only run create() for new if blocks - fixes #665

src/generators/dom/visitors/IfBlock.ts

@@ -173,8 +173,10 @@ function simple(
 			`
 		: branch.hasIntroMethod
 			? deindent`
-				if ( !${name} ) ${name} = ${branch.block}( ${params}, ${block.component} );
-				${name}.create();
+				if ( !${name} ) {
+					${name} = ${branch.block}( ${params}, ${block.component} );
+					${name}.create();
+				}
 				${name}.intro( ${parentNode}, ${anchor} );
 			`
 			: deindent`

test/runtime/samples/transition-js-if-block-in-each-block-bidi/_config.js

@@ -0,0 +1,45 @@
+export default {
+	data: {
+		threshold: 5
+	},
+
+	html: `
+		<div>1</div>
+		<div>2</div>
+		<div>3</div>
+		<div>4</div>
+		<div>5</div>
+	`,
+
+	test ( assert, component, target, window, raf ) {
+		const divs = target.querySelectorAll('div');
+
+		assert.equal(divs[0].foo, 0);
+
+		raf.tick(100);
+		assert.equal(divs[0].foo, 1);
+
+		component.set({ threshold: 4 });
+		assert.equal( divs[4].foo, 1 );
+
+		raf.tick( 200 );
+		assert.htmlEqual(target.innerHTML, `
+			<div>1</div>
+			<div>2</div>
+			<div>3</div>
+			<div>4</div>
+		`);
+
+		component.set({ threshold: 3 });
+		assert.equal( divs[3].foo, 1 );
+
+		raf.tick( 300 );
+		assert.htmlEqual(target.innerHTML, `
+			<div>1</div>
+			<div>2</div>
+			<div>3</div>
+		`);
+
+		component.destroy();
+	}
+};

test/runtime/samples/transition-js-if-block-in-each-block-bidi/main.html

@@ -0,0 +1,20 @@
+{{#each [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] as number}} 
+	{{#if threshold >= number}}
+		<div transition:foo>{{number}}</div>
+	{{/if}}
+{{/each}}
+
+<script>
+	export default {
+		transitions: {
+			foo: function ( node ) {
+				return {
+					duration: 100,
+					tick: t => {
+						node.foo = t;
+					}
+				};
+			}
+		}
+	};
+</script>