Merge branch 'master' into blog-anchors-2609

site/content/docs/04-compile-time.md

@@ -153,6 +153,30 @@ compiled: {
 -->
 
 
+### `svelte.parse`
+
+```js
+ast: object = svelte.parse(
+	source: string,
+	options?: {
+		filename?: string,
+		customElement?: boolean
+	}
+)
+```
+
+---
+
+The `parse` function parses a component, returning only its abstract syntax tree. Unlike compiling with the `generate: false` option, this will not perform any validation or other analysis of the component beyond parsing it.
+
+
+```js
+const svelte = require('svelte/compiler');
+
+const ast = svelte.parse(source, { filename: 'App.svelte' });
+```
+
+
 ### `svelte.preprocess`
 
 ```js
@@ -280,6 +304,38 @@ const { code } = svelte.preprocess(source, [
 ```
 
 
+### `svelte.walk`
+
+```js
+walk(ast: Node, {
+	enter(node: Node, parent: Node)?: void,
+	leave(node: Node, parent: Node)?: void
+})
+```
+
+---
+
+The `walk` function provides a way to walk to abstract syntax trees generated by the parser, using the compiler's own built-in instance of [estree-walker](https://github.com/Rich-Harris/estree-walker).
+
+The walker takes an abstract syntax tree to walk and an object with two optional methods: `enter` and `leave`. For each node, `enter` is called (if present). Then, unless `this.skip()` is called during `enter`, each of the children are traversed, and then `leave` is called on the node.
+
+
+```js
+const svelte = require('svelte/compiler');
+svelte.walk(ast, {
+	enter(node, parent) {
+		do_something(node);
+		if (should_skip_children(node)) {
+			this.skip();
+		}
+	},
+	leave(node, parent) {
+		do_something_else(node);
+	}
+});
+```
+
+
 ### `svelte.VERSION`
 
 ---

src/compile/nodes/CatchBlock.ts

@@ -1,12 +1,9 @@
-import Node from './shared/Node';
-import Block from '../render-dom/Block';
 import map_children from './shared/map_children';
 import TemplateScope from './shared/TemplateScope';
+import AbstractBlock from './shared/AbstractBlock';
 
-export default class CatchBlock extends Node {
-	block: Block;
+export default class CatchBlock extends AbstractBlock {
 	scope: TemplateScope;
-	children: Node[];
 
 	constructor(component, parent, scope, info) {
 		super(component, parent, scope, info);
@@ -15,6 +12,8 @@ export default class CatchBlock extends Node {
 		this.scope.add(parent.error, parent.expression.dependencies, this);
 		this.children = map_children(component, parent, this.scope, info.children);
 
+		if (!info.skip) {
 			this.warn_if_empty_block();
 		}
 	}
+}

src/compile/nodes/EachBlock.ts

@@ -1,9 +1,9 @@
 import Node from './shared/Node';
 import ElseBlock from './ElseBlock';
-import Block from '../render-dom/Block';
 import Expression from './shared/Expression';
 import map_children from './shared/map_children';
 import TemplateScope from './shared/TemplateScope';
+import AbstractBlock from './shared/AbstractBlock';
 import { Node as INode } from '../../interfaces';
 
 function unpack_destructuring(contexts: Array<{ name: string, tail: string }>, node: INode, tail: string) {
@@ -25,10 +25,9 @@ function unpack_destructuring(contexts: Array<{ name: string, tail: string }>, n
 	}
 }
 
-export default class EachBlock extends Node {
+export default class EachBlock extends AbstractBlock {
 	type: 'EachBlock';
 
-	block: Block;
 	expression: Expression;
 	context_node: Node;
 
@@ -41,7 +40,6 @@ export default class EachBlock extends Node {
 	has_animation: boolean;
 	has_binding = false;
 
-	children: Node[];
 	else?: ElseBlock;
 
 	constructor(component, parent, scope, info) {
@@ -85,7 +83,7 @@ export default class EachBlock extends Node {
 			}
 		}
 
-		this.warn_if_empty_block(); // TODO would be better if EachBlock, IfBlock etc extended an abstract Block class
+		this.warn_if_empty_block();
 
 		this.else = info.else
 			? new ElseBlock(component, this, this.scope, info.else)

src/compile/nodes/Element.ts

@@ -224,7 +224,21 @@ export default class Element extends Node {
 		}
 
 		if (this.name === 'figcaption') {
-			if (this.parent.name !== 'figure') {
+			let { parent } = this;
+			let is_figure_parent = false;
+
+			while (parent) {
+				if (parent.name === 'figure') {
+					is_figure_parent = true;
+					break;
+				}
+				if (parent.type === 'Element') {
+					break;
+				}
+				parent = parent.parent;
+			}
+
+			if (!is_figure_parent) {
 				this.component.warn(this, {
 					code: `a11y-structure`,
 					message: `A11y: <figcaption> must be an immediate child of <figure>`

src/compile/nodes/ElseBlock.ts

@@ -1,11 +1,8 @@
-import Node from './shared/Node';
-import Block from '../render-dom/Block';
 import map_children from './shared/map_children';
+import AbstractBlock from './shared/AbstractBlock';
 
