Support tsc --build --noEmit

[segevfiner]

Suggestion

🔍 Search Terms

tsc --build --noEmit
build noEmit

List of keywords you searched for before creating this issue. Write them down here so that others can find this suggestion more easily and help provide feedback.

✅ Viability Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

⭐ Suggestion

Allow tsc --build --noEmit, the relevant types can be emitted to the tsbuildinfo for incremental building. This is very useful to allow type checking only for projects using project references and working with a bundler. e.g. A create-vue project, which currently has to resort to hackery such as vue-tsc --noEmit -p tsconfig.vitest.json --composite false which is not as accurate as type checking each project individually.

📃 Motivating Example

tsc --build --noEmit is now supported, allowing to only run type checking for projects using project references that don't also build types using tsc.

💻 Use Cases

Type checking only, for projects using other build tools than tsc but still using project references for each of configuration.

[sheetalkamat]

tsc --build --noEmit is supported unless a project references another project which would make it difficult to support since its depending on d.ts output file from the referenced project.

[segevfiner]

Note that referenced projects were not allowed to specify noEmit in TS<5, but they are allowed now, although the behavior in terms of type checking is unclear, seems like it skips them or something of that sort.

[thebanjomatic]

I encountered this problem as well recently. You can specify noEmit: true in the tsconfig.js, but you can't pass it via the command-line. Support for --emitDeclarationOnly was added in this PR: #51164 would it be reasonable to add --noEmit as well?

[david-alpert-nl]

I got here because I am attempting to run tsc --noEmit for type checking since my build tooling (vite) explicitly transpiles only and does not validate type consistency.

I find that tsc --noEmit does what I want but emits no progress while it's running. when I tried to add --verbose it says that the progress update is only supported with --build but that --build and --noEmit are not permitted together

tsc --verbose --noemit 
error TS5093: Compiler option '--verbose' may only be used with '--build'.

tsc --build --verbose --noemit
error TS5094: Compiler option '--noemit' may not be used with '--build'.