Does the `tsc` command accept .d.ts files?

Question

I have a .d.ts file, and would like to compile it down to a .js file. Is this possible using the tsc command?

I know that the tsc command can take any .ts file and then compile it down .js file (I have tested this). However, I couldn't get it to take a .d.ts file as an input since it did not output any .js file for me.

I have tried to play around with tsconfig.json and this how my file looks like at the moment:

{
    "compilerOptions": {
        "target": "es5",
        "module": "commonjs",
        "sourceMap": true,
        "outDir": "ali_output_javascript"
    }
}

I also know the following about .d.ts and .ts files. Typescript declaration files (.d.ts) describe the shape of a JavaScript file. It allows you to use existing JavaScript code in TypeScript without having to write all the code in TypeScript. Typescript files (.ts) is just the standard file extension when writing in typescript.

From this medium article (https://medium.com/jspoint/typescript-compilation-the-typescript-compiler-4cb15f7244bc), it does say that TypeScript compilation looks for file extensions .ts and .d.ts:

Normally, you would use files or include option and provide file paths or glob patterns to include TypeScript files in the compilation process. However, you can drop the .ts extension from the glob pattern and let the TypeScript compiler search for the input files. When a glob pattern doesn’t have a file extension, TypeScript looks for the files ending with .ts or .d.ts extension in the directory pointed by the glob pattern. The .d.ts file is a TypeScript declaration file, we have discussed this file type in the Declaration Files lesson (coming soon). When the allowJS compiler-option is set to true, the TypeScript will also search for .js files as well.

Please let me know if you any suggestions, and thank you for your time.

Answer 1

You misunderstood what .d.ts files are.

They are not supposed to be transpiled into .js files. Instead, .ts files are supposed to be transpiled into .js files and .d.ts files for strong typing in a JavaScript IDE, or for further use into a TypeScript project.

Also, .d.ts are not executable and cannot produce executable files as they are just empty shells with types. This is also know as ambient declaration, in TypeScript terms, which means "without implementation".