Implement the data model for web renderers v0.9

renderers/web_core/package.json

@@ -9,6 +9,10 @@
       "types": "./dist/src/v0_8/index.d.ts",
       "default": "./dist/src/v0_8/index.js"
     },
+    "./v0_9": {
+      "types": "./dist/src/v0_9/index.d.ts",
+      "default": "./dist/src/v0_9/index.js"
+    },
     "./types/*": {
       "types": "./dist/src/v0_8/types/*.d.ts",
       "default": "./dist/src/v0_8/types/*.js"
@@ -69,6 +73,7 @@
   "author": "Google",
   "license": "Apache-2.0",
   "devDependencies": {
+    "@types/node": "^24.10.1",
     "typescript": "^5.8.3",
     "wireit": "^0.15.0-pre.2"
   }

renderers/web_core/src/v0_9/state/data-model.test.ts

@@ -0,0 +1,203 @@
+
+import assert from 'node:assert';
+import { test, describe, it, beforeEach } from 'node:test';
+import { DataModel } from './data-model.js';
+
+describe('DataModel', () => {
+  let model: DataModel;
+
+  beforeEach(() => {
+    model = new DataModel({
+      user: {
+        name: 'Alice',
+        settings: {
+          theme: 'dark'
+        }
+      },
+      items: ['a', 'b', 'c']
+    });
+  });
+
+  // --- Basic Retrieval ---
+
+  it('retrieves root data', () => {
+    assert.deepStrictEqual(model.get('/'), { user: { name: 'Alice', settings: { theme: 'dark' } }, items: ['a', 'b', 'c'] });
+  });
+
+  it('retrieves nested path', () => {
+    assert.strictEqual(model.get('/user/name'), 'Alice');
+    assert.strictEqual(model.get('/user/settings/theme'), 'dark');
+  });
+
+  it('retrieves array items', () => {
+    assert.strictEqual(model.get('/items/0'), 'a');
+    assert.strictEqual(model.get('/items/1'), 'b');
+  });
+
+  it('returns undefined for non-existent paths', () => {
+    assert.strictEqual(model.get('/user/age'), undefined);
+    assert.strictEqual(model.get('/unknown/path'), undefined);
+  });
+
+  // --- Updates ---
+
+  it('sets value at existing path', () => {
+    model.set('/user/name', 'Bob');
+    assert.strictEqual(model.get('/user/name'), 'Bob');
+  });
+
+  it('sets value at new path', () => {
+    model.set('/user/age', 30);
+    assert.strictEqual(model.get('/user/age'), 30);
+  });
+
+  it('creates intermediate objects', () => {
+    model.set('/a/b/c', 'foo');
+    assert.strictEqual(model.get('/a/b/c'), 'foo');
+    assert.notStrictEqual(model.get('/a/b'), undefined);
+  });
+
+  it('removes keys when value is undefined', () => {
+    model.set('/user/name', undefined);
+    assert.strictEqual(model.get('/user/name'), undefined);
+    assert.strictEqual(Object.keys(model.get('/user')).includes('name'), false);
+  });
+
+  it('replaces root object on root update', () => {
+     model.set('/', { newRoot: true });
+     assert.deepStrictEqual(model.get('/'), { newRoot: true });
+  });
+
+  // --- Array / List Handling (Flutter Parity) ---
+
+  it('List: set and get', () => {
+    model.set('/list/0', 'hello');
+    assert.strictEqual(model.get('/list/0'), 'hello');
+    assert.ok(Array.isArray(model.get('/list')));
+  });
+
+  it('List: append and get', () => {
+    model.set('/list/0', 'hello');
+    model.set('/list/1', 'world');
+    assert.strictEqual(model.get('/list/0'), 'hello');
+    assert.strictEqual(model.get('/list/1'), 'world');
+    assert.strictEqual(model.get('/list').length, 2);
+  });
+
+  it('List: update existing index', () => {
+    model.set('/items/1', 'updated');
+    assert.strictEqual(model.get('/items/1'), 'updated');
+  });
+
+  it('Nested structures are created automatically', () => {
