Prevent disposing stubbed modules

Author: CompuIves

packages/app/src/sandbox/eval/entities/module.js

@@ -5,4 +5,6 @@ export type Module = {
   code: string,
   requires?: Array<string>,
   downloaded?: boolean,
+  /** Whether the module was created as stub for the "browsers" package field */
+  stubbed?: boolean,
 };

packages/app/src/sandbox/eval/npm/fetch-npm-module.js

@@ -334,6 +334,7 @@ export default async function fetchModule(
         : pathUtils.join(currentPath, path),
       code: 'module.exports = {};',
       requires: [],
+      stubbed: true,
     };
   }
 

packages/app/src/sandbox/eval/transpiled-module.js

@@ -17,7 +17,6 @@ import type { WarningStructure } from './transpilers/utils/worker-warning-handle
 
 import resolveDependency from './loaders/dependency-resolver';
 import evaluate from './loaders/eval';
-import isESModule from './utils/is-es-module';
 
 import type { default as Manager } from './manager';
 import HMR from './hmr';
@@ -977,7 +976,10 @@ export default class TranspiledModule {
       this.initiators.size === 0 &&
       this.transpilationInitiators.size === 0 &&
       !this.isEntry &&
-      !manager.isFirstLoad
+      !manager.isFirstLoad &&
+      // Don't delete stubbed modules, they are here for a reason, most probably
+      // because they are aliased with a browser field
+      !this.module.stubbed
     ) {
       // Remove the module from the transpiler if it's not used anymore
       debug(`Removing '${this.getId()}' from manager.`);