dependency and Test Setup: Set up a composer.json and phpunit.xml.dist for the new pubsub/smt directory to manage dependencies and testing.

Using Gemini Code Assist

The full guide for Gemini Code Assist can be found on our documentation page, here are some quick tips.

Invoking Gemini

You can request assistance from Gemini at any point by creating a comment using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands on the current page.

Feature	Command	Description
Code Review	/gemini review	Performs a code review for the current pull request in its current state.
Pull Request Summary	/gemini summary	Provides a summary of the current pull request in its current state.
Comment	@gemini-code-assist	Responds in comments when explicitly tagged, both in pull request comments and review comments.
Help	/gemini help	Displays a list of available commands.

Customization

To customize Gemini Code Assist for GitHub experience, repository maintainers can create a configuration file and/or provide a custom code review style guide (such as PEP-8 for Python) by creating and adding files to a .gemini/ folder in the base of the repository. Detailed instructions can be found here.

Limitations & Feedback

Gemini Code Assist may make mistakes. Please leave feedback on any instances where its feedback is incorrect or counter productive. You can react with 👍 and 👎 on @gemini-code-assist comments. If you're interested in giving your feedback about your experience with Gemini Code Assist for Github and other Google products, sign up here.

You can also get AI-powered code generation, chat, as well as code reviews directly in the IDE at no cost with the Gemini Code Assist IDE Extension.

Footnotes

1. Review the Privacy Notices, Generative AI Prohibited Use Policy, Terms of Service, and learn how to configure Gemini Code Assist in GitHub here. Gemini can make mistakes, so double check it and use code with caution. ↩

[gemini-code-assist]

Code Review

This pull request adds new PHP samples for creating Pub/Sub topics and subscriptions with Single Message Transform (SMT) support. The overall implementation is good, but I've found a few issues that need to be addressed. There's a critical issue in the subscription creation sample where an incorrect method is used. Additionally, there are some minor issues in the test files, such as an undefined variable and misleading error messages, and a configuration issue in phpunit.xml.dist. I've provided detailed comments and suggestions for each of these points.