Fixing const tag replacing memeber expressions properties.

src/compiler/compile/nodes/shared/Expression.ts

@@ -255,8 +255,11 @@ export default class Expression {
 
 					if (owner.type === 'ConstTag') {
 						walk(node, {
-							enter(node: Node) {
-								if (node.type === 'Identifier') {
+							enter(node: Node, parent: Node) {
+								if (node.type === 'Identifier' &&
+									  // ignore parts of member expressions,
+									  // in obj.key1.key2, Identifiers key1 and key2 should not be replaced
+									  (parent.type !== 'MemberExpression' || parent.property !== node)) {
 									this.replace(block.renderer.reference(node, ctx));
 								}
 							}

test/js/samples/const-tag/expected.js

@@ -0,0 +1,120 @@
+/* generated by Svelte vX.Y.Z */
+import {
+	SvelteComponent,
+	append,
+	destroy_block,
+	detach,
+	element,
+	empty,
+	init,
+	insert,
+	noop,
+	safe_not_equal,
+	set_data,
+	text,
+	update_keyed_each
+} from "svelte/internal";
+
+function get_each_context(ctx, list, i) {
+	const child_ctx = ctx.slice();
+	child_ctx[2] = list[i].id;
+	child_ctx[3] = list[i].thing;
+	const constants_0 = /*otherThings*/ child_ctx[1].find(ot => ot.id.id === /*id*/ child_ctx[2]);
+	child_ctx[4] = constants_0;
+	return child_ctx;
+}
+
+// (6:0) {#each things as {id, thing}
+function create_each_block(key_1, ctx) {
+	let div;
+	let t_value = /*thing*/ ctx[3].name + "";
+	let t;
+
+	return {
+		key: key_1,
+		first: null,
+		c() {
+			div = element("div");
+			t = text(t_value);
+			this.first = div;
+		},
+		m(target, anchor) {
+			insert(target, div, anchor);
+			append(div, t);
+		},
+		p(new_ctx, dirty) {
+			ctx = new_ctx;
+			if (dirty & /*things*/ 1 && t_value !== (t_value = /*thing*/ ctx[3].name + "")) set_data(t, t_value);
+		},
+		d(detaching) {
+			if (detaching) detach(div);
+		}
+	};
+}
+
+function create_fragment(ctx) {
+	let each_blocks = [];
+	let each_1_lookup = new Map();
+	let each_1_anchor;
+	let each_value = /*things*/ ctx[0];
+	const get_key = ctx => /*thing*/ ctx[3].id;
+
+	for (let i = 0; i < each_value.length; i += 1) {
+		let child_ctx = get_each_context(ctx, each_value, i);
+		let key = get_key(child_ctx);
+		each_1_lookup.set(key, each_blocks[i] = create_each_block(key, child_ctx));
+	}
+
+	return {
+		c() {
+			for (let i = 0; i < each_blocks.length; i += 1) {
+				each_blocks[i].c();
+			}
+
+			each_1_anchor = empty();
+		},
+		m(target, anchor) {
+			for (let i = 0; i < each_blocks.length; i += 1) {
+				each_blocks[i].m(target, anchor);
+			}
+
+			insert(target, each_1_anchor, anchor);
+		},
+		p(ctx, [dirty]) {
+			if (dirty & /*things*/ 1) {
+				each_value = /*things*/ ctx[0];
+				each_blocks = update_keyed_each(each_blocks, dirty, get_key, 1, ctx, each_value, each_1_lookup, each_1_anchor.parentNode, destroy_block, create_each_block, each_1_anchor, get_each_context);
+			}
+		},
+		i: noop,
+		o: noop,
+		d(detaching) {
+			for (let i = 0; i < each_blocks.length; i += 1) {
+				each_blocks[i].d(detaching);
+			}
+
+			if (detaching) detach(each_1_anchor);
+		}
+	};
+}
+
+function instance($$self, $$props, $$invalidate) {
+	let { things } = $$props;
+	let { otherThings } = $$props;
+
+	$$self.$$set = $$props => {
+		if ('things' in $$props) $$invalidate(0, things = $$props.things);
+		if ('otherThings' in $$props) $$invalidate(1, otherThings = $$props.otherThings);
+	};
+
+	return [things, otherThings];
+}
+
+class Component extends SvelteComponent {
+	constructor(options) {
+		super();
+		init(this, options, instance, create_fragment, safe_not_equal, { things: 0, otherThings: 1 });
+	}
+}
+
+export default Component;

test/js/samples/const-tag/input.svelte

@@ -0,0 +1,9 @@
+<script>
+	export let things;
+	export let otherThings;
+</script>
+
+{#each things as {id, thing} (thing.id)}
+	{@const otherThing = otherThings.find(ot => ot.id.id === id)}
+	<div>{thing.name}</div>
+{/each}