Set initialised per declarator

src/compile/utils/scope.ts

@@ -75,9 +75,8 @@ export class Scope {
 		if (node.kind === 'var' && this.block && this.parent) {
 			this.parent.add_declaration(node);
 		} else if (node.type === 'VariableDeclaration') {
-			const initialised = !!node.init;
-
 			node.declarations.forEach((declarator: Node) => {
+				const initialised = !!declarator.init;
 				extract_names(declarator.id).forEach(name => {
 					this.declarations.set(name, node);
 					if (initialised) this.initialised_declarations.add(name);

test/custom-elements/samples/no-warn-initialised-props/_config.js

@@ -0,0 +1,3 @@
+export default {
+	dev: true
+};

test/custom-elements/samples/no-warn-initialised-props/main.svelte

@@ -0,0 +1,7 @@
+<svelte:options tag="my-app"/>
+
+<script>
+	export let foo = undefined;
+</script>
+
+<p>foo: {foo}</p>

test/custom-elements/samples/no-warn-initialised-props/test.js

@@ -0,0 +1,17 @@
+import * as assert from 'assert';
+import './main.svelte';
+
+export default function (target) {
+	const warnings = [];
+	const warn = console.warn;
+
+	console.warn = warning => {
+		warnings.push(warning);
+	};
+
+	target.innerHTML = '<my-app />';
+
+	assert.equal(warnings.length, 0);
+
+	console.warn = warn;
+}