From 3c98ba79858dfab4735c0357b16ee5fdf078be21 Mon Sep 17 00:00:00 2001
From: Rich Harris <richard.a.harris@gmail.com>
Date: Sun, 3 Dec 2017 14:30:25 -0500
Subject: [PATCH] parse :Switch tags

---
 src/parse/state/tag.ts                        | 35 +++++++++------
 .../samples/component-dynamic/input.html      |  1 +
 .../samples/component-dynamic/output.json     | 43 +++++++++++++++++++
 3 files changed, 66 insertions(+), 13 deletions(-)
 create mode 100644 test/parser/samples/component-dynamic/input.html
 create mode 100644 test/parser/samples/component-dynamic/output.json

diff --git a/src/parse/state/tag.ts b/src/parse/state/tag.ts
index ffe9a40218..d2c17e30fa 100644
--- a/src/parse/state/tag.ts
+++ b/src/parse/state/tag.ts
@@ -15,9 +15,10 @@ import { Node } from '../../interfaces';
 const validTagName = /^\!?[a-zA-Z]{1,}:?[a-zA-Z0-9\-]*/;
 
 const SELF = ':Self';
+const SWITCH = ':Switch';
 
 const metaTags = {
-	':Window': true,
+	':Window': true
 };
 
 const specials = new Map([
@@ -104,6 +105,15 @@ export default function tag(parser: Parser) {
 		}
 	}
 
+	const element: Node = {
+		start,
+		end: null, // filled in later
+		type: 'Element',
+		name,
+		attributes: [],
+		children: [],
+	};
+
 	parser.allowWhitespace();
 
 	if (isClosingTag) {
@@ -156,12 +166,18 @@ export default function tag(parser: Parser) {
 		}
 	}
 
-	const attributes = [];
+	if (name === SWITCH) {
+		parser.eat('{', true);
+		element.expression = readExpression(parser);
+		parser.allowWhitespace();
+		parser.eat('}', true);
+	}
+
 	const uniqueNames = new Set();
 
 	let attribute;
 	while ((attribute = readAttribute(parser, uniqueNames))) {
-		attributes.push(attribute);
+		element.attributes.push(attribute);
 		parser.allowWhitespace();
 	}
 
@@ -179,19 +195,10 @@ export default function tag(parser: Parser) {
 		}
 
 		parser.eat('>', true);
-		parser[special.property] = special.read(parser, start, attributes);
+		parser[special.property] = special.read(parser, start, element.attributes);
 		return;
 	}
 
-	const element: Node = {
-		start,
-		end: null, // filled in later
-		type: 'Element',
-		name,
-		attributes,
-		children: [],
-	};
-
 	parser.current().children.push(element);
 
 	const selfClosing = parser.eat('/') || isVoidElementName(name);
@@ -242,6 +249,8 @@ function readTagName(parser: Parser) {
 		return SELF;
 	}
 
+	if (parser.eat(SWITCH)) return SWITCH;
+
 	const name = parser.readUntil(/(\s|\/|>)/);
 
 	if (name in metaTags) return name;
diff --git a/test/parser/samples/component-dynamic/input.html b/test/parser/samples/component-dynamic/input.html
new file mode 100644
index 0000000000..1c4e872902
--- /dev/null
+++ b/test/parser/samples/component-dynamic/input.html
@@ -0,0 +1 @@
+<:Switch {foo ? Foo : Bar}></:Switch>
\ No newline at end of file
diff --git a/test/parser/samples/component-dynamic/output.json b/test/parser/samples/component-dynamic/output.json
new file mode 100644
index 0000000000..22b32bb932
--- /dev/null
+++ b/test/parser/samples/component-dynamic/output.json
@@ -0,0 +1,43 @@
+{
+	"hash": 755548012,
+	"html": {
+		"start": 0,
+		"end": 37,
+		"type": "Fragment",
+		"children": [
+			{
+				"start": 0,
+				"end": 37,
+				"type": "Element",
+				"name": ":Switch",
+				"attributes": [],
+				"children": [],
+				"expression": {
+					"type": "ConditionalExpression",
+					"start": 10,
+					"end": 25,
+					"test": {
+						"type": "Identifier",
+						"start": 10,
+						"end": 13,
+						"name": "foo"
+					},
+					"consequent": {
+						"type": "Identifier",
+						"start": 16,
+						"end": 19,
+						"name": "Foo"
+					},
+					"alternate": {
+						"type": "Identifier",
+						"start": 22,
+						"end": 25,
+						"name": "Bar"
+					}
+				}
+			}
+		]
+	},
+	"css": null,
+	"js": null
+}
\ No newline at end of file