exported default function might break AOT

[schmitch]

I'm submitting a ...

[ ] Regression (behavior that used to work and stopped working in a new release)
[X] Bug report 
[ ] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead see https://github.com/angular/angular/blob/master/CONTRIBUTING.md#question

Current behavior

Below code fails with:

ERROR in Cannot read property 'text' of undefined

ERROR in ./src/main.ts
Module not found: Error: Can't resolve './$$_gendir/app/app.module.ngfactory' in 'HOME/demo-app/src'
 @ ./src/main.ts 4:0-74
 @ multi ./src/main.ts

Expected behavior

That code:

export default function () {

  const mainRoutes = [
    {name: 'a', abstract: true, component: 'main'},

    {name: 'a.welcome', url: '/welcome', component: 'welcome'}
  ];

  return mainRoutes;

}

should compile fine under AOT. it's actually a simple array. removing the unncessary variable, should work, too.

Minimal reproduction of the problem with instructions

Create a file called states.ts somewhere in your source folder (does not need to be imported) and insert the code above.
Run ng build --prod.

What is the motivation / use case for changing the behavior?

Please tell us about your environment

Angular version: 4.2.2

Browser:

• Chrome (desktop) version XX
• Chrome (Android) version XX
• Chrome (iOS) version XX
• Firefox version XX
• Safari (desktop) version XX
• Safari (iOS) version XX
• IE version XX
• Edge version XX

For Tooling issues:

• Node version: v8.1.1
• Platform: Mac OS X 11.11

Others:
Might be related, but different error message: #11402
Looks like that works:

export default [
    {name: 'a', abstract: true, component: 'main'},

    {name: 'a.welcome', url: '/welcome', component: 'welcome'}
];

which however is also default

[hansl]

This issue seems to be a CLI issue. Please file it at http://github.com/angular/angular-cli/issues/new. This repo is for the Angular framework itself. Thanks!

[schmitch]

@hansl how can this be a cli error?

this is the full output when running ngc:

schmitch:~/projects/envisia/erp/loki/ui$ ./node_modules/.bin/ngc 
TypeError: Cannot read property 'text' of undefined
    at exportedIdentifierName (/Users/schmitch/projects/envisia/erp/loki/ui/node_modules/@angular/tsc-wrapped/src/collector.js:242:44)
    at exportedName (/Users/schmitch/projects/envisia/erp/loki/ui/node_modules/@angular/tsc-wrapped/src/collector.js:244:53)
    at /Users/schmitch/projects/envisia/erp/loki/ui/node_modules/@angular/tsc-wrapped/src/collector.js:343:38
    at visitEachNode (/Users/schmitch/projects/envisia/erp/loki/ui/node_modules/typescript/lib/typescript.js:14785:30)
    at Object.forEachChild (/Users/schmitch/projects/envisia/erp/loki/ui/node_modules/typescript/lib/typescript.js:14959:24)
    at MetadataCollector.getMetadata (/Users/schmitch/projects/envisia/erp/loki/ui/node_modules/@angular/tsc-wrapped/src/collector.js:280:12)
    at CompilerHost.getMetadataFor (/Users/schmitch/projects/envisia/erp/loki/ui/node_modules/@angular/compiler-cli/src/compiler_host.js:199:51)
    at StaticSymbolResolver.getModuleMetadata (/Users/schmitch/projects/envisia/erp/loki/ui/node_modules/@angular/compiler/bundles/compiler.umd.js:25453:62)
    at StaticSymbolResolver._createSymbolsOf (/Users/schmitch/projects/envisia/erp/loki/ui/node_modules/@angular/compiler/bundles/compiler.umd.js:25259:46)
    at StaticSymbolResolver.getSymbolsOf (/Users/schmitch/projects/envisia/erp/loki/ui/node_modules/@angular/compiler/bundles/compiler.umd.js:25240:14)
Compilation failed

I tought the compiler lies in this repo...

[chuckjaz]

The referenced PR will fix the crash but will but this code will still not be supported.

First, we don't support referencing default functions in AOT metadata. We are working on this but his will not be resolved until sometime after 5.0.

Second, the function is not a simple function that we require. I have a document that describes the limitations on TypeScript syntax we support in metadata here https://gist.github.com/chuckjaz/65dcc2fd5f4f5463e492ed0cb93bca60. We are also lifting many of these restrictions for 5.0 but the simple (or macro) function limitation will still be there for 5.0.

Changing this to

export function mainRoutes() {
  return [
    {name: 'a', abstract: true, component: 'main'},
    {name: 'a.welcome', url: '/welcome', component: 'welcome'}
  ];
}

and then importing {mainRoutes} will work.

We must be able to determine the value of the routes at compile time and we cannot support all the features of JavaScript and TypeScript during this evaluation. We are continually improving this and have significant improvements coming.

[schmitch]

well I think no matter if supported or not. having at least a sane error message would help ;)

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