-export default class ElseBlock extends Node {
+export default class ElseBlock extends AbstractBlock {
 	type: 'ElseBlock';
-	children: Node[];
-	block: Block;
 
 	constructor(component, parent, scope, info) {
 		super(component, parent, scope, info);

src/compile/nodes/IfBlock.ts

@@ -1,17 +1,13 @@
-import Node from './shared/Node';
 import ElseBlock from './ElseBlock';
-import Block from '../render-dom/Block';
 import Expression from './shared/Expression';
 import map_children from './shared/map_children';
+import AbstractBlock from './shared/AbstractBlock';
 
-export default class IfBlock extends Node {
+export default class IfBlock extends AbstractBlock {
 	type: 'IfBlock';
 	expression: Expression;
-	children: any[];
 	else: ElseBlock;
 
-	block: Block;
-
 	constructor(component, parent, scope, info) {
 		super(component, parent, scope, info);
 

src/compile/nodes/PendingBlock.ts

@@ -1,15 +1,14 @@
-import Node from './shared/Node';
-import Block from '../render-dom/Block';
 import map_children from './shared/map_children';
+import AbstractBlock from './shared/AbstractBlock';
 
-export default class PendingBlock extends Node {
-	block: Block;
-	children: Node[];
+export default class PendingBlock extends AbstractBlock {
 
 	constructor(component, parent, scope, info) {
 		super(component, parent, scope, info);
 		this.children = map_children(component, parent, scope, info.children);
 
+		if (!info.skip) {
 			this.warn_if_empty_block();
 		}
 	}
+}

src/compile/nodes/ThenBlock.ts

@@ -1,12 +1,9 @@
-import Node from './shared/Node';
-import Block from '../render-dom/Block';
 import map_children from './shared/map_children';
 import TemplateScope from './shared/TemplateScope';
+import AbstractBlock from './shared/AbstractBlock';
 
-export default class ThenBlock extends Node {
-	block: Block;
+export default class ThenBlock extends AbstractBlock {
 	scope: TemplateScope;
-	children: Node[];
 
 	constructor(component, parent, scope, info) {
 		super(component, parent, scope, info);
@@ -15,6 +12,8 @@ export default class ThenBlock extends Node {
 		this.scope.add(parent.value, parent.expression.dependencies, this);
 		this.children = map_children(component, parent, this.scope, info.children);
 
+		if (!info.skip) {
 			this.warn_if_empty_block();
 		}
 	}
+}

src/compile/nodes/shared/AbstractBlock.ts

@@ -0,0 +1,25 @@
+import Block from '../../render-dom/Block';
+import Component from './../../Component';
+import Node from './Node';
+
+export default class AbstractBlock extends Node {
+	block: Block;
+	children: Node[];
+
+	constructor(component: Component, parent, scope, info: any) {
+		super(component, parent, scope, info);
+	}
+
+	warn_if_empty_block() {
+		if (!this.children || this.children.length > 1) return;
+
+		const child = this.children[0];
+
+		if (!child || (child.type === 'Text' && !/[^ \r\n\f\v\t]/.test(child.data))) {
+			this.component.warn(this, {
+				code: 'empty-block',
+				message: 'Empty block'
+			});
+		}
+	}
+}

src/compile/nodes/shared/Node.ts

@@ -1,3 +1,4 @@
+import Attribute from './../Attribute';
 import Component from './../../Component';
 
 export default class Node {
@@ -12,6 +13,7 @@ export default class Node {
 
 	can_use_innerhtml: boolean;
 	var: string;
+	attributes: Attribute[];
 
 	constructor(component: Component, parent, scope, info: any) {
 		this.start = info.start;
@@ -64,18 +66,4 @@ export default class Node {
 			this.parent.type === type || this.parent.has_ancestor(type) :
 			false;
 	}
-
-	warn_if_empty_block() {
-		if (!/Block$/.test(this.type) || !this.children) return;
-		if (this.children.length > 1) return;
-
-		const child = this.children[0];
-
-		if (!child || (child.type === 'Text' && !/[^ \r\n\f\v\t]/.test(child.data))) {
-			this.component.warn(this, {
-				code: 'empty-block',
-				message: 'Empty block'
-			});
-		}
-	}
 }

src/index.ts

@@ -1,4 +1,6 @@
 export { default as compile } from './compile/index';
+export { default as parse } from './parse/index';
 export { default as preprocess } from './preprocess/index';
+export { walk } from 'estree-walker';
 
 export const VERSION = '__VERSION__';

src/interfaces.ts

@@ -61,6 +61,11 @@ export interface CompileOptions {
 	preserveWhitespace?: boolean;
 }
 
