Add tests for ReactNativeAttributePayloadFabric.js

packages/react-native-renderer/src/ReactNativeAttributePayloadFabric.js

@@ -449,17 +449,24 @@ function fastAddProperties(
  props: Object,
  validAttributes: AttributeConfiguration,
 ): null | Object {
- let attributeConfig;
- let prop;
+ // Flatten nested style props.
+ if (isArray(props)) {
+ for (let i = 0; i < props.length; i++) {
+ payload = fastAddProperties(payload, props[i], validAttributes);
+ }
+ return payload;
+ }
 
  for (const propKey in props) {
- prop = props[propKey];
+ const prop = props[propKey];
 
  if (prop === undefined) {
  continue;
  }
 
- attributeConfig = ((validAttributes[propKey]: any): AttributeConfiguration);
+ const attributeConfig = ((validAttributes[
+ propKey
+ ]: any): AttributeConfiguration);
 
  if (attributeConfig == null) {
  continue;
@@ -477,7 +484,7 @@ function fastAddProperties(
  // An atomic prop with custom processing.
  newValue = attributeConfig.process(prop);
  } else if (typeof attributeConfig.diff === 'function') {
- // An atomic prop with custom diffing. We don't do diffing here.
+ // An atomic prop with custom diffing. We don't need to do diffing when adding props.
  newValue = prop;
  }
 
@@ -489,17 +496,6 @@ function fastAddProperties(
  continue;
  }
 
- // Not-atomic prop that needs to be flattened. Likely it's the 'style' prop.
-
- // It can be an array.
- if (isArray(prop)) {
- for (let i = 0; i < prop.length; i++) {
- payload = fastAddProperties(payload, prop[i], attributeConfig);
- }
- continue;
- }
-
- // Or it can be an object.
  payload = fastAddProperties(payload, prop, attributeConfig);
  }
 
@@ -514,11 +510,7 @@ function addProperties(
  props: Object,
  validAttributes: AttributeConfiguration,
 ): null | Object {
- if (enableAddPropertiesFastPath) {
- return fastAddProperties(updatePayload, props, validAttributes);
- } else {
- return diffProperties(updatePayload, emptyObject, props, validAttributes);
- }
+ return diffProperties(updatePayload, emptyObject, props, validAttributes);
 }
 
 /**
@@ -538,11 +530,11 @@ export function create(
  props: Object,
  validAttributes: AttributeConfiguration,
 ): null | Object {
- return addProperties(
- null, // updatePayload
-  props,
- validAttributes,
- );
+ if (enableAddPropertiesFastPath) {
+ return fastAddProperties(null, props, validAttributes);
+ } else {
+ return addProperties(null, props, validAttributes);
+ }
 }
 
 export function diff(