Add lib types for JSON.rawJSON, JSON.isRawJSON, and reviver context

[Vedant Madane (VedantMadane)]

Adds es2025.json.d.ts with type definitions for the Stage 4 TC39 proposal-json-parse-with-source which is part of ES2025 and has shipped in all major browsers and Node.js 22+.

Summary

• JSON.rawJSON(text) - creates a frozen RawJSON object for lossless JSON serialization (e.g. preserving large-integer precision)
• JSON.isRawJSON(value) - type-guard that narrows to RawJSON
• JSON.parse reviver context - overload whose reviver receives a third parameter { source: string } containing the original JSON source text of each primitive value

New files

File	Purpose
src/lib/es2025.json.d.ts	RawJSON interface + JSON augmentations
tests/cases/compiler/jsonParseWithSource.ts	Compiler test exercising all three APIs
tests/baselines/reference/jsonParseWithSource.*	Accepted baselines

Modified files

File	Change
src/lib/es2025.d.ts	/// <reference lib="es2025.json" />
src/lib/libs.json	Register es2025.json
src/compiler/commandLineParser.ts	Map es2025.json to its .d.ts

Fixes #61330

[René (Renegade334)]

which is part of ES2025

It isn't, MDN is wrong on this one. It has stage 4 approval, but is not yet in the latest draft: tc39/ecma262#3714

[TypeScript Bot (typescript-bot)]

With 6.0 out as the final release vehicle for this codebase, we're closing all PRs that don't fit the merge criteria for post-6.0 patches. If you think this was a mistake and this PR fits the post-6.0 patch criteria, please post to the 6.0 iteration issue with details (specifically, which PR and which patch criteria it satisfies).

Next steps for PRs:

• For crash bugfixes or language service improvements, PRs are currently accepted at the typescript-go repo
• Changes to type system behavior should wait until after 7.0, at which point mainline TypeScript development will resume in this repository with the Go codebase
• Library file updates (lib.d.ts etc) continue to live in this repo or the DOM Generator repo as appropriate

[Ryan Cavanaugh (RyanCavanaugh)]

Reopening as this is still valid (minus commandlineParser.ts)

[Copilot]

Pull request overview

Adds an ES2025-by-feature lib file to type the now-standard JSON.rawJSON, JSON.isRawJSON, and the JSON.parse reviver “source context” capability, and wires it into the es2025 lib plus compiler test coverage.

Changes:

• Introduces src/lib/es2025.json.d.ts defining RawJSON and augmenting JSON with rawJSON, isRawJSON, and a JSON.parse overload with a context parameter.
• References the new lib from src/lib/es2025.d.ts and registers es2025.json in src/lib/libs.json.
• Adds a compiler test (jsonParseWithSource.ts) and accepted baselines covering all three APIs.

Reviewed changes

Copilot reviewed 5 out of 7 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/lib/es2025.json.d.ts	Adds RawJSON and JSON API typings for the ES2025 JSON additions.
src/lib/es2025.d.ts	Includes the new es2025.json lib in the es2025 umbrella lib.
src/lib/libs.json	Registers es2025.json as an available by-feature lib.
tests/cases/compiler/jsonParseWithSource.ts	Compiler test exercising rawJSON, isRawJSON, and reviver context.
tests/baselines/reference/jsonParseWithSource.types	Baseline for type printing of the new APIs.
tests/baselines/reference/jsonParseWithSource.symbols	Baseline for symbol resolution including the new lib.
tests/baselines/reference/jsonParseWithSource.js	Baseline for JS emit.

[Andrii Furmanets (afurm)]

Approach / Design (nits):

1. JSON.rawJSON(text: string): RawJSON — The JSDoc documents the happy path but doesn't mention @throws for invalid input. Per the spec, JSON.rawJSON throws a SyntaxError when text is not a valid JSON primitive (not a string, number, boolean, or null) or is an object/array. Adding @throws {SyntaxError} would align with the existing JSON.parse JSDoc and help consumers handle error cases.

2. Test coverage for reviver context — The test file has one reviver test using a plain object. It might be worth adding cases for:

   • Array elements ("arr": [1, 2, 3]) — the context source for each element
   • Nested objects to verify the context is available at all levels

These are minor suggestions; the type definitions themselves look correct and match the Stage 4 proposal. The infrastructure changes (libs.json, commandLineParser.ts, es2025.d.ts) all look routine and correct.

[Ryan Cavanaugh (RyanCavanaugh)]

Andrii Furmanets (@afurm) future automated comments will result in a block; any automated activity we want to occur in this repo we will set up ourselves or already have

[Mulverine (MulverineX)]

Ryan Cavanaugh (@RyanCavanaugh) the commandLineParser.ts has since been removed, is there a reason this PR is not proceeding?

[aweebit]

The source property should be optional.

For each value produced by the parse, reviver is called with three arguments (the associated property key, the value, and a context object). If the property is unmodified and its value is primitive, the provided context object has a "source" property containing source text of the corresponding Parse Node.

Spec

[Vedant Madane (VedantMadane)]

Good catch — updated. context.source is now optional (source?: string), matching the spec: it's only present when the property is unmodified and the value is primitive. JSDoc, compiler tests, and baselines updated accordingly.