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
This commit is contained in:
George Kalpakas
2020-01-08 19:10:25 +02:00
committed by Alex Rickabaugh
parent c38195f59e
commit 07ea6cf582
7 changed files with 39 additions and 23 deletions

View File

@ -11,9 +11,9 @@ import {absoluteFrom, getFileSystem, relativeFrom} from '../../../src/ngtsc/file
import {runInEachFileSystem} from '../../../src/ngtsc/file_system/testing';
import {loadTestFiles} from '../../../test/helpers';
import {createDependencyInfo} from '../../src/dependencies/dependency_host';
import {DtsDependencyHost} from '../../src/dependencies/dts_dependency_host';
import {EsmDependencyHost, hasImportOrReexportStatements, isStringImportOrReexport} from '../../src/dependencies/esm_dependency_host';
import {ModuleResolver} from '../../src/dependencies/module_resolver';
import {createDtsDependencyHost} from '../../src/utils';
runInEachFileSystem(() => {
@ -160,7 +160,7 @@ runInEachFileSystem(() => {
expect(jsDeps.missing.has(relativeFrom('./internal-typings'))).toBeTruthy();
// Typings mode will pick up `internal-typings.d.ts` dependency
const dtsHost = createDtsDependencyHost(fs);
const dtsHost = new DtsDependencyHost(fs);
const dtsDeps = createDependencyInfo();
dtsHost.collectDependencies(_('/external/index.d.ts'), dtsDeps);
expect(dtsDeps.dependencies.size).toEqual(2);