[WIP] feat: per module inlineDynamicImport

src/Module.ts

@@ -194,6 +194,7 @@ export default class Module {
 	importDescriptions: { [name: string]: ImportDescription } = Object.create(null);
 	importMetas: MetaProperty[] = [];
 	imports = new Set<Variable>();
+	inlineDynamicImport = false;
 	isEntryPoint: boolean;
 	isExecuted = false;
 	isUserDefinedEntryPoint = false;
@@ -221,12 +222,19 @@ export default class Module {
 	private transformDependencies: string[] = [];
 	private transitiveReexports: string[] | null = null;
 
-	constructor(graph: Graph, id: string, moduleSideEffects: boolean, isEntry: boolean) {
+	constructor(
+		graph: Graph,
+		id: string,
+		moduleSideEffects: boolean,
+		inlineDynamicImport: boolean,
+		isEntry: boolean
+	) {
 		this.id = id;
 		this.graph = graph;
 		this.excludeFromSourcemap = /\0/.test(id);
 		this.context = graph.getModuleContext(id);
 		this.moduleSideEffects = moduleSideEffects;
+		this.inlineDynamicImport = inlineDynamicImport;
 		this.isEntryPoint = isEntry;
 	}
 
@@ -534,6 +542,7 @@ export default class Module {
 		originalSourcemap,
 		resolvedIds,
 		sourcemapChain,
+		inlineDynamicImport,
 		transformDependencies,
 		transformFiles
 	}: TransformModuleJSON & {
@@ -551,6 +560,9 @@ export default class Module {
 		if (typeof moduleSideEffects === 'boolean') {
 			this.moduleSideEffects = moduleSideEffects;
 		}
+		if (typeof inlineDynamicImport === 'boolean') {
+			this.inlineDynamicImport = inlineDynamicImport;
+		}
 
 		timeStart('generate ast', 3);
 
@@ -629,6 +641,7 @@ export default class Module {
 			customTransformCache: this.customTransformCache,
 			dependencies: this.dependencies.map(module => module.id),
 			id: this.id,
+			inlineDynamicImport: this.inlineDynamicImport,
 			moduleSideEffects: this.moduleSideEffects,
 			originalCode: this.originalCode,
 			originalSourcemap: this.originalSourcemap,

src/ModuleLoader.ts

@@ -272,6 +272,7 @@ export class ModuleLoader {
 		id: string,
 		importer: string,
 		moduleSideEffects: boolean,
+		inlineDynamicImport: boolean,
 		isEntry: boolean
 	): Promise<Module> {
 		const existingModule = this.modulesById.get(id);
@@ -280,7 +281,7 @@ export class ModuleLoader {
 			return Promise.resolve(existingModule);
 		}
 
-		const module: Module = new Module(this.graph, id, moduleSideEffects, isEntry);
+		const module = new Module(this.graph, id, moduleSideEffects, inlineDynamicImport, isEntry);
 		this.modulesById.set(id, module);
 		this.graph.watchFiles[id] = true;
 		const manualChunkAlias = this.getManualChunk(id);
@@ -321,6 +322,9 @@ export class ModuleLoader {
 				if (typeof sourceDescription.moduleSideEffects === 'boolean') {
 					module.moduleSideEffects = sourceDescription.moduleSideEffects;
 				}
+				if (typeof sourceDescription.inlineDynamicImport === 'boolean') {
+					module.inlineDynamicImport = sourceDescription.inlineDynamicImport;
+				}
 				return transform(this.graph, sourceDescription, module);
 			})
 			.then((source: TransformModuleJSON | ModuleJSON) => {
@@ -370,7 +374,13 @@ export class ModuleLoader {
 			}
 			return Promise.resolve(externalModule);
 		} else {
-			return this.fetchModule(resolvedId.id, importer, resolvedId.moduleSideEffects, false);
+			return this.fetchModule(
+				resolvedId.id,
+				importer,
+				resolvedId.moduleSideEffects,
+				resolvedId.inlineDynamicImport,
+				false
+			);
 		}
 	}
 
@@ -387,6 +397,7 @@ export class ModuleLoader {
 			return {
 				external: true,
 				id: source,
+				inlineDynamicImport: true,
 				moduleSideEffects: this.hasModuleSideEffects(source, true)
 			};
 		}
@@ -407,7 +418,7 @@ export class ModuleLoader {
 					: resolveIdResult;
 
