Fix delimiter handling in parser

[brettle]

If a response contained "--batch" (or if the server started using a delimiter other than "--batch"), the parser would get confused. This fixes that.

Note this does not fix the same issue with the binary parser nor a similar issue that could arise if a request contains "--xxxxxxxxxx".

[gemini-code-assist]

Summary of Changes

Hello @brettle, 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 robustness of the batch request parser by dynamically identifying the response delimiter, addressing issues where the parser would fail if the response content contained the default delimiter or if a different delimiter was used by the server. It also includes improved error handling for malformed responses and a minor regex update.

Highlights

• Dynamic Delimiter Detection: The parser in BatchRequests.js now dynamically extracts the batch delimiter from the response body using a regex (/\r?\n--.*/) instead of relying on a hardcoded --batch string. This makes the parser more resilient to variations in response formatting and prevents issues when the response content itself contains the default delimiter.
• Improved Error Handling: A new check has been added to ensure that a valid delimiter is found in the response. If no delimiter is detected, an Error is thrown with the message "Valid response value is not returned.", preventing further parsing issues with malformed responses.
• Regex Modernization: The regular expression used for extracting content within curly braces has been updated from {[S\s]+}/g to {.+}/gs. The s flag (dotAll) simplifies the pattern by allowing . to match newline characters, making it more concise and potentially more efficient.

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 in your pull request via creating an issue comment (i.e. comment on the pull request page) using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands.

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 issue 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 or fill out our survey to provide feedback.

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 correctly addresses an issue where a hardcoded batch delimiter could cause parsing failures. The change to dynamically detect the delimiter from the response is a great improvement. I've provided a few suggestions to enhance the code further, including fixing a critical issue with an undeclared variable that could pollute the global scope, improving an error message for better debuggability, and modernizing variable declarations for consistency.

[gemini-code-assist]

The variable check is assigned without being declared with const, let, or var. In JavaScript's non-strict mode, this implicitly creates a global variable, which can lead to unexpected behavior and conflicts with other parts of the application.

It should be declared with const since its value is not changed after assignment.

Suggested change

	check = d_.match(/\r?\n--.*/);
	const check = d_.match(/\r?\n--.*/);

[gemini-code-assist]

The error message "Valid response value is not returned." is a bit generic. A more descriptive message would make debugging easier if this error is ever encountered. Consider specifying what was not found to provide more context to the developer.

Suggested change

	throw new Error("Valid response value is not returned.");
	throw new Error("Could not find batch response delimiter.");

[gemini-code-assist]

While much of the file uses var, this new block of code introduces const. To be consistent with modern JavaScript (ES6+) and to improve code clarity by using block-scoping, it would be better to use let instead of var for variables that are reassigned.

Using let is generally preferred over var to avoid issues with hoisting and to limit a variable's scope to the block in which it's defined.

Suggested change

	var regex, temp;
	let regex, temp;