Inline dynamic imports that are also imported statically and only use…

…d in a single chunk (#2295)

src/Chunk.ts

@@ -214,6 +214,11 @@ export default class Chunk {
 			const declaration = module.imports[importName];
 			this.traceImport(declaration.name, declaration.module);
 		}
+		for (const { resolution } of module.dynamicImportResolutions) {
+			this.hasDynamicImport = true;
+			if (resolution instanceof Module && resolution.chunk === this)
+				resolution.getOrCreateNamespace().include();
+		}
 	}
 
 	// Note preserveModules implementation is not a comprehensive technique
@@ -397,7 +402,6 @@ export default class Chunk {
 			for (let i = 0; i < module.dynamicImportResolutions.length; i++) {
 				const node = module.dynamicImports[i];
 				const resolution = module.dynamicImportResolutions[i].resolution;
-				this.hasDynamicImport = true;
 
 				if (!resolution) continue;
 
@@ -406,7 +410,6 @@ export default class Chunk {
 					// ensuring that we create a namespace import of it as well
 					if (resolution.chunk === this) {
 						const namespace = resolution.getOrCreateNamespace();
-						namespace.include();
 						node.setResolution(false, namespace.getName());
 						// for the module in another chunk, import that other chunk directly
 					} else {
@@ -772,8 +775,6 @@ export default class Chunk {
 		const n = options.compact ? '' : '\n';
 		const _ = options.compact ? '' : ' ';
 
-		this.prepareDynamicImports();
-
 		const renderOptions: RenderOptions = {
 			compact: options.compact,
 			freeze: options.freeze !== false,
@@ -807,6 +808,7 @@ export default class Chunk {
 		}
 
 		this.setIdentifierRenderResolutions(options);
+		this.prepareDynamicImports();
 
 		let hoistedSource = '';
 

src/Graph.ts

@@ -28,7 +28,12 @@ import {
 import { Asset, createAssetPluginHooks, finaliseAsset } from './utils/assetHooks';
 import { load, makeOnwarn, resolveId } from './utils/defaults';
 import ensureArray from './utils/ensureArray';
-import { randomUint8Array, Uint8ArrayToHexString, Uint8ArrayXor } from './utils/entryHashing';
+import {
+	randomUint8Array,
+	Uint8ArrayEqual,
+	Uint8ArrayToHexString,
+	Uint8ArrayXor
+} from './utils/entryHashing';
 import error from './utils/error';
 import first from './utils/first';
 import { isRelative, relative, resolve } from './utils/path';
@@ -537,7 +542,15 @@ export default class Graph {
 			}
 
 			for (const dynamicModule of module.dynamicImportResolutions) {
-				if (dynamicModule.resolution instanceof Module) {
+				if (!(dynamicModule.resolution instanceof Module)) continue;
+				// If the parent module of a dynamic import is to a child module whose graph
+				// colouring is the same as the parent module, then that dynamic import does
+				// not need to be treated as a new entry point as it is in the static graph
+				if (
+					!graphColouring ||
+					(!dynamicModule.resolution.chunkAlias &&
+						!Uint8ArrayEqual(dynamicModule.resolution.entryPointsHash, curEntry.entryPointsHash))
+				) {
 					if (dynamicImports.indexOf(dynamicModule.resolution) === -1) {
 						dynamicImports.push(dynamicModule.resolution);
 						dynamicImportAliases.push(dynamicModule.alias);

src/utils/entryHashing.ts

@@ -29,6 +29,13 @@ export function randomUint8Array(len: number) {
 	return buffer;
 }
 
+export function Uint8ArrayEqual(bufferA: Uint8Array, bufferB: Uint8Array) {
+	for (let i = 0; i < bufferA.length; i++) {
+		if (bufferA[i] !== bufferB[i]) return false;
+	}
+	return true;
+}
+
 export function randomHexString(len: number) {
 	return Uint8ArrayToHexString(randomUint8Array(Math.floor(len / 2)));
 }

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

@@ -0,0 +1,6 @@
+module.exports = {
+	description: 'Dynamic import inlining for static colouring',
+	options: {
+		input: ['main.js']
+	}
+};

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

@@ -0,0 +1,13 @@
+define(['require'], function (require) { 'use strict';
+
+	var foo = "FOO";
+
+	var foo$1 = /*#__PURE__*/Object.freeze({
+		default: foo
+	});
+
+	var main = Promise.resolve().then(function () { return foo$1; });
+
+	return main;
+
+});

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

@@ -0,0 +1,11 @@
+'use strict';
+
+var foo = "FOO";
+
+var foo$1 = /*#__PURE__*/Object.freeze({
+	default: foo
+});
+
+var main = Promise.resolve().then(function () { return foo$1; });
+
+module.exports = main;

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

@@ -0,0 +1,9 @@
+var foo = "FOO";
+
+var foo$1 = /*#__PURE__*/Object.freeze({
+	default: foo
+});
+
+var main = Promise.resolve().then(function () { return foo$1; });
+
+export default main;

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

@@ -0,0 +1,16 @@
+System.register([], function (exports, module) {
+	'use strict';
+	return {
+		execute: function () {
+
+			var foo = "FOO";
+
+			var foo$1 = /*#__PURE__*/Object.freeze({
+				default: foo
+			});
+
+			var main = exports('default', Promise.resolve().then(function () { return foo$1; }));
+
+		}
+	};
+});

test/chunking-form/samples/dynamic-import-inline-colouring/foo.js

@@ -0,0 +1 @@
+export default "FOO";

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

@@ -0,0 +1,3 @@
+import foo from "./foo.js";
+
+export default import("./foo.js");

test/form/samples/dynamic-import-inlining/_expected.js

@@ -5,6 +5,6 @@ var foo$1 = /*#__PURE__*/Object.freeze({
 });
 
 const bar = 2;
-Promise.resolve().then(function () { return foo; });
+Promise.resolve().then(function () { return foo$1; });
 
 export { bar };