 			if (typeof id === 'string') {
-				return this.fetchModule(id, undefined as any, true, isEntry);
+				return this.fetchModule(id, undefined as any, true, false, isEntry);
 			}
 			return error(errUnresolvedEntry(unresolvedId));
 		});
@@ -420,6 +431,7 @@ export class ModuleLoader {
 		let id = '';
 		let external = false;
 		let moduleSideEffects = null;
+		let inlineDynamicImport = false;
 		if (resolveIdResult) {
 			if (typeof resolveIdResult === 'object') {
 				id = resolveIdResult.id;
@@ -429,6 +441,9 @@ export class ModuleLoader {
 				if (typeof resolveIdResult.moduleSideEffects === 'boolean') {
 					moduleSideEffects = resolveIdResult.moduleSideEffects;
 				}
+				if (typeof resolveIdResult.inlineDynamicImport === 'boolean') {
+					inlineDynamicImport = resolveIdResult.inlineDynamicImport;
+				}
 			} else {
 				if (this.isExternal(resolveIdResult, importer, true)) {
 					external = true;
@@ -445,6 +460,7 @@ export class ModuleLoader {
 		return {
 			external,
 			id,
+			inlineDynamicImport,
 			moduleSideEffects:
 				typeof moduleSideEffects === 'boolean'
 					? moduleSideEffects

src/rollup/types.d.ts

@@ -91,6 +91,7 @@ export type SourceMapInput = ExistingRawSourceMap | string | null | { mappings:
 export interface SourceDescription {
 	ast?: ESTree.Program;
 	code: string;
+	inlineDynamicImport?: boolean | null;
 	map?: SourceMapInput;
 	moduleSideEffects?: boolean | null;
 }
@@ -104,6 +105,7 @@ export interface TransformModuleJSON {
 	code: string;
 	// note if plugins use new this.cache to opt-out auto transform cache
 	customTransformCache: boolean;
+	inlineDynamicImport: boolean | null;
 	moduleSideEffects: boolean | null;
 	originalCode: string;
 	originalSourcemap: ExistingDecodedSourceMap | null;
@@ -198,6 +200,7 @@ export interface PluginContextMeta {
 export interface ResolvedId {
 	external: boolean;
 	id: string;
+	inlineDynamicImport: boolean;
 	moduleSideEffects: boolean;
 }
 
@@ -208,6 +211,7 @@ export interface ResolvedIdMap {
 interface PartialResolvedId {
 	external?: boolean;
 	id: string;
+	inlineDynamicImport?: boolean | null;
 	moduleSideEffects?: boolean | null;
 }
 

src/utils/chunkColouring.ts

@@ -19,6 +19,11 @@ export function assignChunkColouringHashes(
 			Uint8ArrayXor(module.entryPointsHash, currentEntryHash);
 		}
 
+		for (const { resolution } of module.dynamicImports) {
+			if (resolution instanceof Module && resolution.inlineDynamicImport) {
+				module.dependencies.push(resolution);
+			}
+		}
 		for (const dependency of module.dependencies) {
 			if (
 				dependency instanceof ExternalModule ||
@@ -35,6 +40,7 @@ export function assignChunkColouringHashes(
 		for (const { resolution } of module.dynamicImports) {
 			if (
 				resolution instanceof Module &&
+				!resolution.inlineDynamicImport &&
 				resolution.dynamicallyImportedBy.length > 0 &&
 				!resolution.manualChunkAlias
 			) {

src/utils/transform.ts

@@ -35,6 +35,7 @@ export default function transform(
 	const emittedFiles: EmittedFile[] = [];
 	let customTransformCache = false;
 	let moduleSideEffects: boolean | null = null;
+	let inlineDynamicImport: boolean | null = null;
 	let trackedPluginCache: { cache: PluginCache; used: boolean };
 	let curPlugin: Plugin;
 	const curSource: string = source.code;
@@ -82,6 +83,9 @@ export default function transform(
 			if (typeof result.moduleSideEffects === 'boolean') {
 				moduleSideEffects = result.moduleSideEffects;
 			}
+			if (typeof result.inlineDynamicImport === 'boolean') {
+				inlineDynamicImport = result.inlineDynamicImport;
+			}
 		} else {
 			return code;
 		}
@@ -189,6 +193,7 @@ export default function transform(
 				ast: ast as any,
 				code,
 				customTransformCache,
+				inlineDynamicImport,
 				moduleSideEffects,
 				originalCode,
 				originalSourcemap,

test/chunking-form/samples/inline-dynamic-import/inline-conditionally/_config.js

@@ -0,0 +1,16 @@
+module.exports = {
+	description: 'inlines dynamic imports with side-effects that are only executed conditionally',
+	options: {
+		input: 'main.js',
+		plugins: {
+			transform(code, id) {
+				if (id.endsWith('inlined.js')) {
+					return {
+						code,
+						inlineDynamicImport: true
+					};
+				}
+			}
+		}
+	}
+};

test/chunking-form/samples/inline-dynamic-import/inline-conditionally/_expected/amd/main.js

