Experimental: Fast-emitting TS declaration for saved file (250-400ms to produce declaration)
Use either project's @babel/core / typescript (for declaration emit) or bundled ones (if not found)
Requirements
Babel 7.1+ (for upward rootMode)
Extension Settings
This extension contributes the following settings:
babel-compile-on-save.include: List of source file globs to transpile through babel. Something like [ "src/**/*.ts", "src/**/*.js" ]. Default [].
babel-compile-on-save.outDir: Output directory for transpiled files. E.g. build or similar. Setting to "" will place transpiled files next to the source file (Beware: may overwrite sourcefile if they have same extension, i.e. file.js -> file.js). Default build.
babel-compile-on-save.srcDir: Your src root directory. Used to calculate correct sourceFileName mapping from result sourcemap. Default src.
babel-compile-on-save.outExt: Output filename extension. Default .js. Possible choices: .mjs or .jsx (for react-native)
babel-compile-on-save.emitTSDeclaration: Emit TS declaration for transpiled file. Uses project's tsconfig.json for output paths. Ignores any errors. Suggested use is with project-wide tsc -w --noEmit background task which will produce errors. Default false.
babel-compile-on-save.emitTSDeclarationMap: Also emit declaration map. May be handy if use want to put isolatedModules: true into your main tsconfig.json (VSCode loads only this config), since you can't use both declaration (and declarationMap) and isolatedModules at same time. The extension will set internally isolatedModules to false when emitting declaration file on save. You can also have separate tsconfig.check.json (or whatever name) with isolatedModules: true and run background task with error reporting, but the problem here that vscode will hide errors related to isolatedModules setting when opening the file. For initial declaration generation for project i recommend to use separate tsconfig.build.json with isolatedModules turned off.
Sourcemaps
Sourcemap will be written when detected. Set sourceMap: true (or "inline") in babel.config.js or whatever you use for babel config file.
emitTSDeclaration
This feature mainly is to support TS monorepo scenarios compiled through babel and @babel/preset-typescript. With --emitDeclarationOnly the incremental compilation of typescript takes around ~6-10 seconds to finish on medium (or greater) sized projects. This is trying to workaround it by creating TS program with only one file and producing declaration for it only. The result is 250-400ms vs 6-10 seconds. Any errors will be ignored, so you need to have separate reporting channel: tsc -w --noEmit is pretty good example and fast.
