getFileName returns incorrect result with multiple outputs

[LarsDenBakker]

• Rollup Version: v1.31.0 & v2.2.0
• Operating System (or Browser): OS X
• Node Version (if applicable): 10
• Link to reproduction (IMPORTANT, read below): https://repl.it/repls/MetallicMinorCareware

Expected Behavior

When using this.getFileName on a manually created chunk, I don't get the correct filename with multiple build outputs. In generateBundle for both phases, I get the filename of the last output.

I set the output to directory, since the REPL doesn't seem to support multiple outputs?

Actual Behavior

I get the same same file name for both phases.

[lukastaegert]

Please do not forget to add the Rollup version to the template. I assume it is the latest but once someone gets to looking into this, who knows what latest was when you created the issue.

[LarsDenBakker]

Sorry about that, I got this with rollup v2.2.0 locally and the v1.31. loaded by the repl. I updated the original issue.

[lukastaegert]

Ok, this one is nastier than I thought. Basically it is caused by an unfortunate design decision where chunk objects are reused for each output. The long term goal is to refactor everything so that this is no longer the case, but the question is how long this will take. This would also fix this issue. But I am not sure how to provide a short-term fix.

[LarsDenBakker]

Thanks for looking into it. For now I am able to work around it by using two separate output plugins.

[lukastaegert]

Fix at #3645, which will finally move chunk creation to the output generation phase and make manualChunks, inlineDynamicImports and preserveModules output options.

[LarsDenBakker]

Thats great! It enables a lot of possibilities.