Remove default acorn options + other fixes (#4786)

* Remove default acorn options

* Make tryParse private

* Add type

* Remove type assertion

* Remove non-null assertion operator

* Use more nullish coalescing

* Remove unused eslint parser options

Co-authored-by: Lukas Taegert-Atkinson <lukastaegert@users.noreply.github.com>

.eslintrc.js

@@ -50,10 +50,6 @@ module.exports = {
 		}
 	],
 	parser: '@typescript-eslint/parser',
-	parserOptions: {
-		ecmaVersion: 2018,
-		sourceType: 'module'
-	},
 	plugins: ['@typescript-eslint'],
 	rules: {
 		'@typescript-eslint/consistent-type-assertions': [

src/Bundle.ts

@@ -142,7 +142,6 @@ export default class Bundle {
 				if ('code' in file) {
 					try {
 						this.graph.contextParse(file.code, {
-							allowHashBang: true,
 							ecmaVersion: 'latest'
 						});
 					} catch (error_: any) {

src/Module.ts

@@ -771,12 +771,12 @@ export default class Module {
 		this.transformDependencies = transformDependencies;
 		this.customTransformCache = customTransformCache;
 		this.updateOptions(moduleOptions);
-		const moduleAst = ast || this.tryParse();
+		const moduleAst = ast ?? this.tryParse();
 
 		timeEnd('generate ast', 3);
 		timeStart('analyze ast', 3);
 
-		this.resolvedIds = resolvedIds || Object.create(null);
+		this.resolvedIds = resolvedIds ?? Object.create(null);
 
 		// By default, `id` is the file name. Custom resolvers and loaders
 		// can change that, but it makes sense to use it for the source file name
@@ -910,14 +910,6 @@ export default class Module {
 		return null;
 	}
 
-	tryParse(): acorn.Node {
-		try {
-			return this.graph.contextParse(this.info.code!);
-		} catch (error_: any) {
-			return this.error(errorParseError(error_, this.id), error_.pos);
-		}
-	}
-
 	updateOptions({
 		meta,
 		moduleSideEffects,
@@ -1259,6 +1251,14 @@ export default class Module {
 		this.options.onwarn(errorShimmedExport(this.id, name));
 		this.exports.set(name, MISSING_EXPORT_SHIM_DESCRIPTION);
 	}
+
+	private tryParse(): acorn.Node {
+		try {
+			return this.graph.contextParse(this.info.code!);
+		} catch (error_: any) {
+			return this.error(errorParseError(error_, this.id), error_.pos);
+		}
+	}
 }
 
 // if there is a cyclic import in the reexport chain, we should not

src/utils/PluginDriver.ts

@@ -306,7 +306,7 @@ export class PluginDriver {
 		replaceContext?: ReplaceContext | null
 	): Promise<unknown> {
 		// We always filter for plugins that support the hook before running it
-		const hook = plugin[hookName]!;
+		const hook = plugin[hookName];
 		const handler = typeof hook === 'object' ? hook.handler : hook;
 
 		let context = this.pluginContexts.get(plugin)!;

src/utils/options/normalizeInputOptions.ts

@@ -96,9 +96,7 @@ const getOnwarn = (config: InputOptions): NormalizedInputOptions['onwarn'] => {
 };
 
 const getAcorn = (config: InputOptions): acorn.Options => ({
-	allowAwaitOutsideFunction: true,
 	ecmaVersion: 'latest',
-	preserveParens: false,
 	sourceType: 'module',
 	...config.acorn
 });
@@ -208,19 +206,18 @@ const getModuleContext = (
 	config: InputOptions,
 	context: string
 ): NormalizedInputOptions['moduleContext'] => {
-	const configModuleContext = config.moduleContext as
-		| ((id: string) => string | null | undefined)
-		| { [id: string]: string }
-		| undefined;
+	const configModuleContext = config.moduleContext;
 	if (typeof configModuleContext === 'function') {
 		return id => configModuleContext(id) ?? context;
 	}
 	if (configModuleContext) {
-		const contextByModuleId = Object.create(null);
+		const contextByModuleId: {
+			[key: string]: string;
+		} = Object.create(null);
 		for (const [key, moduleContext] of Object.entries(configModuleContext)) {
 			contextByModuleId[resolve(key)] = moduleContext;
 		}
-		return id => contextByModuleId[id] || context;
+		return id => contextByModuleId[id] ?? context;
 	}
 	return () => context;
 };

test/function/samples/options-hook/_config.js

@@ -10,9 +10,7 @@ module.exports = {
 			buildStart(options) {
 				assert.deepStrictEqual(JSON.parse(JSON.stringify(options)), {
 					acorn: {
-						allowAwaitOutsideFunction: true,
 						ecmaVersion: 'latest',
-						preserveParens: false,
 						sourceType: 'module'
 					},
 					acornInjectPlugins: [null],