Features

Cross-cutting capabilities that span multiple subsystems. Each page below traces one user-facing feature through the parser, checker, transformer, and emitter (and language service when relevant) so you can see how the layers cooperate.

Feature	Page	Spans
JSX / TSX	jsx	scanner, parser, checker, transformers/jsx.ts
Decorators	decorators	parser, transformers/legacyDecorators.ts, transformers/esDecorators.ts
Module systems	modules	parser, moduleNameResolver, module transformers, emitter
Declaration emit (.d.ts)	declaration-emit	checker, transformers/declarations.ts, expressionToTypeNode.ts, emitter
JS / JSDoc support (allowJs/checkJs)	jsdoc-and-js	parser (JSDoc), binder (assignment kinds), checker (JS-aware), language service
Project references / tsc -b	project-references	commandLineParser, tsbuildPublic, builder
Language-service features	language-service-features	services (completions, hover, navigation), tsserver protocol
Refactors and code fixes	refactors-and-codefixes	services, textChanges, codefix and refactor providers

Other notable cross-cutting capabilities documented elsewhere:

• Module resolution — see systems/module-resolution.
• Watch and incremental compilation — see systems/watch-and-builder.
• Automatic Type Acquisition — see systems/automatic-type-acquisition.