Add react-native support (#63)

Reviewed-on: https://home.schmelczer.dev/git/git/andras/reconcile/pulls/63

reconcile-js/src/index.test.ts

@@ -1,4 +1,5 @@
-import { reconcile, reconcileWithHistory, diff, undiff } from './index';
+import * as webApi from './index';
+import * as rnApi from './index.rn';
 import { installWasmLeakDetector, checkForWasmLeaks } from './wasm-leak-detector';
 import * as fs from 'fs';
 import * as path from 'path';
@@ -17,7 +18,18 @@ afterEach(() => {
   }
 });
 
-describe('reconcile', () => {
+// `./index` is the web/node build (real WebAssembly); `./index.rn` is the React
+// Native build (the wasm2js pure-JS translation). Both are thin backends over the
+// same `src/core.ts` wrapper and expose an identical public API, so the behavioural
+// suite below runs against both to guarantee they stay in lock-step.
+const backends = [
+  { name: 'web/node (WebAssembly)', api: webApi },
+  { name: 'React Native (wasm2js)', api: rnApi },
+];
+
+describe.each(backends)('reconcile [$name]', ({ api }) => {
+  const { reconcile, reconcileWithHistory, diff, undiff } = api;
+
   it('call reconcile without cursors', () => {
     expect(reconcile('Hello', 'Hello world', 'Hi world').text).toEqual('Hi world');
   });
@@ -60,9 +72,26 @@ describe('reconcile', () => {
     expect(result.text).toEqual('Hi world');
     expect(result.history.length).toBeGreaterThan(0);
   });
+
+  it('undiff accepts bigint entries (per the Array<number | bigint | string> type)', () => {
+    const original = 'Hello world';
+    const changed = 'Hello cruel world';
+
+    // `diff` returns plain numbers; emulate a caller that supplies BigInt, which the
+    // public signature permits. The wasm2js build rejects raw BigInt, so the shared
+    // wrapper must normalise it — running this on both backends asserts the contract.
+    const withBigints = diff(original, changed).map((item) =>
+      typeof item === 'number' ? BigInt(item) : item
+    );
+
+    expect(withBigints.some((item) => typeof item === 'bigint')).toBe(true);
+    expect(undiff(original, withBigints)).toEqual(changed);
+  });
 });
 
-describe('test_diff_and_undiff_are_inverse', () => {
+describe.each(backends)('diff and undiff are inverse [$name]', ({ api }) => {
+  const { diff, undiff } = api;
+
   const resourcesPath = path.join(__dirname, '../../tests/resources');
 
   const readFileSlice = (fileName: string, start: number, end: number): string => {
@@ -93,3 +122,31 @@ describe('test_diff_and_undiff_are_inverse', () => {
     });
   });
 });
+
+// React-Native-only: Hermes exposes no `WebAssembly` global, which is the whole reason
+// the RN entry point links a wasm2js build. Only the wasm2js backend can satisfy this.
+describe('React Native (wasm2js) Hermes parity', () => {
+  const { reconcile, reconcileWithHistory, diff, undiff } = rnApi;
+
+  it('runs every operation with no WebAssembly global', () => {
+    const descriptor = Object.getOwnPropertyDescriptor(globalThis, 'WebAssembly');
+    delete (globalThis as { WebAssembly?: unknown }).WebAssembly;
+    try {
+      expect((globalThis as { WebAssembly?: unknown }).WebAssembly).toBeUndefined();
+
+      expect(reconcile('Hello', 'Hello world', 'Hi world').text).toEqual('Hi world');
+
+      const changes = diff('Hello world', 'Hello cruel world');
+      expect(undiff('Hello world', changes)).toEqual('Hello cruel world');
+
+      expect(
+        reconcileWithHistory('Hello', 'Hello world', 'Hi world').history.length
+      ).toBeGreaterThan(0);
+    } finally {
+      // Restore the global so the leak check and later suites are unaffected.
+      if (descriptor) {
+        Object.defineProperty(globalThis, 'WebAssembly', descriptor);
+      }
+    }
+  });
+});