Issue 9/implement alternative paths

src/JsonProperty.ts

@@ -7,6 +7,7 @@ import { ReflectMetaDataKeys } from './common'
 type Params<P> = {
   path?: string
   paths?: string[]
+  pathAlternatives?: string[]
   required?: boolean
   type?:
     | (new (...args: any[]) => P)
@@ -53,11 +54,13 @@ export default function JsonProperty<P = unknown>(
         params.type || Reflect.getMetadata('design:type', target, propertyName),
     }
 
-    const existingMetadata: Record<string, JsonPropertyMetadata<P>> =
-      Reflect.getMetadata(
-        ReflectMetaDataKeys.TsJacksonJsonProperty,
-        target.constructor
-      ) || {}
+    const existingMetadata: Record<
+      string,
+      JsonPropertyMetadata<P>
+    > = Reflect.getMetadata(
+      ReflectMetaDataKeys.TsJacksonJsonProperty,
+      target.constructor
+    ) || {}
 
     existingMetadata[propertyName] = metadata
 

src/deserialize.test.ts

@@ -136,6 +136,28 @@ describe('deserialize', () => {
       )
     })
 
+    test('Class with path alternatives', () => {
+      @Serializable()
+      class TestClass {
+        @JsonProperty({ pathAlternatives: ['treat', 'goodie'] })
+        snack: string
+      }
+
+      const jsonTreat = {
+        treat: 'Scooby Snack',
+      }
+
+      const jsonGoodie = {
+        goodie: 'Sandwich',
+      }
+      const expected = new TestClass()
+      expected.snack = jsonTreat.treat
+      expect(deserialize(jsonTreat, TestClass)).toStrictEqual(expected)
+
+      expected.snack = jsonGoodie.goodie
+      expect(deserialize(jsonGoodie, TestClass)).toStrictEqual(expected)
+    })
+
     test('Class with one to one relation', () => {
       @Serializable()
       class Dog {

src/deserialize.ts

@@ -29,13 +29,11 @@ export default function deserialize<T, U extends Array<unknown>>(
   ...args: U
 ): T {
   assertSerializable(serializableClass)
-  const propsMetadata: Record<
-    string,
-    JsonPropertyMetadata
-  > = Reflect.getMetadata(
-    ReflectMetaDataKeys.TsJacksonJsonProperty,
-    serializableClass
-  )
+  const propsMetadata: Record<string, JsonPropertyMetadata> =
+    Reflect.getMetadata(
+      ReflectMetaDataKeys.TsJacksonJsonProperty,
+      serializableClass
+    )
   const resultClass = new serializableClass(...args)
   const jsonObject = typeof json === 'string' ? JSON.parse(json) : json
   const propertiesAfterDeserialize: {
@@ -44,9 +42,7 @@ export default function deserialize<T, U extends Array<unknown>>(
     afterDeserialize: JsonPropertyMetadata['afterDeserialize']
   }[] = []
   for (const [propName, propParams] of Object.entries(propsMetadata)) {
-    const jsonValue = propParams.paths
-      ? propParams.paths.map((path) => get(jsonObject, path))
-      : get(jsonObject, propParams.path)
+    const jsonValue = evaluateJsonValueByPath(jsonObject, propParams)
     propParams.required &&
       assertRequired({
         json: jsonObject,
@@ -136,3 +132,16 @@ function deserializeProperty(
     }
   }
 }
+
+function evaluateJsonValueByPath(
+  jsonObject: any,
+  propParams: JsonPropertyMetadata
+) {
+  if (propParams.paths)
+    return propParams.paths.map((path) => get(jsonObject, path))
+  if (propParams.pathAlternatives)
+    return propParams.pathAlternatives
+      .map((path) => get(jsonObject, path))
+      .find((value) => value != null)
+  return get(jsonObject, propParams.path)
+}