Add failure tests for duplicate props with the same name

Summary: There are a couple of cases where props can conflict which would cause undefined behavior. We'll throw to protect against that. Now that we support type spread this is more possible without someone realizing.

Reviewed By: JoshuaGross

Differential Revision: D16813884

fbshipit-source-id: 1a8fce365ab315198abdff0de6006cfe34e84fb9

Author: elicwhite

packages/react-native-codegen/src/parsers/flow/components/__test_fixtures__/failures.js

@@ -305,6 +305,104 @@ export default (codegenNativeComponent<ModuleProps>(
 ): NativeComponent<ModuleProps>);
 `;
 
+const PROPS_CONFLICT_NAMES = `
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ * @flow
+ */
+
+'use strict';
+
+import type {ViewProps} from 'ViewPropTypes';
+import type {NativeComponent} from 'codegenNativeComponent';
+
+const codegenNativeComponent = require('codegenNativeComponent');
+
+export type ModuleProps = $ReadOnly<{|
+  ...ViewProps,
+  isEnabled: string,
+
+  isEnabled: boolean,
+|}>;
+
+export default (codegenNativeComponent<ModuleProps>(
+  'Module',
+): NativeComponent<ModuleProps>);
+`;
+
+const PROPS_CONFLICT_WITH_SPREAD_PROPS = `
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ * @flow
+ */
+
+'use strict';
+
+import type {ViewProps} from 'ViewPropTypes';
+import type {NativeComponent} from 'codegenNativeComponent';
+
+const codegenNativeComponent = require('codegenNativeComponent');
+
+type PropsInFile = $ReadOnly<{|
+  isEnabled: boolean,
+|}>;
+
+export type ModuleProps = $ReadOnly<{|
+  ...ViewProps,
+
+  ...PropsInFile,
+  isEnabled: boolean,
+|}>;
+
+export default (codegenNativeComponent<ModuleProps>(
+  'Module',
+): NativeComponent<ModuleProps>);
+`;
+
+const PROPS_SPREAD_CONFLICTS_WITH_PROPS = `
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ * @flow
+ */
+
+'use strict';
+
+import type {ViewProps} from 'ViewPropTypes';
+import type {NativeComponent} from 'codegenNativeComponent';
+
+const codegenNativeComponent = require('codegenNativeComponent');
+
+type PropsInFile = $ReadOnly<{|
+  isEnabled: boolean,
+|}>;
+
+export type ModuleProps = $ReadOnly<{|
+  ...ViewProps,
+
+  isEnabled: boolean,
+  ...PropsInFile,
+|}>;
+
+export default (codegenNativeComponent<ModuleProps>(
+  'Module',
+): NativeComponent<ModuleProps>);
+`;
+
 module.exports = {
   COMMANDS_DEFINED_INLINE,
   COMMANDS_DEFINED_MULTIPLE_TIMES,
@@ -314,4 +412,7 @@ module.exports = {
   COMMANDS_DEFINED_WITH_NULLABLE_REF,
   NULLABLE_WITH_DEFAULT,
   NON_OPTIONAL_KEY_WITH_DEFAULT_VALUE,
+  PROPS_CONFLICT_NAMES,
+  PROPS_CONFLICT_WITH_SPREAD_PROPS,
+  PROPS_SPREAD_CONFLICTS_WITH_PROPS,
 };

packages/react-native-codegen/src/parsers/flow/components/__tests__/__snapshots__/component-parser-test.js.snap

@@ -16,6 +16,12 @@ exports[`RN Codegen Flow Parser Fails with error message NON_OPTIONAL_KEY_WITH_D
 
 exports[`RN Codegen Flow Parser Fails with error message NULLABLE_WITH_DEFAULT 1`] = `"WithDefault<> is optional and does not need to be marked as optional. Please remove the ? annotation in front of it."`;
 
+exports[`RN Codegen Flow Parser Fails with error message PROPS_CONFLICT_NAMES 1`] = `"A prop was already defined with the name isEnabled"`;
+
+exports[`RN Codegen Flow Parser Fails with error message PROPS_CONFLICT_WITH_SPREAD_PROPS 1`] = `"A prop was already defined with the name isEnabled"`;
+
+exports[`RN Codegen Flow Parser Fails with error message PROPS_SPREAD_CONFLICTS_WITH_PROPS 1`] = `"A prop was already defined with the name isEnabled"`;
+
 exports[`RN Codegen Flow Parser can generate fixture ALL_PROP_TYPES_NO_EVENTS 1`] = `
 Object {
   "modules": Object {

packages/react-native-codegen/src/parsers/flow/components/props.js

@@ -302,6 +302,17 @@ function buildPropSchema(property, types: TypeMap): ?PropTypeShape {
 // $FlowFixMe there's no flowtype for ASTs
 type PropAST = Object;
 
+function verifyPropNotAlreadyDefined(
+  props: $ReadOnlyArray<PropAST>,
+  needleProp: PropAST,
+) {
+  const propName = needleProp.key.name;
+  const foundProp = props.some(prop => prop.key.name === propName);
+  if (foundProp) {
+    throw new Error(`A prop was already defined with the name ${propName}`);
+  }
+}
+
 function flattenProperties(
   typeDefinition: $ReadOnlyArray<PropAST>,
   types: TypeMap,
@@ -319,8 +330,12 @@ function flattenProperties(
     })
     .reduce((acc, item) => {
       if (Array.isArray(item)) {
+        item.forEach(prop => {
+          verifyPropNotAlreadyDefined(acc, prop);
+        });
         return acc.concat(item);
       } else {
+        verifyPropNotAlreadyDefined(acc, item);
         acc.push(item);
         return acc;
       }