avoid magical accessors

packages/svelte/src/internal/server/index.js

@@ -94,7 +94,7 @@ function close(head, body, payload) {
 		cleanup();
 	}
 
-	head += payload.global.head.title.value;
+	head += payload.global.head.get_title();
 
 	body = BLOCK_OPEN + body + BLOCK_CLOSE; // this inserts a fake boundary so hydration matches
 
@@ -698,7 +698,7 @@ export function build_title(payload, children) {
 	payload.compact({
 		start: i,
 		fn: ({ head }) => {
-			payload.global.head.title = { path, value: head };
+			payload.global.head.set_title(head, path);
 			// since we can only ever render the title in this chunk, and title rendering is handled specially,
 			// we can just ditch the results after we've saved them globally
 			return { head: '', body: '' };

packages/svelte/src/internal/server/payload.js

@@ -397,27 +397,32 @@ export class TreeHeadState {
 	 */
 	#title = { path: [], value: '' };
 
-	get title() {
-		return this.#title;
+	get_title() {
+		return this.#title.value;
 	}
 
-	set title(value) {
+	/**
+	 * Performs a depth-first (lexicographic) comparison using the path. Rejects sets
+	 * from earlier than or equal to the current value.
+	 * @param {string} value
+	 * @param {number[]} path
+	 */
+	set_title(value, path) {
 		// perform a depth-first (lexicographic) comparison using the path. Reject sets
 		// from earlier than or equal to the current value.
-		const contender_path = value.path;
 		const current_path = this.#title.path;
 
-		const max_len = Math.max(contender_path.length, current_path.length);
+		const max_len = Math.max(path.length, current_path.length);
 		for (let i = 0; i < max_len; i++) {
-			const contender_segment = contender_path[i];
+			const contender_segment = path[i];
 			const current_segment = current_path[i];
 
 			// contender shorter than current and all previous segments equal -> earlier
 			if (contender_segment === undefined) return;
 			// current shorter than contender and all previous segments equal -> contender is later
 			if (current_segment === undefined || contender_segment > current_segment) {
-				this.#title.path = value.path;
-				this.#title.value = value.value;
+				this.#title.path = path;
+				this.#title.value = value;
 				return;
 			}
 			if (contender_segment < current_segment) return;

packages/svelte/src/internal/server/payload.test.ts

@@ -170,7 +170,7 @@ test('subsume replaces tree content and state from other', () => {
 		$$payload.push('body');
 	});
 	b.global.css.add({ hash: 'h', code: 'c' });
-	b.global.head.title = { path: [1], value: 'Title' };
+	b.global.head.set_title('Title', [1]);
 	b.local.select_value = 'B';
 	b.promises.initial = Promise.resolve();
 
@@ -192,7 +192,7 @@ test('subsume refuses to switch modes', () => {
 		$$payload.push('body');
 	});
 	b.global.css.add({ hash: 'h', code: 'c' });
-	b.global.head.title = { path: [1], value: 'Title' };
+	b.global.head.set_title('Title', [1]);
 	b.local.select_value = 'B';
 	b.promises.initial = Promise.resolve();
 
@@ -209,28 +209,28 @@ test('TreeState uid generator uses prefix', () => {
 test('TreeHeadState title ordering favors later lexicographic paths', () => {
 	const head = new TreeHeadState(() => '');
 
-	head.title = { path: [1], value: 'A' };
-	assert.equal(head.title.value, 'A');
+	head.set_title('A', [1]);
+	assert.equal(head.get_title(), 'A');
 
 	// equal path -> unchanged
-	head.title = { path: [1], value: 'B' };
-	assert.equal(head.title.value, 'A');
+	head.set_title('B', [1]);
+	assert.equal(head.get_title(), 'A');
 
 	// earlier -> unchanged
-	head.title = { path: [0, 9], value: 'C' };
-	assert.equal(head.title.value, 'A');
+	head.set_title('C', [0, 9]);
+	assert.equal(head.get_title(), 'A');
 
 	// later -> update
-	head.title = { path: [2], value: 'D' };
-	assert.equal(head.title.value, 'D');
+	head.set_title('D', [2]);
+	assert.equal(head.get_title(), 'D');
 
 	// longer but same prefix -> update
-	head.title = { path: [2, 0], value: 'E' };
-	assert.equal(head.title.value, 'E');
+	head.set_title('E', [2, 0]);
+	assert.equal(head.get_title(), 'E');
 
 	// shorter (earlier) than current with same prefix -> unchanged
-	head.title = { path: [2], value: 'F' };
-	assert.equal(head.title.value, 'E');
+	head.set_title('F', [2]);
+	assert.equal(head.get_title(), 'E');
 });
 
 test('push accepts async functions in async context', async () => {