BREAKING - Improve JS transform validation, add tests

Summary:
This improves JS validations of the transform object and makes it a bit stricter (hence the breaking change). When moving transform objects parsing to native (#10658) the validations got out of sync a bit, this makes sure JS validations are the same or stricter than the native ones to make sure we get consistent errors across platforms.

See #12110 for an example of an error that now gets caught by JS validations.

Also added snapshot tests for the errors to make sure `processTransform` throws when passing invalid values. It only tests the validation since the object parsing is now done natively for iOS and Android.

**Test plan**
Test that there are no errors in UIExplorer
Run new unit tests
Closes https://github.com/facebook/react-native/pull/12115

Differential Revision: D4488933

Pulled By: mkonicek

fbshipit-source-id: a714e6175b2892284a44c870506165099efec1ed

Libraries/StyleSheet/__tests__/__snapshots__/processTransform-test.js.snap

@@ -0,0 +1,27 @@
+exports[`processTransform validation should throw on invalid transform property 1`] = `"Invalid transform translateW: {\"translateW\":10}"`;
+
+exports[`processTransform validation should throw on object with multiple properties 1`] = `"You must specify exactly one property per transform object. Passed properties: {\"scale\":0.5,\"translateY\":10}"`;
+
+exports[`processTransform validation should throw when not passing an array to an array prop 1`] = `"Transform with key of matrix must have an array as the value: {\"matrix\":\"not-a-matrix\"}"`;
+
+exports[`processTransform validation should throw when not passing an array to an array prop 2`] = `"Transform with key of translate must have an array as the value: {\"translate\":10}"`;
+
+exports[`processTransform validation should throw when passing a matrix of the wrong size 1`] = `"Matrix transform must have a length of 9 (2d) or 16 (3d). Provided matrix has a length of 4: {\"matrix\":[1,1,1,1]}"`;
+
+exports[`processTransform validation should throw when passing a perspective of 0 1`] = `"Transform with key of \"perspective\" cannot be zero: {\"perspective\":0}"`;
+
+exports[`processTransform validation should throw when passing a translate of the wrong size 1`] = `"Transform with key translate must be an array of length 2 or 3, found 1: {\"translate\":[1]}"`;
+
+exports[`processTransform validation should throw when passing a translate of the wrong size 2`] = `"Transform with key translate must be an array of length 2 or 3, found 4: {\"translate\":[1,1,1,1]}"`;
+
+exports[`processTransform validation should throw when passing an Animated.Value 1`] = `"You passed an Animated.Value to a normal component. You need to wrap that component in an Animated. For example, replace <View /> by <Animated.View />."`;
+
+exports[`processTransform validation should throw when passing an invalid angle prop 1`] = `"Transform with key of \"rotate\" must be a string: {\"rotate\":10}"`;
+
+exports[`processTransform validation should throw when passing an invalid angle prop 2`] = `"Rotate transform must be expressed in degrees (deg) or radians (rad): {\"skewX\":\"10drg\"}"`;
+
+exports[`processTransform validation should throw when passing an invalid value to a number prop 1`] = `"Transform with key of \"translateY\" must be a number: {\"translateY\":\"20deg\"}"`;
+
+exports[`processTransform validation should throw when passing an invalid value to a number prop 2`] = `"Transform with key of \"scale\" must be a number: {\"scale\":{\"x\":10,\"y\":10}}"`;
+
+exports[`processTransform validation should throw when passing an invalid value to a number prop 3`] = `"Transform with key of \"perspective\" must be a number: {\"perspective\":[]}"`;

