When set, instead of writing out a .js.map file to provide source maps, TypeScript will embed the source map content in the .js files. Although this results in larger JS files, it can be convenient in some scenarios. For example, you might want to debug JS files on a webserver that doesn't allow .map files to be served.

Mutually exclusive with sourceMap.

For example, with this TypeScript:

const helloWorld = "hi";
console.log(helloWorld);

const helloWorld = "hi";
console.log(helloWorld);

Converts to this JavaScript:

// @showEmit
const helloWorld = "hi";
console.log(helloWorld);

// @showEmit
const helloWorld = "hi";
console.log(helloWorld);

Then enable building it with inlineSourceMap enabled there is a comment at the bottom of the file which includes a source-map for the file.

// @inlineSourceMap
// @showEmit
const helloWorld = "hi";
console.log(helloWorld);

// @inlineSourceMap
// @showEmit
const helloWorld = "hi";
console.log(helloWorld);