Expose emitted module specifiers on AMD outfile emit

Search Terms

amd outfile module specifier

Suggestion

Currently when utilising the compiler APIs to emit as AMD to a single outfile, the emitted module specifier in the outfile is not exposed, but does not match the source file SourceFile.fileName or any other attribute.

It appears that there are internals of the TypeScript emitter which determine the module specifier that is included output. For example, if given /foo/bar/baz.ts and /foo/qat/qux.ts being part of the same program, when emitted as AMD in a single bundle the module specifier, the outfile will define() a module named bar/baz and qat/qux. It appears that the algorithm used looks for the common root and removes the extension to determine the module specifier.

Use Cases

When loading the bundle with an AMD loader, knowing what a module specifier is in the outfile is needed to be able to specify a module to load in a require() statement. So if we were automating a custom build, outputting a "bundle" and determining which module to require() to bootstrap the application, we have to "guess" and hope that the emitter doesn't change its algorithm of determining the module specifiers.

Examples

I'm not totally sure, but a public API that would take a SourceFile[] and provide back a string[] array of module specifiers. This could be used in Host.writeFile() to determine what module specifiers are contained in the written file.

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, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

Start by tracing the TypeScript emitter internals that determine AMD module specifiers when emitting to a single outfile. Review the compiler API around SourceFile.fileName, SourceFile[] and Host.writeFile, then define how the emitted specifiers should be exposed. Done means callers can obtain the exact specifiers contained in the written bundle without guessing.