@@ -0,0 +1,17 @@
+define(function () { 'use strict';
+
+	if (globalThis.unknown) {
+		Promise.resolve().then(function () { return inlined; }).then(console.log);
+	}
+
+	console.log('main1');
+
+	console.log('inlined');
+	const value = 'inlined';
+
+	var inlined = /*#__PURE__*/Object.freeze({
+		__proto__: null,
+		value: value
+	});
+
+});

test/chunking-form/samples/inline-dynamic-import/inline-conditionally/_expected/cjs/main.js

@@ -0,0 +1,15 @@
+'use strict';
+
+if (globalThis.unknown) {
+	Promise.resolve().then(function () { return inlined; }).then(console.log);
+}
+
+console.log('main1');
+
+console.log('inlined');
+const value = 'inlined';
+
+var inlined = /*#__PURE__*/Object.freeze({
+	__proto__: null,
+	value: value
+});

test/chunking-form/samples/inline-dynamic-import/inline-conditionally/_expected/es/main.js

@@ -0,0 +1,13 @@
+if (globalThis.unknown) {
+	Promise.resolve().then(function () { return inlined; }).then(console.log);
+}
+
+console.log('main1');
+
+console.log('inlined');
+const value = 'inlined';
+
+var inlined = /*#__PURE__*/Object.freeze({
+	__proto__: null,
+	value: value
+});

test/chunking-form/samples/inline-dynamic-import/inline-conditionally/_expected/system/main.js

@@ -0,0 +1,22 @@
+System.register([], function () {
+	'use strict';
+	return {
+		execute: function () {
+
+			if (globalThis.unknown) {
+				Promise.resolve().then(function () { return inlined; }).then(console.log);
+			}
+
+			console.log('main1');
+
+			console.log('inlined');
+			const value = 'inlined';
+
+			var inlined = /*#__PURE__*/Object.freeze({
+				__proto__: null,
+				value: value
+			});
+
+		}
+	};
+});

test/chunking-form/samples/inline-dynamic-import/inline-conditionally/inlined.js

@@ -0,0 +1,2 @@
+console.log('inlined');
+export const value = 'inlined';

test/chunking-form/samples/inline-dynamic-import/inline-conditionally/main.js

@@ -0,0 +1,5 @@
+if (globalThis.unknown) {
+	import('./inlined.js').then(console.log);
+}
+
+console.log('main1');

test/chunking-form/samples/inline-dynamic-import/inline-in-various-hooks/_config.js

@@ -0,0 +1,36 @@
+const fs = require('fs');
+const path = require('path');
+
+module.exports = {
+	description: 'inlines dynamic imports marked for inlining',
+	options: {
+		input: 'main.js',
+		plugins: {
+			resolveId(id, importer) {
+				if (id.endsWith('dep-inlined-via-resolveId.js')) {
+					return this.resolve(id, importer, { skipSelf: true }).then(resolution =>
+						Object.assign({}, resolution, { inlineDynamicImport: true })
+					);
+				}
+			},
+			load(id) {
+				if (id.endsWith('dep-inlined-via-load.js')) {
+					return {
+						code: fs.readFileSync(path.resolve(__dirname, 'dep-inlined-via-load.js'), {
+							encoding: 'utf8'
+						}),
+						inlineDynamicImport: true
+					};
+				}
+			},
+			transform(code, id) {
+				if (id.endsWith('dep-inlined-via-transform.js')) {
+					return {
+						code,
+						inlineDynamicImport: true
+					};
+				}
+			}
+		}
+	}
+};

test/chunking-form/samples/inline-dynamic-import/inline-in-various-hooks/_expected/amd/generated-dep-not-inlined.js

@@ -0,0 +1,8 @@
+define(['exports'], function (exports) { 'use strict';
+
+	console.log('not inlined');
+	const value = 'not inlined';
+
+	exports.value = value;
+
+});

test/chunking-form/samples/inline-dynamic-import/inline-in-various-hooks/_expected/amd/main.js

@@ -0,0 +1,34 @@
+define(['require'], function (require) { 'use strict';
+
+	Promise.resolve().then(function () { return depInlinedViaResolveId; }).then(console.log);
+	Promise.resolve().then(function () { return depInlinedViaLoad; }).then(console.log);
+	Promise.resolve().then(function () { return depInlinedViaTransform; }).then(console.log);
+	new Promise(function (resolve, reject) { require(['./generated-dep-not-inlined'], resolve, reject) }).then(console.log);
+
+	console.log('main');
+
+	console.log('resolveId');
+	const value = 'resolveId';
+
+	var depInlinedViaResolveId = /*#__PURE__*/Object.freeze({
+		__proto__: null,
+		value: value
+	});
+
+	console.log('load');
+	const value$1 = 'load';
+
+	var depInlinedViaLoad = /*#__PURE__*/Object.freeze({
+		__proto__: null,
+		value: value$1
+	});
+
+	console.log('transform');
+	const value$2 = 'transform';
+
+	var depInlinedViaTransform = /*#__PURE__*/Object.freeze({
+		__proto__: null,
+		value: value$2
+	});
+
+});