Merge pull request #1358 from sveltejs/gh-1038

Add support for shorthand imports of components

src/generators/Generator.ts

@@ -17,7 +17,7 @@ import clone from '../utils/clone';
 import Stylesheet from '../css/Stylesheet';
 import { test } from '../config';
 import nodes from './nodes/index';
-import { Node, GenerateOptions, Parsed, CompileOptions, CustomElementOptions } from '../interfaces';
+import { Node, GenerateOptions, ShorthandImport, Parsed, CompileOptions, CustomElementOptions } from '../interfaces';
 
 interface Computation {
 	key: string;
@@ -90,6 +90,7 @@ export default class Generator {
 
 	defaultExport: Node[];
 	imports: Node[];
+	shorthandImports: ShorthandImport[];
 	helpers: Set<string>;
 	components: Set<string>;
 	events: Set<string>;
@@ -139,6 +140,7 @@ export default class Generator {
 		this.options = options;
 
 		this.imports = [];
+		this.shorthandImports = [];
 		this.helpers = new Set();
 		this.components = new Set();
 		this.events = new Set();
@@ -315,7 +317,7 @@ export default class Generator {
 	generate(result: string, options: CompileOptions, { banner = '', sharedPath, helpers, name, format }: GenerateOptions ) {
 		const pattern = /\[✂(\d+)-(\d+)$/;
 
-		const module = wrapModule(result, format, name, options, banner, sharedPath, helpers, this.imports, this.source);
+		const module = wrapModule(result, format, name, options, banner, sharedPath, helpers, this.imports, this.shorthandImports, this.source);
 
 		const parts = module.split('✂]');
 		const finalChunk = parts.pop();
@@ -517,7 +519,7 @@ export default class Generator {
 					`);
 				};
 
-				const addDeclaration = (key: string, node: Node, disambiguator?: string, conflicts?: Record<string, boolean>) => {
+				const addDeclaration = (key: string, node: Node, allowShorthandImport?: boolean, disambiguator?: string, conflicts?: Record<string, boolean>) => {
 					const qualified = disambiguator ? `${disambiguator}-${key}` : key;
 
 					if (node.type === 'Identifier' && node.name === key) {
@@ -531,6 +533,11 @@ export default class Generator {
 					let name = this.getUniqueName(deconflicted);
 					this.templateVars.set(qualified, name);
 
+					if (allowShorthandImport && node.type === 'Literal' && typeof node.value === 'string') {
+						this.shorthandImports.push({ name, source: node.value });
+						return;
+					}
+
 					// deindent
 					const indentationLevel = getIndentationLevel(source, node.start);
 					if (indentationLevel) {
@@ -548,7 +555,7 @@ export default class Generator {
 
 				if (templateProperties.components) {
 					templateProperties.components.value.properties.forEach((property: Node) => {
-						addDeclaration(getName(property.key), property.value, 'components');
+						addDeclaration(getName(property.key), property.value, true, 'components');
 					});
 				}
 
@@ -582,7 +589,7 @@ export default class Generator {
 
 						const prop = templateProperties.computed.value.properties.find((prop: Node) => getName(prop.key) === key);
 
-						addDeclaration(key, prop.value, 'computed', {
+						addDeclaration(key, prop.value, false, 'computed', {
 							state: true,
 							changed: true
 						});
@@ -599,13 +606,13 @@ export default class Generator {
 
 				if (templateProperties.events && dom) {
 					templateProperties.events.value.properties.forEach((property: Node) => {
-						addDeclaration(getName(property.key), property.value, 'events');
+						addDeclaration(getName(property.key), property.value, false, 'events');
 					});
 				}
 
 				if (templateProperties.helpers) {
 					templateProperties.helpers.value.properties.forEach((property: Node) => {
-						addDeclaration(getName(property.key), property.value, 'helpers');
+						addDeclaration(getName(property.key), property.value, false, 'helpers');
 					});
 				}
 
@@ -660,13 +667,13 @@ export default class Generator {
 
 				if (templateProperties.transitions) {
 					templateProperties.transitions.value.properties.forEach((property: Node) => {
-						addDeclaration(getName(property.key), property.value, 'transitions');
+						addDeclaration(getName(property.key), property.value, false, 'transitions');
 					});
 				}
 
 				if (templateProperties.actions) {
 					templateProperties.actions.value.properties.forEach((property: Node) => {
-						addDeclaration(getName(property.key), property.value, 'actions');
+						addDeclaration(getName(property.key), property.value, false, 'actions');
 					});
 				}
 			}

src/generators/wrapModule.ts

@@ -1,6 +1,6 @@
 import deindent from '../utils/deindent';
 import list from '../utils/list';
-import { CompileOptions, ModuleFormat, Node } from '../interfaces';
+import { CompileOptions, ModuleFormat, Node, ShorthandImport } from '../interfaces';
 
 interface Dependency {
 	name: string;
@@ -19,9 +19,10 @@ export default function wrapModule(
 	sharedPath: string,
 	helpers: { name: string, alias: string }[],
 	imports: Node[],
+	shorthandImports: ShorthandImport[],
 	source: string
 ): string {
-	if (format === 'es') return es(code, name, options, banner, sharedPath, helpers, imports, source);
+	if (format === 'es') return es(code, name, options, banner, sharedPath, helpers, imports, shorthandImports, source);
 
 	const dependencies = imports.map((declaration, i) => {
 		const defaultImport = declaration.specifiers.find(
@@ -58,7 +59,16 @@ export default function wrapModule(
 		}
 
 		return { name, statements, source: declaration.source.value };
-	});
+	})
+	.concat(
+		shorthandImports.map(({ name, source }) => ({
+			name,
+			statements: [
+				`${name} = (${name} && ${name}.__esModule) ? ${name}["default"] : ${name};`,
+			],
+			source,
+		}))
+	);
 
 	if (format === 'amd') return amd(code, name, options, banner, dependencies);
 	if (format === 'cjs') return cjs(code, name, options, banner, sharedPath, helpers, dependencies);
@@ -77,6 +87,7 @@ function es(
 	sharedPath: string,
 	helpers: { name: string, alias: string }[],
 	imports: Node[],
+	shorthandImports: ShorthandImport[],
 	source: string
 ) {
 	const importHelpers = helpers && (
@@ -89,10 +100,15 @@ function es(
 			.join('\n')
 	);
 
+	const shorthandImportBlock = shorthandImports.length > 0 && (
+		shorthandImports.map(({ name, source }) => `import ${name} from ${JSON.stringify(source)};`).join('\n')
+	);
+
 	return deindent`
 		${banner}
 		${importHelpers}
 		${importBlock}
+		${shorthandImportBlock}
 
 		${code}
 		export default ${name};`;

src/interfaces.ts

@@ -74,6 +74,11 @@ export interface GenerateOptions {
 	helpers?: { name: string, alias: string }[];
 }
 
+export interface ShorthandImport {
+	name: string;
+	source: string;
+};
+
 export interface Visitor {
 	enter: (node: Node) => void;
 	leave?: (node: Node) => void;

test/runtime/samples/component-shorthand-import/Widget.html

@@ -0,0 +1 @@
+<p>This is the widget.</p>

test/runtime/samples/component-shorthand-import/_config.js

@@ -0,0 +1,3 @@
+export default {
+	html: `<p>This is the widget.</p>`,
+};

test/runtime/samples/component-shorthand-import/main.html

@@ -0,0 +1,5 @@
+<Widget/>
+
+<script>
+	export default { components: { Widget: './Widget.html' } };
+</script>