Plugin crashes when an other plugin generates a deferred asset

[Septh]

• Version: 2.0.4
• Rollup Version: 2.61.1
• Operating System and version (if applicable):
• Node Version (if applicable):
• Does it work with tsc (if applicable):

According to Rollup's documentation on plugin development, when calling this.emitFile():

It is possible to defer setting the source via this.setAssetSource(referenceId, source) to a later time

However, when doing so, rollup-plugin-ts crashes with:

[!] (plugin Typescript) TypeError: The "path" argument must be of type string. Received undefined
TypeError [ERR_INVALID_ARG_TYPE]: The "path" argument must be of type string. Received undefined
    at validateString (internal/validators.js:120:11)
    at Object.normalize (path.js:1005:5)
    at ensurePosixReturnValue (/home/runner/rollup-plugin-ts-repro/node_modules/crosspath/dist/cjs/index.js:45:64)
    at Object.normalize (/home/runner/rollup-plugin-ts-repro/node_modules/crosspath/dist/cjs/index.js:93:20)
    at Object.generateBundle (/home/runner/rollup-plugin-ts-repro/node_modules/rollup-plugin-ts/dist/cjs/index.js:8528:69)
    at /home/runner/rollup-plugin-ts-repro/node_modules/rollup/dist/shared/rollup.js:22681:25

Reproduction

I have made a repl here : https://replit.com/@Septh/rollup-plugin-ts-repro#rollup.config.js

Two things to note:

1. if you swap the order of the plugins, the build completes because then myPlugin has a chance of setting the source of the asset before it gets to rollup-plugin-ts.
2. if you use name instead of fileName in this.emitFile(), then the build completes whatever the order of the plugins.

Expected Behavior

No crash.

Actual Behavior

Crash.

[wessberg]

Hey there. Thanks for reporting it. A test case has been written, and this has been fixed in v2.0.5