fix: sending null values when attributes were not provided from backend

fix: jsonmodelconverter providing model instead of array

Author: Michael Dostál

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "angular2-jsonapi",
-  "version": "6.0.5-beta",
+  "version": "6.0.6-beta",
   "description": "A lightweight Angular 2 adapter for JSON API",
   "scripts": {
     "build": "rimraf dist src/compiled && tslint src/**/*.ts && ngc",

package.json

@@ -8,7 +8,7 @@ describe('JsonModel converter', () => {
 
     describe('ArrayModel - simple values', () => {
       beforeEach(() => {
-        converter = new JsonModelConverter(Array);
+        converter = new JsonModelConverter(Array, { hasMany: true });
       });
 
       it('should return empty array when empty input', () => {
@@ -34,10 +34,23 @@ describe('JsonModel converter', () => {
       });
     });
 
+    describe('ArrayModel - simple values - nullable', () => {
+      beforeEach(() => {
+        converter = new JsonModelConverter(Array, { hasMany: true, nullValue: true });
+      });
+
+      it('should throw error when provided empty array when empty input', () => {
+        const VALUE = null;
+        expect(() => {
+          converter.mask(VALUE);
+        }).toThrow(new Error('ERROR: JsonModelConverter: Expected array but got ' + typeof VALUE + '.'));
+      });
+    });
+
     describe('Array model -> object values', () => {
 
       beforeEach(() => {
-        converter = new JsonModelConverter(School);
+        converter = new JsonModelConverter(School, { hasMany: true });
       });
 
       it('should return array of Schools from provided data', () => {
@@ -83,7 +96,7 @@ describe('JsonModel converter', () => {
 
     describe('ObjectModel - nullable', () => {
       beforeEach(() => {
-        converter = new JsonModelConverter(School, false);
+        converter = new JsonModelConverter(School, { nullValue: false });
       });
 
       it('should return null when null', () => {
@@ -96,7 +109,7 @@ describe('JsonModel converter', () => {
   describe('unmask method', () => {
     describe('ArrayModel - simple values', () => {
       beforeEach(() => {
-        converter = new JsonModelConverter(Array);
+        converter = new JsonModelConverter(Array, { hasMany: true });
       });
 
       it('should return serialized output when provided null', () => {
@@ -120,7 +133,7 @@ describe('JsonModel converter', () => {
     describe('Array model -> object values', () => {
 
       beforeEach(() => {
-        converter = new JsonModelConverter(School);
+        converter = new JsonModelConverter(School, { hasMany: true });
       });
 
       it('should return serialized Schools from provided Array of Schools', () => {
@@ -129,7 +142,7 @@ describe('JsonModel converter', () => {
           { name: 'Charles University', students: 51438, foundation: '1348-04-07' },
         ];
         const schools: Array<School> = [new School(DATA[0]), new School(DATA[1])];
-        const result:Array<any> = converter.unmask(schools);
+        const result: Array<any> = converter.unmask(schools);
         expect(result.length).toBe(2);
         for (const key in result) {
           expect(result[key].name).toBe(DATA[key].name);
@@ -141,7 +154,7 @@ describe('JsonModel converter', () => {
 
     describe('ObjectModel - nullable', () => {
       beforeEach(() => {
-        converter = new JsonModelConverter(School, false);
+        converter = new JsonModelConverter(School, { nullValue: false });
       });
 
       it('should return null when null', () => {

src/converters/json-model/json-model.converter.spec.ts

@@ -1,19 +1,33 @@
 import { JsonApiNestedModel, PropertyConverter } from '../..';
+import { JsonModelConverterConfig } from '../../interfaces/json-model-converter-config.interface';
+
+export const DEFAULT_OPTIONS: JsonModelConverterConfig = {
+  nullValue: false,
+  hasMany: false
+};
 
 export class JsonModelConverter<T> implements PropertyConverter {
   private modelType: any; // ModelType<T>
+  private options: JsonModelConverterConfig;
 
-  constructor(model: T, public nullValue: boolean = true) {
+  constructor(model: T, options: JsonModelConverterConfig = {}) {
     this.modelType = model; // <ModelType<T>>model
+    this.options = { ...DEFAULT_OPTIONS, ...options };
   }
 
-  mask(value: any): T {
-    if (!value && !this.nullValue) {
+  mask(value: any): T | Array<T> {
+    if (!value && !this.options.nullValue) {
+      if (this.options.hasMany) {
+        return [];
+      }
       return new this.modelType();
     }
 
     let result = null;
-    if (Array.isArray(value)) {
+    if (this.options.hasMany) {
+      if (!Array.isArray(value)) {
+        throw new Error('ERROR: JsonModelConverter: Expected array but got ' + typeof value + '.');
+      }
       result = [];
       for (const item of value) {
         if (item === null) {

src/converters/json-model/json-model.converter.ts

@@ -72,7 +72,7 @@ export function Attribute(options: AttributeDecoratorOptions = {}): PropertyDeco
     const setter = function (newVal: any) {
       const targetType = Reflect.getMetadata('design:type', target, propertyName);
       const convertedValue = converter(targetType, newVal);
-      let oldValue = undefined;
+      let oldValue = null;
       if (this.isModelInitialization() && this.id) {
         oldValue = converter(targetType, newVal);
       } else {

src/decorators/attribute.decorator.ts

@@ -16,6 +16,7 @@ export * from './models/error-response.model';
 export * from './models/json-api-query-data';
 
 export * from './interfaces/overrides.interface';
+export * from './interfaces/json-model-converter-config.interface';
 export * from './interfaces/datastore-config.interface';
 export * from './interfaces/model-config.interface';
 export * from './interfaces/attribute-decorator-options.interface';

src/index.ts

@@ -0,0 +1,4 @@
+export interface JsonModelConverterConfig {
+  nullValue?: boolean;
+  hasMany?: boolean;
+}