Add isArray and isMap to tree-agent context

[noencke]

This gives the LLM an alternative to Array.isArray and instanceof Map that will work on our node types, since Array.isArray does not work with our non-pojo array classes.

The provided functions also work for JS arrays and Maps, so the LLM doesn't have to distinguish between when to use the built-in Array.isArray vs. when to use our provided isArray helper - it can always use the latter. This also gives us the option in the future to force it to use ours by making Array.isArray error within the boundaries of the eval.

This also adds some explicit tests in SharedTree for Array.isArray support.

[Copilot]

Pull Request Overview

This PR adds isArray and isMap helper functions to the tree-agent context, providing LLM-friendly alternatives to Array.isArray and instanceof Map that work correctly with Fluid Framework's custom node types. These helpers also support native JavaScript arrays and Maps, allowing consistent usage patterns in LLM-generated code.

Key changes:

• Added isArray and isMap helper functions to the Context interface and implementation
• Updated prompt generation to include documentation for these new helpers
• Added comprehensive test coverage for both helpers

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
packages/framework/tree-agent/src/api.ts	Adds isArray and isMap method signatures to the Context interface
packages/framework/tree-agent/src/agent.ts	Implements isArray and isMap helpers using NodeKind checks for TreeNode instances
packages/framework/tree-agent/src/prompt.ts	Updates prompt generation to document the new helpers and improves example type name extraction
packages/framework/tree-agent/src/test/agent.spec.ts	Adds test coverage for isArray and isMap helpers, removes obsolete test and eslint directives
packages/framework/tree-agent/src/test/__snapshots__/prompt.md	Updates snapshot to reflect new helper documentation and improved examples
packages/dds/tree/src/test/simple-tree/node-kinds/arrayNode.spec.ts	Documents that custom array nodes don't pass Array.isArray

[Copilot]

Missing space after || operator. Should be || !context.isArray for consistency with coding standards.

[github-actions]

🔗 Found some broken links! 💔

Run a link check locally to find them. See
https://github.com/microsoft/FluidFramework/wiki/Checking-for-broken-links-in-the-documentation for more information.

linkcheck output

> fluid-framework-docs-site@0.0.0 ci:check-links /home/runner/work/FluidFramework/FluidFramework/docs
> start-server-and-test "npm run serve -- --no-open" 3000 check-links

1: starting server using command "npm run serve -- --no-open"
and when url "[ 'http://127.0.0.1:3000' ]" is responding with HTTP status code 200
running tests using command "npm run check-links"


> fluid-framework-docs-site@0.0.0 serve
> docusaurus serve --no-open

[SUCCESS] Serving "build" directory at: http://localhost:3000/

> fluid-framework-docs-site@0.0.0 check-links
> linkcheck http://localhost:3000 --skip-file skipped-urls.txt

 ELIFECYCLE  Command failed with exit code 1.