feat(json-crdt): 🎸 improve Model.create() schema inference from types

Author: streamich

src/json-crdt/model/Model.ts

@@ -1,15 +1,14 @@
 import * as operations from '../../json-crdt-patch/operations';
 import * as clock from '../../json-crdt-patch/clock';
-import {ConNode} from '../nodes/const/ConNode';
 import {encoder, decoder} from '../codec/structural/binary/shared';
 import {ModelApi} from './api';
 import {ORIGIN, SESSION, SYSTEM_SESSION_TIME} from '../../json-crdt-patch/constants';
 import {randomSessionId} from './util';
-import {RootNode, ValNode, VecNode, ObjNode, StrNode, BinNode, ArrNode} from '../nodes';
+import {ConNode, RootNode, ValNode, VecNode, ObjNode, StrNode, BinNode, ArrNode} from '../nodes';
 import {printTree} from 'tree-dump/lib/printTree';
 import {Extensions} from '../extensions/Extensions';
 import {AvlMap} from 'sonic-forest/lib/avl/AvlMap';
-import {NodeBuilder, s} from '../../json-crdt-patch';
+import {NodeBuilder, type nodes, s} from '../../json-crdt-patch';
 import type {SchemaToJsonNode} from '../schema/types';
 import type {JsonCrdtPatchOperation, Patch} from '../../json-crdt-patch/Patch';
 import type {JsonNode, JsonNodeView} from '../nodes/types';
@@ -126,16 +125,16 @@ export class Model<N extends JsonNode = JsonNode<any>> implements Printable {
   public static readonly create = <S extends NodeBuilder | unknown>(
     schema?: S,
     sidOrClock: clock.ClockVector | number = Model.sid(),
-  ): Model<S extends NodeBuilder ? SchemaToJsonNode<S> : JsonNode> => {
+  ) => {
     const cl =
       typeof sidOrClock === 'number'
         ? sidOrClock === SESSION.SERVER
           ? new clock.ServerClockVector(SESSION.SERVER, 1)
           : new clock.ClockVector(sidOrClock, 1)
         : sidOrClock;
-    type Node = S extends NodeBuilder ? SchemaToJsonNode<S> : JsonNode;
+    type Node = S extends undefined ? JsonNode : S extends NodeBuilder ? SchemaToJsonNode<S> : SchemaToJsonNode<nodes.json<S>>;
     const model = new Model<Node>(cl);
-    if (schema) model.setSchema(schema instanceof NodeBuilder ? schema : s.json(schema), true);
+    if (schema !== void 0) model.setSchema(schema instanceof NodeBuilder ? schema : s.json(schema), true);
     return model;
   };
 

src/json-crdt/model/__tests__/Model.schema.spec.ts

@@ -0,0 +1,88 @@
+import {type nodes, s} from '../../../json-crdt-patch';
+import {SESSION} from '../../../json-crdt-patch/constants';
+import {Model} from '../Model';
+
+describe('.setSchema()', () => {
+  test('can set object schema', () => {
+    const model = Model.create().setSchema(
+      s.obj({
+        str: s.str('asdf'),
+        con: s.con(123),
+      }),
+    );
+    expect(model.s.str.toApi().view()).toBe('asdf');
+    expect(model.s.con.toApi().view()).toBe(123);
+  });
+
+  test('can set map schema', () => {
+    const model = Model.create().setSchema(
+      s.map<nodes.str | nodes.con<number>>({
+        str: s.str('asdf'),
+        con1: s.con(123),
+      }),
+    );
+    expect(model.s.str.toApi().view()).toBe('asdf');
+    expect(model.s.con1.toApi().view()).toBe(123);
+    expect(model.view().str).toBe('asdf');
+    expect(model.view().con1).toBe(123);
+    expect(model.view().anyKeyAllowed).toBe(undefined);
+  });
+
+  test('uses global session ID by default', () => {
+    const model = Model.create().setSchema(
+      s.obj({
+        id: s.str<string>('asdf'),
+        num: s.con(123),
+      }),
+    );
+    expect(model.api.r.get().node.id.sid).toBe(SESSION.GLOBAL);
+    expect(model.api.r.get().get('id').node.id.sid).toBe(SESSION.GLOBAL);
+    expect(model.api.r.get().get('num').node.id.sid).toBe(SESSION.GLOBAL);
+  });
+
+  test('allows to specify custom session ID', () => {
+    const schema = s.obj({
+      id: s.str<string>('asdf'),
+      num: s.con(123),
+    });
+    const model = Model.create().setSchema(schema, false);
+    expect(model.api.r.get().node.id.sid).toBe(model.clock.sid);
+    expect(model.api.r.get().get('id').node.id.sid).toBe(model.clock.sid);
+    expect(model.api.r.get().get('num').node.id.sid).toBe(model.clock.sid);
+  });
+
+  test('resets session ID to user specified', () => {
+    const model = Model.create().setSchema(
+      s.obj({
+        id: s.str<string>('asdf'),
+        num: s.con(123),
+      }),
+    );
+    expect(model.view().num).toBe(123);
+    expect(model.api.r.get().get('num').node.id.sid).toBe(SESSION.GLOBAL);
+    model.api.r.get().set({
+      num: 456,
+    });
+    expect(model.view().num).toBe(456);
+    expect(model.api.r.get().get('num').node.id.sid).not.toBe(SESSION.GLOBAL);
+  });
+});
+
+describe('.create<Schema>()', () => {
+  test('infers schema from a pojo', () => {
+    const model = Model.create({
+      key1: 'value1',
+      key2: {
+        key3: [{
+          foo: 'bar',
+        }],
+      },
+    });
+    expect(model.$.key2.key3[0].foo.$?.view()).toBe('bar');
+  });
+
+  test('when schema not set, does not strictly type accessor', () => {
+    const model = Model.create(void 0);
+    expect(model.$.key2.key3[0].foo.$?.view()).toBe(undefined);
+  });
+});