Question: problems with integrating ng-packagr generated package with Angular CLI app: Module not found

[dragonflypl]

Here's a repo that reproduces it: https://github.com/dragonflypl/ng-packagr-issue

1. I've create a simple package logging. npm run build generates the library + does npm pack
2. Then I generated fooGui with Angular CLI and installed library it via npm run consume that installs tgz
3. Running npm run build from fooGui throws:

ERROR in ./src/app/app.component.ngfactory.js
Module not found: Error: Can't resolve 'logging/src/modules/logging/logger/index' in 'C:\XXX\dev\ng-packagr-issue\fooGui\src\app'
resolve 'logging/src/modules/logging/logger/index' in 'C:\XXX\dev\ng-packagr-issue\fooGui\src\app'
  Parsed request is a module
  using description file: C:\XXX\dev\ng-packagr-issue\fooGui\package.json (relative path: ./src/app)
    Field 'browser' doesn't contain a valid alias configuration
  after using description file: C:\XXX\dev\ng-packagr-issue\fooGui\package.json (relative path: ./src/app)
    resolve as module
      C:\XXX\dev\ng-packagr-issue\fooGui\src\app\node_modules doesn't exist or is not a directory
      C:\XXX\dev\ng-packagr-issue\fooGui\src\node_modules doesn't exist or is not a directory
      C:\XXX\dev\ng-packagr-issue\node_modules doesn't exist or is not a directory
      C:\XXX\dev\node_modules doesn't exist or is not a directory
      C:\XXX\node_modules doesn't exist or is not a directory
      C:\node_modules doesn't exist or is not a directory
      looking for modules in C:\XXX\dev\ng-packagr-issue\fooGui\node_modules
        using description file: C:\XXX\dev\ng-packagr-issue\fooGui\package.json (relative path: ./node_modules)
          Field 'browser' doesn't contain a valid alias configuration
        after using description file: C:\XXX\dev\ng-packagr-issue\fooGui\package.json (relative path: ./node_modules)
          using description file: C:\XXX\dev\ng-packagr-issue\fooGui\node_modules\logging\package.json (relative path: ./src/modules/logging/logger/index)
            no extension
              Field 'browser' doesn't contain a valid alias configuration
              C:\XXX\dev\ng-packagr-issue\fooGui\node_modules\logging\src\modules\logging\logger\index doesn't exist
            .ts
              Field 'browser' doesn't contain a valid alias configuration
              C:\XXX\dev\ng-packagr-issue\fooGui\node_modules\logging\src\modules\logging\logger\index.ts doesn't exist
            .js
              Field 'browser' doesn't contain a valid alias configuration
              C:\XXX\dev\ng-packagr-issue\fooGui\node_modules\logging\src\modules\logging\logger\index.js doesn't exist
            as directory
              C:\XXX\dev\ng-packagr-issue\fooGui\node_modules\logging\src\modules\logging\logger\index doesn't exist

Any idea what I did wrong or it is a bug somewhere?

[dragonflypl]

I've found the culprit: in public api file, I have:

export * from './src/modules/logging/logger'; that access index.ts.

When I replaced it with explicit it with explicit exports:

export * from './src/modules/logging/logger/logger.service';
export * from './src/modules/logging/logger/log-level.enum';

then it works. Any idea why?

[dherges]

Hi @dragonflypl,

I don't know why it happens.

1. There are known issues with TypeScript barrels TypeScript barrels break build #195. Here are some specific and more precise issues (bug(compiler-cli): metadata resolution error when generating flat module with reference in re-export angular/angular#20931, Bundled metadata does not reflect metadata lowering. angular/angular#21082, [AoT] Bundled metadata does not reflect metadata lowering // [PREV: Packaged library is not working in AOT mode] #382) that seem to be related to barrel files which is why I'd recommend to not use index.ts files.

Can you confirm if either of the above and, if yes, which is your issue? That'll help to put up a good repro and then try to get a fix in.

---

Info: user runs:

$ cd path/to/library-sources
$ npm pack dist
$ cd path/to/cli-app-project
$ npm install ../logging/dist/logging-1.0.0-rc.1.tgz
$ ng build --prod

[deebloo]

The issue with barrels isn't usually barrels themselves but it is easy to cause a circular dependency with them which is often times what causes this issue,

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