George Kalpakas 07ea6cf582 fix(ngcc): avoid error due to circular dependency in EsmDependencyHost (#34512)
Previously, there was circular dependency between `ngcc/src/utils.ts`,
`ngcc/src/dependencies/dependency_host.ts` and
`ngcc/src/dependencies/esm_dependency_host.ts`. More specifically,
`utils.ts` would [import from `esm_dependency_host.ts`][1], which would
[import from `dependency_host.ts`][2], which would in turn
[import from `utils.ts`][3].

This might be fine in some environments/module formats, but it can cause
unclear errors in the transpiled CommonJS/UMD format (given how Node.js
handles [cycles in module resolution][4]).
(An example error can be found [here][5].)

This commit fixes the problem by moving the code that depends on
`EsmDependencyHost` out of `utils.ts` and into a dedicated file under
`dependencies/`. It also converts the `createDtsDependencyHost()`
function to a class for consistency with the rest of the
`DependencyHost`s.

[1]: https://github.com/angular/angular/blob/18d89c9c8/packages/compiler-cli/ngcc/src/utils.ts#L10
[2]: https://github.com/angular/angular/blob/18d89c9c8/packages/compiler-cli/ngcc/src/dependencies/esm_dependency_host.ts#L10
[3]: https://github.com/angular/angular/blob/18d89c9c8/packages/compiler-cli/ngcc/src/dependencies/dependency_host.ts#L9
[4]: https://nodejs.org/api/modules.html#modules_cycles
[5]: https://circleci.com/gh/angular/angular/577581

PR Close #34512
2020-01-08 15:00:50 -08:00
..
2019-01-11 11:15:59 -08:00

Angular

The sources for this package are in the main Angular repo. Please file issues and pull requests against that repo.

Usage information and reference details can be found in Angular documentation.

License: MIT