Fix union type alias sorting

packages/react-native-compatibility-check/src/SortTypeAnnotations.js

@@ -153,7 +153,8 @@ export function compareTypeAnnotationForSorting(
         [originalPositionB, typeB.elementType],
       );
     case 'TypeAliasTypeAnnotation':
-      return 0;
+      invariant(typeB.type === 'TypeAliasTypeAnnotation', EQUALITY_MSG);
+      return typeA.name.localeCompare(typeB.name);
     case 'MixedTypeAnnotation':
       return 0;
     default:

packages/react-native-compatibility-check/src/__tests__/ErrorFormattingTests.js

@@ -33,6 +33,10 @@ export const okayChanges = [
     'native-component-with-props/NativeComponent',
     'native-component-with-props-default-change/NativeComponent',
   ],
+  [
+    'native-module-with-union-object/NativeModule',
+    'native-module-with-union-object-added/NativeModule',
+  ],
 ];
 
 export const incompatibleChanges = [
@@ -130,6 +134,10 @@ export const incompatibleChanges = [
     'native-module-with-union-object/NativeModule',
     'native-module-with-union-object-changes/NativeModule',
   ],
+  [
+    'native-module-with-union-object-added/NativeModule',
+    'native-module-with-union-object/NativeModule',
+  ],
   [
     'native-component-with-command/NativeComponent',
     'native-component-with-command-changed/NativeComponent',

packages/react-native-compatibility-check/src/__tests__/VersionDiffing-test.js

@@ -118,6 +118,12 @@ const schemaWithUnionFromNative = makeRN(
 const schemaWithUnionFromNativeChanges = makeRN(
   'native-module-with-union-from-native-changes/NativeModule',
 );
+const schemaWithUnionObject = makeRN(
+  'native-module-with-union-object/NativeModule',
+);
+const schemaWithUnionObjectAdded = makeRN(
+  'native-module-with-union-object-added/NativeModule',
+);
 
 const schemaWithRNNativeComponent = makeRN('native-component/NativeComponent');
 const schemaNativeComponentWithCommand = makeRN(
@@ -1192,6 +1198,79 @@ describe('buildSchemaDiff', () => {
     );
   });
 
+  it('RN with union object types, and addition', () => {
+    const schemaDiff = buildSchemaDiff(
+      schemaWithUnionObjectAdded, // new: ObjectA | ObjectB | ObjectC
+      schemaWithUnionObject, // old: ObjectA | ObjectB
+    );
+
+    expect(summarizeDiffSet(schemaDiff).status).toBe('incompatible');
+    expect(schemaDiffExporter(Array.from(schemaDiff)[0])).toEqual(
+      expect.objectContaining({
+        framework: 'ReactNative',
+        name: 'NativeModule',
+        status: expect.objectContaining({
+          incompatibleSpecs: expect.arrayContaining([
+            expect.objectContaining({
+              changeInformation: expect.objectContaining({
+                incompatibleChanges: expect.arrayContaining([
+                  expect.objectContaining({
+                    errorCode: 'addedMemberCases',
+                  }),
+                ]),
+                objectTypeChanges: expect.arrayContaining([
+                  expect.objectContaining({
+                    propertyChange: expect.objectContaining({
+                      nestedPropertyChanges: expect.arrayContaining([
+                        [
+                          'exampleFunction',
+                          expect.objectContaining({
+                            status: 'functionChange',
+                            functionChangeLog: expect.objectContaining({
+                              parameterTypes: expect.objectContaining({
+                                nestedChanges: expect.arrayContaining([
+                                  [
+                                    0,
+                                    0,
+                                    expect.objectContaining({
+                                      status: 'members',
+                                      memberLog: expect.objectContaining({
+                                        memberKind: 'union',
+                                        addedMembers: expect.arrayContaining([
+                                          expect.objectContaining({
+                                            type: 'TypeAliasTypeAnnotation',
+                                            name: 'ObjectC',
+                                          }),
+                                        ]),
+                                      }),
+                                    }),
+                                  ],
+                                ]),
+                              }),
+                            }),
+                          }),
+                        ],
+                      ]),
+                    }),
+                  }),
+                ]),
+              }),
+            }),
+          ]),
+        }),
+      }),
+    );
+  });
+
+  it('RN with union object types, removal is ok', () => {
+    const schemaDiff = buildSchemaDiff(
+      schemaWithUnionObject, // new: ObjectA | ObjectB
+      schemaWithUnionObjectAdded, // old: ObjectA | ObjectB | ObjectC
+    );
+
+    expect(summarizeDiffSet(schemaDiff).status).toBe('ok');
+  });
+
   describe('NativeComponent', () => {
     it('module to component; deprecated + new', () => {
       expect(

packages/react-native-compatibility-check/src/__tests__/__fixtures__/native-module-with-union-object-added/NativeModule.js.flow

@@ -0,0 +1,41 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow
+ * @format
+ */
+
+import type {TurboModule} from 'react-native/Libraries/TurboModule/RCTExport';
+
+import * as TurboModuleRegistry from 'react-native/Libraries/TurboModule/TurboModuleRegistry';
+
+type ObjectA = {|
+  kind: 'a',
+  value: number,
+|};
+
+type ObjectB = {|
+  kind: 'b',
+  name: string,
+|};
+
+type ObjectC = {|
+  kind: 'c',
+  flag: boolean,
+|};
+
+type ObjectUnion = ObjectA | ObjectB | ObjectC;
+
+export interface Spec extends TurboModule {
+  +exampleFunction: (a: ObjectUnion, b: number) => void;
+  +getConstants: () => {
+    +exampleConstant: number,
+  };
+}
+
+export default (TurboModuleRegistry.getEnforcing<Spec>(
+  'NativeModuleTest',
+): Spec);

packages/react-native-compatibility-check/src/__tests__/__snapshots__/ErrorFormatting-test.js.snap

@@ -42,6 +42,13 @@ Object {
 }
 `;
 
+exports[`codegen formattedSummarizeDiffSet allows a diff from native-module-with-union-object-added/NativeModule to native-module-with-union-object/NativeModule 1`] = `
+Object {
+  "incompatibilityReport": Object {},
+  "status": "ok",
+}
+`;
+
 exports[`codegen formattedSummarizeDiffSet reports a diff from native-component-with-command/NativeComponent to native-component-with-command-extra-arg/NativeComponent 1`] = `
 Object {
   "incompatibilityReport": Object {
@@ -891,6 +898,31 @@ Object {
 }
 `;
 
+exports[`codegen formattedSummarizeDiffSet reports a diff from native-module-with-union-object/NativeModule to native-module-with-union-object-added/NativeModule 1`] = `
+Object {
+  "incompatibilityReport": Object {
+    "NativeModule": Object {
+      "framework": "ReactNative",
+      "incompatibleSpecs": Array [
+        Object {
+          "errorCode": "addedMemberCases",
+          "message": "NativeModuleTest: Object contained a property with a type mismatch
+  -- exampleFunction: has conflicting type changes
+      --new: (a: Union<mixed>, b: number)=>void
+      --old: (a: Union<mixed>, b: number)=>void
+      Parameter at index 0 did not match
+          --new: Union<mixed>
+          --old: Union<mixed>
+          Union added items, but native will not expect/support them
+              -- Member TypeAliasTypeAnnotation",
+        },
+      ],
+    },
+  },
+  "status": "incompatible",
+}
+`;
+
 exports[`codegen formattedSummarizeDiffSet reports a diff from native-module-with-union-object-changes/NativeModule to native-module-with-union-object/NativeModule 1`] = `
 Object {
   "incompatibilityReport": Object {