Add .js file extension to all in-project imports (#10994)

* add `.js` file extension to all in-project imports

* bundler adjustments

* remove postprocessing step

* fixup, script to detect build differences

* more fixes

* changeset

* adjust jest file resolution

* fix up wrong import in `batchHttpLink`

* add AreTheTypesWrong check

* minor action changes

* fixup

* use ascii format for attw

* update AreTheTypesWrong, use new `--pack` option

* add build comparison action

* omit minified comparison output

* trigger ci

* eslint configuration changes, temp custom eslint version

* trigger ci

* give workflows distincive names?

* revert to latest working CI build

* revert changes to workflows

* clean up newly merged imports

* fix command name

* adjust fetch-depth

* use runner temp dir

* dir tweaks

* temp file dir?

* fir argument

* logging

* more detail logging

* fix binary logic

* remove a bunch of logging again

* disable `set`

* partially reintroduce

* now, to find that last command...

* this seems like a good compromise

* bump the TS eslint parser to deal with TS 5.1

* apply feedback from review

Author: phryneas

src/testing/matchers/index.d.ts

@@ -2,7 +2,7 @@ import type {
   ApolloClient,
   DocumentNode,
   OperationVariables,
-} from '../../core';
+} from '../../core/index.js';
 
 interface ApolloCustomMatchers<R = void> {
   /**

src/testing/matchers/index.ts

@@ -1,6 +1,6 @@
 import { expect } from '@jest/globals';
-import { toMatchDocument } from './toMatchDocument';
-import { toHaveSuspenseCacheEntryUsing } from './toHaveSuspenseCacheEntryUsing';
+import { toMatchDocument } from './toMatchDocument.js';
+import { toHaveSuspenseCacheEntryUsing } from './toHaveSuspenseCacheEntryUsing.js';
 
 expect.extend({
   toHaveSuspenseCacheEntryUsing,

src/testing/matchers/toHaveSuspenseCacheEntryUsing.ts

@@ -1,8 +1,8 @@
 import type { MatcherFunction } from 'expect';
 import type { DocumentNode } from 'graphql';
-import type { ApolloClient, OperationVariables } from '../../core';
-import { SuspenseCache } from '../../react';
-import { canonicalStringify } from '../../cache';
+import type { ApolloClient, OperationVariables } from '../../core/index.js';
+import { SuspenseCache } from '../../react/index.js';
+import { canonicalStringify } from '../../cache/index.js';
 
 export const toHaveSuspenseCacheEntryUsing: MatcherFunction<
   [

src/testing/matchers/toMatchDocument.ts

@@ -1,5 +1,5 @@
-import { checkDocument, print } from '../../utilities';
-import type { DocumentNode } from '../../core';
+import { checkDocument, print } from '../../utilities/index.js';
+import type { DocumentNode } from '../../core/index.js';
 import type { MatcherFunction } from 'expect';
 
 export const toMatchDocument: MatcherFunction<[document: DocumentNode]> =