+    // Should create nested map and list: { a: { b: [ { c: 123 } ] } }
+    model.set('/a/b/0/c', 123);
+    assert.strictEqual(model.get('/a/b/0/c'), 123);
+    assert.ok(Array.isArray(model.get('/a/b')));
+    assert.ok(!Array.isArray(model.get('/a/b/0')));
+
+    // Should create nested maps
+    model.set('/x/y/z', 'hello');
+    assert.strictEqual(model.get('/x/y/z'), 'hello');
+
+    // Should create nested lists
+    model.set('/nestedList/0/0', 'inner');
+    assert.strictEqual(model.get('/nestedList/0/0'), 'inner');
+    assert.ok(Array.isArray(model.get('/nestedList')));
+    assert.ok(Array.isArray(model.get('/nestedList/0')));
+  });
+
+  // --- Subscriptions ---
+
+  it('returns a subscription object', () => {
+    model.set('/a', 1);
+    const sub = model.subscribe<number>('/a');
+    assert.strictEqual(sub.value, 1);
+
+    let updatedValue: number | undefined;
+    sub.onChange = (val) => updatedValue = val;
+
+    model.set('/a', 2);
+    assert.strictEqual(sub.value, 2);
+    assert.strictEqual(updatedValue, 2);
+
+    sub.unsubscribe();
+    // Verify listener removed
+    model.set('/a', 3);
+    assert.strictEqual(updatedValue, 2);
+  });
+
+  it('notifies subscribers on exact match', (_: any, done: (result?: any) => void) => {
+    const sub = model.subscribe('/user/name');
+    sub.onChange = (val) => {
+      assert.strictEqual(val, 'Charlie');
+      done();
+    };
+    model.set('/user/name', 'Charlie');
+  });
+
+  it('notifies ancestor subscribers (Container Semantics)', (_: any, done: (result?: any) => void) => {
+    const sub = model.subscribe('/user');
+    sub.onChange = (val: any) => {
+      assert.strictEqual(val.name, 'Dave');
+      done();
+    };
+    model.set('/user/name', 'Dave');
+  });
+
+  it('notifies descendant subscribers', (_: any, done: (result?: any) => void) => {
+    const sub = model.subscribe('/user/settings/theme');
+    sub.onChange = (val) => {
+      assert.strictEqual(val, 'light');
+      done();
+    };
+
+    // We update the parent object
+    model.set('/user/settings', { theme: 'light' });
+  });
+
+  it('notifies root subscriber', (_: any, done: (result?: any) => void) => {
+    const sub = model.subscribe('/');
+    sub.onChange = (val: any) => {
+      assert.strictEqual(val.newProp, 'test');
+      done();
+    };
+    model.set('/newProp', 'test');
+  });
+
+  it('notifies parent when child updates', () => {
+    model.set('/parent', { child: 'initial' });
+
+    const sub = model.subscribe('/parent');
+    let parentValue: any;
+    sub.onChange = (val) => parentValue = val;
+
+    model.set('/parent/child', 'updated');
+    assert.deepStrictEqual(parentValue, { child: 'updated' });
+  });
+
+  it('stops notifying after dispose', () => {
+    let count = 0;
+    const sub = model.subscribe('/');
+    sub.onChange = () => count++;
+
+    model.dispose();
+    model.set('/foo', 'bar');
+    assert.strictEqual(count, 0);
+  });
+
+  it('throws when trying to set nested property through a primitive', () => {
+    model.set('/user/name', 'not an object');
+    assert.strictEqual(model.get('/user/name'), 'not an object');
+
+    assert.throws(() => {
+        model.set('/user/name/first', 'Alice');
+    }, /Cannot set path/);
+  });
+
+  it('throws when using non-numeric segment on an array', () => {
+    assert.throws(() => {
+        model.set('/items/foo', 'bar');
+    }, /Cannot use non-numeric segment/);
+  });
+});