Also pass resolved ids to external if they use the object form

src/ModuleLoader.ts

@@ -423,7 +423,7 @@ export class ModuleLoader {
 		if (resolveIdResult) {
 			if (typeof resolveIdResult === 'object') {
 				id = resolveIdResult.id;
-				if (resolveIdResult.external) {
+				if (resolveIdResult.external || this.options.external(resolveIdResult.id, importer, true)) {
 					external = true;
 				}
 				if (resolveIdResult.moduleSideEffects != null) {

test/function/samples/external-resolved/_config.js

@@ -0,0 +1,51 @@
+const assert = require('assert');
+
+const testedIds = [];
+
+module.exports = {
+	description: 'passes both unresolved and resolved ids to the external option',
+	context: {
+		require() {
+			return true;
+		}
+	},
+	exports(exports) {
+		assert.deepStrictEqual(exports, {
+			resolvedExternal: true,
+			resolvedObject: true,
+			resolvedObjectExternal: true,
+			resolvedString: true
+		});
+		assert.deepStrictEqual(testedIds, [
+			'resolve-string',
+			'resolve-external',
+			'resolve-object',
+			'resolve-object-external',
+			'resolved-string',
+			'resolved-object'
+		]);
+	},
+	options: {
+		external(id) {
+			testedIds.push(id);
+			return id.startsWith('resolved');
+		},
+		plugins: {
+			name: 'test-plugin',
+			resolveId(source) {
+				switch (source) {
+					case 'resolve-string':
+						return 'resolved-string';
+					case 'resolve-external':
+						return false;
+					case 'resolve-object':
+						return { id: 'resolved-object', external: false };
+					case 'resolve-object-external':
+						return { id: 'resolved-object-external', external: true };
+					default:
+						return null;
+				}
+			}
+		}
+	}
+};

test/function/samples/external-resolved/main.js

@@ -0,0 +1,4 @@
+export {default as resolvedString} from 'resolve-string';
+export {default as resolvedExternal} from 'resolve-external';
+export {default as resolvedObject} from 'resolve-object';
+export {default as resolvedObjectExternal} from 'resolve-object-external';