Make TimingAnimationConfig read-only

Summary:
Makes `TimingAnimationConfig` read-only, as it's purely an input type.

Changelog: [Internal]

Reviewed By: yungsters

Differential Revision: D34146703

fbshipit-source-id: 77ac7ee0641a869b62e5f95b6a7f711c71e82c7d

Libraries/Animated/AnimatedImplementation.js

@@ -91,7 +91,7 @@ const diffClamp = function (
 
 const _combineCallbacks = function (
   callback: ?EndCallback,
-  config: {...AnimationConfig, ...},
+  config: $ReadOnly<{...AnimationConfig, ...}>,
 ) {
   if (callback && config.onComplete) {
     return (...args) => {

Libraries/Animated/NativeAnimatedHelper.js

@@ -368,7 +368,7 @@ function assertNativeAnimatedModule(): void {
 let _warnedMissingNativeAnimated = false;
 
 function shouldUseNativeDriver(
-  config: {...AnimationConfig, ...} | EventConfig,
+  config: $ReadOnly<{...AnimationConfig, ...}> | EventConfig,
 ): boolean {
   if (config.useNativeDriver == null) {
     console.warn(

Libraries/Animated/animations/TimingAnimation.js

@@ -23,7 +23,7 @@ import type {RgbaValue} from '../nodes/AnimatedColor';
 
 import AnimatedColor from '../nodes/AnimatedColor';
 
-export type TimingAnimationConfig = {
+export type TimingAnimationConfig = $ReadOnly<{
   ...AnimationConfig,
   toValue:
     | number
@@ -40,15 +40,15 @@ export type TimingAnimationConfig = {
   easing?: (value: number) => number,
   duration?: number,
   delay?: number,
-};
+}>;
 
-export type TimingAnimationConfigSingle = {
+export type TimingAnimationConfigSingle = $ReadOnly<{
   ...AnimationConfig,
   toValue: number | AnimatedValue | AnimatedInterpolation,
   easing?: (value: number) => number,
   duration?: number,
   delay?: number,
-};
+}>;
 
 let _easeInOut;
 function easeInOut() {