Libraries/StyleSheet/__tests__/processTransform-test.js

@@ -0,0 +1,86 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+'use strict';
+
+jest.disableAutomock();
+
+const processTransform = require('processTransform');
+
+describe('processTransform', () => {
+  describe('validation', () => {
+    it('should accept an empty array', () => {
+      processTransform([]);
+    });
+
+    it('should accept a simple valid transform', () => {
+      processTransform([
+        {scale: 0.5},
+        {translateX: 10},
+        {translateY: 20},
+        {rotate: '10deg'},
+      ]);
+    });
+
+    it('should throw on object with multiple properties', () => {
+      expect(() => processTransform([{scale: 0.5, translateY: 10}])).toThrowErrorMatchingSnapshot();
+    });
+
+    it('should throw on invalid transform property', () => {
+      expect(() => processTransform([{translateW: 10}])).toThrowErrorMatchingSnapshot();
+    });
+
+    it('should throw when not passing an array to an array prop', () => {
+      expect(() => processTransform([{matrix: 'not-a-matrix'}])).toThrowErrorMatchingSnapshot();
+      expect(() => processTransform([{translate: 10}])).toThrowErrorMatchingSnapshot();
+    });
+
+    it('should accept a valid matrix', () => {
+      processTransform([{matrix: [1, 1, 1, 1, 1, 1, 1, 1, 1]}]);
+      processTransform([{matrix: [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1]}]);
+    });
+
+    it('should throw when passing a matrix of the wrong size', () => {
+      expect(() => processTransform([{matrix: [1, 1, 1, 1]}])).toThrowErrorMatchingSnapshot();
+    });
+
+    it('should accept a valid translate', () => {
+      processTransform([{translate: [1, 1]}]);
+      processTransform([{translate: [1, 1, 1]}]);
+    });
+
+    it('should throw when passing a translate of the wrong size', () => {
+      expect(() => processTransform([{translate: [1]}])).toThrowErrorMatchingSnapshot();
+      expect(() => processTransform([{translate: [1, 1, 1, 1]}])).toThrowErrorMatchingSnapshot();
+    });
+
+    it('should throw when passing an invalid value to a number prop', () => {
+      expect(() => processTransform([{translateY: '20deg'}])).toThrowErrorMatchingSnapshot();
+      expect(() => processTransform([{scale: {x: 10, y: 10}}])).toThrowErrorMatchingSnapshot();
+      expect(() => processTransform([{perspective: []}])).toThrowErrorMatchingSnapshot();
+    });
+
+    it('should throw when passing a perspective of 0', () => {
+      expect(() => processTransform([{perspective: 0}])).toThrowErrorMatchingSnapshot();
+    });
+
+    it('should accept an angle in degrees or radians', () => {
+      processTransform([{skewY: '10deg'}]);
+      processTransform([{rotateX: '1.16rad'}]);
+    });
+
+    it('should throw when passing an invalid angle prop', () => {
+      expect(() => processTransform([{rotate: 10}])).toThrowErrorMatchingSnapshot();
+      expect(() => processTransform([{skewX: '10drg'}])).toThrowErrorMatchingSnapshot();
+    });
+
+    it('should throw when passing an Animated.Value', () => {
+      expect(() => processTransform([{rotate: {getValue: () => {}}}])).toThrowErrorMatchingSnapshot();
+    });
+  });
+});

Libraries/StyleSheet/processTransform.js

@@ -25,7 +25,7 @@ var stringifySafe = require('stringifySafe');
  * be applied in an arbitrary order, and yet have a universal, singular
  * interface to native code.
  */
-function processTransform(transform: Object): Object {
+function processTransform(transform: Array<Object>): Array<Object> | Array<number> {
   if (__DEV__) {
     _validateTransforms(transform);
   }
@@ -115,9 +115,15 @@ function _convertToRadians(value: string): number {
   return value.indexOf('rad') > -1 ? floatValue : floatValue * Math.PI / 180;
 }
 
-function _validateTransforms(transform: Object): void {
+function _validateTransforms(transform: Array<Object>): void {
   transform.forEach(transformation => {
-    var key = Object.keys(transformation)[0];
+    var keys = Object.keys(transformation);
+    invariant(
+      keys.length === 1,
+      'You must specify exactly one property per transform object. Passed properties: %s',
+      stringifySafe(transformation),
+    );
+    var key = keys[0];
     var value = transformation[key];
     _validateTransform(key, value, transformation);
   });
@@ -154,6 +160,12 @@ function _validateTransform(key, value, transformation) {
       );
       break;
     case 'translate':
+      invariant(
+        value.length === 2 || value.length === 3,
+        'Transform with key translate must be an array of length 2 or 3, found %s: %s',
+        value.length,
+        stringifySafe(transformation),
+      );
       break;
     case 'rotateX':
     case 'rotateY':
@@ -188,13 +200,20 @@ function _validateTransform(key, value, transformation) {
         stringifySafe(transformation),
       );
       break;
-    default:
+    case 'translateX':
+    case 'translateY':
+    case 'scale':
+    case 'scaleX':
+    case 'scaleY':
       invariant(
         typeof value === 'number',
         'Transform with key of "%s" must be a number: %s',
         key,
         stringifySafe(transformation),
       );
+      break;
+    default:
+      invariant(false, 'Invalid transform %s: %s', key, stringifySafe(transformation));
   }
 }