Do not require input to be set if a dynamic entry is emitted

src/Graph.ts

@@ -108,10 +108,6 @@ export default class Graph {
 
 		this.cacheExpiry = options.experimentalCacheExpiry;
 
-		if (!options.input) {
-			throw new Error('You must supply options.input to rollup');
-		}
-
 		this.treeshake = options.treeshake !== false;
 		if (this.treeshake) {
 			this.treeshakingOptions = options.treeshake
@@ -214,6 +210,9 @@ export default class Graph {
 			this.moduleLoader.addEntryModules(normalizeEntryModules(entryModules), true),
 			manualChunks && this.moduleLoader.addManualChunks(manualChunks)
 		]).then(([{ entryModules, manualChunkModulesByAlias }]) => {
+			if (entryModules.length === 0) {
+				throw new Error('You must supply options.input to rollup');
+			}
 			for (const entryModule of entryModules) {
 				if (entryModule.chunkAlias === null) {
 					entryModule.chunkAlias = getAliasName(entryModule.id);

src/finalisers/amd.ts

@@ -6,7 +6,7 @@ import getExportBlock from './shared/getExportBlock';
 import getInteropBlock from './shared/getInteropBlock';
 import warnOnBuiltins from './shared/warnOnBuiltins';
 
-// TODO Lukas consider improved AMD relative imports:
+// TODO consider using improved AMD relative imports:
 // https://requirejs.org/docs/api.html#modulenotes-urls
 
 // AMD resolution will only respect the AMD baseUrl if the .js extension is omitted.

src/rollup/index.ts

@@ -67,7 +67,7 @@ function applyOptionHook(inputOptions: InputOptions, plugin: Plugin) {
 	return inputOptions;
 }
 
-function getInputOptions(rawInputOptions: GenericConfigObject): any {
+function getInputOptions(rawInputOptions: GenericConfigObject): InputOptions {
 	if (!rawInputOptions) {
 		throw new Error('You must supply an options object to rollup');
 	}

src/rollup/types.d.ts

@@ -214,7 +214,6 @@ export type ResolveAssetUrlHook = (
 	}
 ) => string | void;
 
-// TODO Lukas do not require an input to be present if entries are created dynamically
 export type ResolveFileUrlHook = (
 	this: PluginContext,
 	options: {
@@ -326,7 +325,7 @@ export interface InputOptions {
 	experimentalTopLevelAwait?: boolean;
 	external?: ExternalOption;
 	inlineDynamicImports?: boolean;
-	input: InputOption;
+	input?: InputOption;
 	manualChunks?: { [chunkAlias: string]: string[] };
 	moduleContext?: ((id: string) => string) | { [id: string]: string };
 	onwarn?: WarningHandler;

src/utils/mergeOptions.ts

@@ -88,7 +88,7 @@ export default function mergeOptions({
 	config: GenericConfigObject;
 	defaultOnWarnHandler?: WarningHandler;
 }): {
-	inputOptions: any;
+	inputOptions: InputOptions;
 	optionError: string | null;
 	outputOptions: any;
 } {
@@ -204,7 +204,7 @@ function getInputOptions(
 		experimentalTopLevelAwait: getOption('experimentalTopLevelAwait'),
 		external: getExternal(config, command),
 		inlineDynamicImports: getOption('inlineDynamicImports', false),
-		input: getOption('input'),
+		input: getOption('input', []),
 		manualChunks: getOption('manualChunks'),
 		moduleContext: config.moduleContext,
 		onwarn: getOnWarn(config, command, defaultOnWarnHandler),

src/watch/index.ts

@@ -9,7 +9,8 @@ import {
 	RollupBuild,
 	RollupCache,
 	RollupWatcher,
-	RollupWatchOptions
+	RollupWatchOptions,
+	WatcherOptions
 } from '../rollup/types';
 import mergeOptions from '../utils/mergeOptions';
 import chokidar from './chokidar';
@@ -28,7 +29,7 @@ export class Watcher {
 	private tasks: Task[];
 
 	constructor(configs: RollupWatchOptions[]) {
-		this.emitter = new class extends EventEmitter implements RollupWatcher {
+		this.emitter = new (class extends EventEmitter implements RollupWatcher {
 			close: () => void;
 			constructor(close: () => void) {
 				super();
@@ -37,7 +38,7 @@ export class Watcher {
 				// showing the `MaxListenersExceededWarning` to the user.
 				this.setMaxListeners(Infinity);
 			}
-		}(this.close.bind(this));
+		})(this.close.bind(this));
 		this.tasks = (Array.isArray(configs) ? configs : configs ? [configs] : []).map(
 			config => new Task(this, config)
 		);
@@ -144,8 +145,9 @@ export class Task {
 			if (output.file || output.dir) return path.resolve(output.file || output.dir);
 		});
 
-		const watchOptions = inputOptions.watch || {};
-		if ('useChokidar' in watchOptions) watchOptions.chokidar = watchOptions.useChokidar;
+		const watchOptions: WatcherOptions = inputOptions.watch || {};
+		if ('useChokidar' in watchOptions)
+			(watchOptions as any).chokidar = (watchOptions as any).useChokidar;
 		let chokidarOptions = 'chokidar' in watchOptions ? watchOptions.chokidar : !!chokidar;
 		if (chokidarOptions) {
 			chokidarOptions = {
@@ -161,7 +163,7 @@ export class Task {
 			);
 		}
 
-		this.chokidarOptions = chokidarOptions;
+		this.chokidarOptions = chokidarOptions as WatchOptions;
 		this.chokidarOptionsHash = JSON.stringify(chokidarOptions);
 
 		this.filter = createFilter(watchOptions.include, watchOptions.exclude);

test/function/samples/emit-chunk/no-input/_config.js

@@ -0,0 +1,12 @@
+module.exports = {
+	description: 'It is not necessary to provide an input if a dynamic entry is emitted',
+	options: {
+		input: undefined,
+		plugins: {
+			name: 'test-plugin',
+			buildStart() {
+				this.emitChunk('chunk.js');
+			}
+		}
+	}
+};

test/function/samples/emit-chunk/no-input/chunk.js

@@ -0,0 +1 @@
+assert.equal(42, 42);