JS: Support Promise.try and Array.prototype.with

[asgerf]

Adds support for Promise.try and Array.prototype.with

[Copilot]

Pull Request Overview

This PR adds support for data flow tracking through two JavaScript methods: Promise.try and Array.prototype.with. These are modern JavaScript features that enable better promise handling and immutable array operations respectively.

• Implements flow summaries for Promise.try to track data flow through promise creation and execution
• Implements flow summaries for Array.prototype.with to track data flow through immutable array updates
• Adds comprehensive test cases to verify data flow behavior for both methods

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
javascript/ql/test/library-tests/TripleDot/promise-try.js	Test cases for Promise.try data flow tracking
javascript/ql/test/library-tests/TripleDot/array-with.js	Test cases for Array.prototype.with data flow tracking
javascript/ql/src/change-notes/2025-09-16-promise-try-array-with.md	Release notes documenting the new features
javascript/ql/lib/semmle/javascript/internal/flow_summaries/Promises.qll	Flow summary implementation for Promise.try
javascript/ql/lib/semmle/javascript/internal/flow_summaries/FlowSummaryUtil.qll	Utility function to generate argument positions
javascript/ql/lib/semmle/javascript/internal/flow_summaries/Arrays.qll	Flow summary implementation for Array.prototype.with

[Napalys]

Just a quick question for my understanding. We would not have flow if a lambda would have more then 10 arguments?
Also what happens if we have ...args(arbitrary number of arguments), will it work?

[asgerf]

Correct on both accounts

[Napalys]

Looks great 👍 , I have just a small question so I would understand better.