JSII does not work properly with out of source build

[jpmartin2]

🐛 Bug Report

Affected Languages

This bug affects the generation of jsii assemblies

• TypeScript or Javascript
• Python
• Java
• .NET (C#, F#, ...)

General Information

• JSII Version: 0.22.0 (build 14afdde), typescript 3.7.5
• Platform: OSX 10.14.6

What is the problem?

When using the jsii options to override tsc outDir, no types are included in the .jsii assembly. This appears to be because of how the main file for the assembly is located:

jsii/packages/jsii/lib/assembler.ts

Line 74 in 591a5d9

const mainFile = path.resolve(this.projectInfo.projectRoot, this.projectInfo.types.replace(/\.d\.ts(x?)$/, '.ts$1'));

The use of the regex here to replace .d.ts with .ts assumes that the source file that created the typings file is in the same directory, which it won't be when tsc outDir is set. It seems jsii should either use the typings file as is (if that's possible), or have a separate configuration option for where the main source file is.

Verbose Log

No useful logs.

[jpmartin2]

Also, when mainFile here doesn't exist (as in this case because of the difference in path between the types file and the source file), there's no indication that anything went wrong, jsii just silently does nothing, which seems undesirable.

[RomainMuller]

Hey @jpmartin2 - thanks for reporting. This logic is definitely buggy after the introduction of support for customizing outDir.

Feel free to submit a pull request to correct that (it shouldn't be all too hard)... Otherwise, I'll try to get to it soon!