Can't resolve modules from custom path

[tbnovaes]

🐞 bug report

Description

When trying to serve the app using custom paths on tsconfig.json for some libs I created everything works fine, however, when trying to build it using AOT, I get multiple errors:

ERROR in ./src/app/app.module.ngfactory.js
Module not found: Error: Can't resolve 'some_module' in 'some_path '

Works fine when AOT is set to false.

Additional Information

Here is my tsconfig.json

{
  "compileOnSave": false,
  "compilerOptions": {
    "baseUrl": "./",
    "outDir": "./dist/out-tsc",
    "sourceMap": true,
    "declaration": false,
    "module": "esnext",
    "moduleResolution": "node",
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "allowSyntheticDefaultImports": true,
    "esModuleInterop": true,
    "importHelpers": true,
    "target": "es2015",
    "typeRoots": [
      "node_modules/@types"
    ],
    "lib": [
      "es2018",
      "dom"
    ],
    "paths": {
      //Env
      "@env/*": ["src/environments/*"],

      //Libs
      "@lib/pipes": ["dist/pipes"],
      "@lib/pipes/*": ["dist/pipes/*"],
      "@lib/utils": ["dist/utils"],
      "@lib/utils/*": ["dist/utils/*"],
      "@lib/directives": ["dist/directives"],
      "@lib/directives/*": ["dist/directives/*"],
      "@lib/models": ["dist/models"],
      "@lib/models/*": ["dist/models/*"],
      "@lib/websocket": ["dist/websocket"],
      "@lib/websocket/*": ["dist/websocket/*"],
      "@lib/intl-phone-input": ["dist/intl-phone-input"],
      "@lib/intl-phone-input/*": ["dist/intl-phone-input/*"]
    }
  }
}

🌍 Your Environment

**Angular Version:**
Angular CLI: 8.0.0
Node: 12.3.1
OS: darwin x64
Angular: 
... 

Package                      Version
------------------------------------------------------
@angular-devkit/architect    0.800.0
@angular-devkit/core         8.0.0
@angular-devkit/schematics   8.0.0
@schematics/angular          8.0.0
@schematics/update           0.800.0
rxjs                         6.4.0

[tbnovaes]

@trotyl @jotatoledo I haven't understand the thumbs down... if you know a solution/workaround would you please be able to post it here, so we can close the issue?

[jotatoledo]

Provide a repro...

[tbnovaes]

@jotatoledo here is a repo reproducing the issue:

https://github.com/tbnovaes/CustomPathIssue

npm install
npm run build => will build the lib and app

The steps I followed to reproduce it were:

1- Create a new project with the cli
2- Create a new library with the cli
3- Modify the tsconfig.json to use @lib/my-lib as path
3- Import the library on app.module.ts
4- Build the library
5- Build the app with --prod flag
6- Error happens around 90% of the build process

ng build my-lib && ng build --prod

Building Angular Package
Building entry point 'my-lib'
Compiling TypeScript sources through ngc
Bundling to FESM2015
Bundling to FESM5
Bundling to UMD
Minifying UMD bundle
Copying declaration files
Writing package metadata
Built my-lib
Built Angular Package!
 - from: {{some path}}
 - to:   {{some path}}
                                                                                 
Date: 2019-06-12T13:45:35.209Z
Hash: fc882ed9bcac2cf0041f
Time: 18548ms
chunk {0} runtime-es5.741402d1d47331ce975c.js (runtime) 1.41 kB [entry] [rendered]
chunk {1} main-es5.6b779598a3cbb89134e0.js (main) 242 kB [initial] [rendered]
chunk {2} polyfills-es5.943113ac054b16d954ae.js (polyfills) 111 kB [initial] [rendered]
chunk {3} styles.09e2c710755c8867a460.css (styles) 0 bytes [initial] [rendered]

ERROR in ./src/app/app.module.ngfactory.js
Module not found: Error: Can't resolve 'my-lib' in {{some path}}
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! custom-path-issue@0.0.0 build: `ng build my-lib && ng build --prod`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the custom-path-issue@0.0.0 build script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

EDIT:
changing the @lib/my-lib to only my-lib on tsconfig.json and the same with the import on app.module.ts allows it to compile without errors

EDIT 2:
the issue just happen when importing the my-lib.module.ts, if importing any other file from the public_api.ts, compilation works just fine either with @lib/my-lib and my-lib

[alxhub]

Changing the path mapping is not enough to change the entrypoint name of the library. You also have to edit package.json for projects/my-lib/package.json and change the name there. Then your repro will work.

Hope this helps!