错误: 无法解析‘ core-js/es7/response’in’node_module@angle-devkit build-angle src angle-cli-files 模型中的‘ core-js/es7/response’

小开

最佳答案

You should install core-js@2.5.x that contains this file/module. See preset-env docs.

Also note, however, that this is a very old version with known issues and is unsupported. From the module itself:

"core-js@<3.23.3 is no longer maintained and not recommended for usage due to the number of issues. Because of the V8 engine whims, feature detection in old core-js versions could cause a slowdown up to 100x even if nothing is polyfilled. Some versions have web compatibility issues. Please, upgrade your dependencies to the actual version of core-js."

Please consider using one of the better solutions below.

小开

The version 3.0 of core-js has some breaking changes:

https://github.com/zloirock/core-js/blob/master/docs/2019-03-19-core-js-3-babel-and-a-look-into-the-future.md

You should find a line similar to this in one of your files: import "core-js/es7/reflect";

Change it to this: import "core-js/proposals/reflect-metadata";

小开

If you'd like to use version 3.0, you can add the a path to your tsconfig.json file.

{
"compilerOptions": {
...
"paths": {
"core-js/es7/reflect": [
"node_modules/core-js/proposals/reflect-metadata"
]
}
}
}

Note: You need check the node_modules/core-js/proposals/reflect-metadata relative path and correct it if needed in your project structure.

小开

I found possible answer. You have core-js version 3.0, and this version doesn't have separate folders for ES6 and ES7; that's why the application cannot find correct paths.

To resolve this error, you can downgrade the core-js version to 2.5.7. This version produces correct catalogs structure, with separate ES6 and ES7 folders.

To downgrade the version, simply run:

npm i -S core-js@2.5.7

小开

The tsconfig.json solution from @medeni works, but don't copy the path before checking it by yourself. For me it had to be:

"paths": {
"core-js/es7/reflect": ["../node_modules/@angular-devkit/build-angular/node_modules/core-js/proposals/reflect-metadata"]
}

the ../ is because tsconfig.json is extended by src/tsconfig.app.json or src/tsconfig.spec.json, so /src is the working directory.

note: I am using Angular CLI 8.1.0

小开

I fixed it by adding this import: import 'core-js/proposals/reflect-metadata'; in my polyfills.ts file

/** Evergreen browsers require these. **/
// Used for reflect-metadata in JIT. If you use AOT (and only Angular decorators), you can remove.
import 'core-js/proposals/reflect-metadata';

Make sure you have the latest core-js update and everything should work.

小开

For Angular 8 (source):

Angular CLI 8.0+ manages the required Angular polyfills directly and projects will not require a direct dependency on core-js (assuming an application does not manually include additional core-js polyfills).

I've resolved by:

removing core-js from my package.json dependencies
removing import 'core-js/es7/reflect'; from my test.ts

小开

In my case , i just changed -->

import 'core-js/es6/reflect';
import 'core-js/es7/reflect';

to

import 'core-js/es/reflect';

and it worked..

小开

Removing the number at the end of 'es' in the path, like 'core-js/es/reflect' worked also for me.

For EX: import 'core-js/es7/reflect'; was changed to import 'core-js/es/reflect';

小开

For angular latest version (currently -> 9) ,

compatible core-js version is "core-js": "~2.5.0".

step 1) Delete Node modules.

step 2) In package.json file, write "core-js": "~2.5.0" in dependecies object.

step 3) npm install

then It will work perfectly fine

小开

For Angular 7

From package.json remove:

"core-js": "3.6.5",

because it is part of the Angular package.

小开

I solved the problem by removing the number at the end of "es" in the path as in response to Module not found: Error: Can't resolve 'core-js/es7/reflect