improve toJSON() return type.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@colyseus/schema",
-  "version": "2.0.12",
+  "version": "2.0.13",
   "description": "Binary state serializer with delta encoding for games",
   "bin": {
     "schema-codegen": "./bin/schema-codegen"

src/Schema.ts

@@ -11,7 +11,7 @@ import { CollectionSchema } from './types/CollectionSchema';
 import { SetSchema } from './types/SetSchema';
 
 import { ChangeTree, Ref, ChangeOperation } from "./changes/ChangeTree";
-import { NonFunctionPropNames } from './types/HelperTypes';
+import { NonFunctionPropNames, ToJSON } from './types/HelperTypes';
 import { ClientState } from './filters';
 import { getType } from './types/typeRegistry';
 import { ReferenceTracker } from './changes/ReferenceTracker';
@@ -184,7 +184,7 @@ export abstract class Schema {
     }
 
     public assign(
-        props: { [prop in NonFunctionPropNames<this>]?: this[prop] }
+        props: { [prop in NonFunctionPropNames<this>]?: this[prop] } | ToJSON<this>,
     ) {
         Object.assign(this, props);
         return this;
@@ -898,7 +898,7 @@ export abstract class Schema {
         const schema = this._definition.schema;
         const deprecated = this._definition.deprecated;
 
-        const obj = {}
+        const obj: ToJSON<typeof this> = {};
         for (let field in schema) {
             if (!deprecated[field] && this[field] !== null && typeof (this[field]) !== "undefined") {
                 obj[field] = (typeof (this[field]['toJSON']) === "function")

src/types/HelperTypes.ts

@@ -1,34 +1,18 @@
-type Bool = 'true' | 'false'
-type Key = string | number | symbol;
+import { ArraySchema } from "./ArraySchema";
+import { MapSchema } from "./MapSchema";
 
-type Not<X extends Bool> = {
-    true: 'false',
-    false: 'true'
-}[X]
-
-type HaveIntersection<S1 extends string, S2 extends string> = (
-    { [K in S1]: 'true' } &
-    { [key: string]: 'false' }
-)[S2]
-
-type IsNeverWorker<S extends Key> = (
-    { [K in S]: 'false' } &
-    { [key: string]: 'true' }
-)[S]
-
-// Worker needed because of https://github.com/Microsoft/TypeScript/issues/18118
-type IsNever<T extends Key> = Not<HaveIntersection<IsNeverWorker<T>, 'false'>>
-
-type IsFunction<T> = IsNever<keyof T>
-
-export type NonFunctionProps<T> = {
-    [K in keyof T]: {
-        'false': K,
-        'true': never
-    }[IsFunction<T[K]>]
-}[keyof T];
+export type NonFunctionProps<T> = Omit<T, {
+    [K in keyof T]: T[K] extends Function ? K : never;
+}[keyof T]>;
 
 export type NonFunctionPropNames<T> = {
     [K in keyof T]: T[K] extends Function ? never : K
 }[keyof T];
 
+export type ToJSON<T> = Partial<NonFunctionProps<{
+    [K in keyof T]: T[K] extends MapSchema<infer U>
+        ? Record<string, U>
+        : T[K] extends ArraySchema<infer U>
+            ? U[]
+            : T[K]
+}>>;

test/SchemaTest.ts

@@ -973,7 +973,7 @@ describe("Schema Usage", () => {
 
             state.value.set('k1', 1);
             const firstEncoded = state.encodeAll();
-            
+
             const decodedState1 = new TestMapSchema();
             decodedState1.decode(firstEncoded);
             assert.deepStrictEqual(decodedState1.toJSON(), state.toJSON(), `decodedState1.toJSON() EQ state.toJSON()`);