+export interface ParserOptions {
+	filename?: string;
+	customElement?: boolean;
+}
+
 export interface Visitor {
 	enter: (node: Node) => void;
 	leave?: (node: Node) => void;

src/parse/index.ts

@@ -3,14 +3,9 @@ import fragment from './state/fragment';
 import { whitespace } from '../utils/patterns';
 import { reserved } from '../utils/names';
 import full_char_code_at from '../utils/full_char_code_at';
-import { Node, Ast } from '../interfaces';
+import { Node, Ast, ParserOptions } from '../interfaces';
 import error from '../utils/error';
 
-interface ParserOptions {
-	filename?: string;
-	customElement?: boolean;
-}
-
 type ParserState = (parser: Parser) => (ParserState | void);
 
 export class Parser {

src/parse/state/mustache.ts

@@ -172,7 +172,8 @@ export default function mustache(parser: Parser) {
 				start,
 				end: null,
 				type: 'ThenBlock',
-				children: []
+				children: [],
+				skip: false
 			};
 
 			await_block.then = then_block;
@@ -196,7 +197,8 @@ export default function mustache(parser: Parser) {
 				start,
 				end: null,
 				type: 'CatchBlock',
-				children: []
+				children: [],
+				skip: false
 			};
 
 			await_block.catch = catch_block;
@@ -235,19 +237,22 @@ export default function mustache(parser: Parser) {
 					start: null,
 					end: null,
 					type: 'PendingBlock',
-					children: []
+					children: [],
+					skip: true
 				},
 				then: {
 					start: null,
 					end: null,
 					type: 'ThenBlock',
-					children: []
+					children: [],
+					skip: true
 				},
 				catch: {
 					start: null,
 					end: null,
 					type: 'CatchBlock',
-					children: []
+					children: [],
+					skip: true
 				},
 			} :
 			{
@@ -303,7 +308,15 @@ export default function mustache(parser: Parser) {
 		parser.stack.push(block);
 
 		if (type === 'AwaitBlock') {
-			const child_block = await_block_shorthand ? block.then : block.pending;
+			let child_block;
+			if (await_block_shorthand) {
+				block.then.skip = false;
+				child_block = block.then;
+			} else {
+				block.pending.skip = false;
+				child_block = block.pending;
+			}
+
 			child_block.start = parser.index;
 			parser.stack.push(child_block);
 		}

test/parser/samples/await-then-catch/output.json

@@ -19,6 +19,7 @@
 				"pending": {
 					"start": 19,
 					"end": 39,
+					"skip": false,
 					"type": "PendingBlock",
 					"children": [
 						{
@@ -53,6 +54,7 @@
 				"then": {
 					"start": 39,
 					"end": 88,
+					"skip": false,
 					"type": "ThenBlock",
 					"children": [
 						{
@@ -98,6 +100,7 @@
 				"catch": {
 					"start": 88,
 					"end": 140,
+					"skip": false,
 					"type": "CatchBlock",
 					"children": [
 						{

test/validator/samples/a11y-figcaption-in-non-element-block/input.svelte

@@ -0,0 +1,10 @@
+<script>
+	let caption = 'a foo in its natural habitat';
+</script>
+
+<figure>
+	<img src='foo.jpg' alt='a picture of a foo'>
+	{#if caption}
+		<figcaption>{caption}</figcaption>
+	{/if}
+</figure>

test/validator/samples/a11y-figcaption-in-non-element-block/warnings.json

@@ -0,0 +1 @@
+[]

test/validator/samples/await-no-catch/input.svelte

@@ -0,0 +1,9 @@
+<script>
+	let promise;
+</script>
+
+{#await promise}
+	<p>Loading</p>
+{:then data}
+	<p>Data: {data}</p>
+{/await}

test/validator/samples/await-no-catch/warnings.json

@@ -0,0 +1 @@
+[]

test/validator/samples/await-shorthand-no-catch/input.svelte

@@ -0,0 +1,7 @@
+<script>
+	let promise;
+</script>
+
+{#await promise then data}
+	<p>Data: {data}</p>
+{/await}

test/validator/samples/await-shorthand-no-catch/warnings.json

@@ -0,0 +1 @@
+[]