fix convertCase function

closes #93

Author: danivek

lib/JSONAPISerializer.js

@@ -795,61 +795,62 @@ module.exports = class JSONAPISerializer {
    * @returns {object} Object with it's keys converted as per the convertCaseOptions
    */
   _convertCase(data, convertCaseOptions) {
-    if (data !== undefined && data !== null) {
-      if (Array.isArray(data)) {
-        return data.map(item => this._convertCase(item, convertCaseOptions));
-      }
-
-      if (isPlainObject(data)) {
-        return transform(
-          data,
-          (result, value, key) => {
-            let converted;
-            if (value && Array.isArray(value)) {
-              converted = value.map(item => this._convertCase(item, convertCaseOptions));
-            } else if (value && isPlainObject(value)) {
-              converted = this._convertCase(value, convertCaseOptions);
-            } else {
-              converted = value;
-            }
+    if (Array.isArray(data)) {
+      return data.map(item => {
+        if (item && (Array.isArray(item) || isPlainObject(item))) {
+          return this._convertCase(item, convertCaseOptions);
+        }
+        return item;
+      });
+    }
 
-            result[this._convertCase(key, convertCaseOptions)] = converted;
-            return result;
-          },
-          {}
-        );
-      }
+    if (isPlainObject(data)) {
+      return transform(
+        data,
+        (result, value, key) => {
+          let converted;
+          if (value && (Array.isArray(value) || isPlainObject(value))) {
+            converted = this._convertCase(value, convertCaseOptions);
+          } else {
+            converted = value;
+          }
 
-      if (typeof data === 'string') {
-        let converted;
+          result[this._convertCase(key, convertCaseOptions)] = converted;
+          return result;
+        },
+        {}
+      );
+    }
 
-        switch (convertCaseOptions) {
-          case 'snake_case':
-            converted = this.convertCaseMap.snakeCase.get(data);
-            if (!converted) {
-              converted = toSnakeCase(data);
-              this.convertCaseMap.snakeCase.set(data, converted);
-            }
-            break;
-          case 'kebab-case':
-            converted = this.convertCaseMap.kebabCase.get(data);
-            if (!converted) {
-              converted = toKebabCase(data);
-              this.convertCaseMap.kebabCase.set(data, converted);
-            }
-            break;
-          case 'camelCase':
-            converted = this.convertCaseMap.camelCase.get(data);
-            if (!converted) {
-              converted = toCamelCase(data);
-              this.convertCaseMap.camelCase.set(data, converted);
-            }
-            break;
-          default: // Do nothing
-        }
+    if (typeof data === 'string') {
+      let converted;
 
-        return converted;
+      switch (convertCaseOptions) {
+        case 'snake_case':
+          converted = this.convertCaseMap.snakeCase.get(data);
+          if (!converted) {
+            converted = toSnakeCase(data);
+            this.convertCaseMap.snakeCase.set(data, converted);
+          }
+          break;
+        case 'kebab-case':
+          converted = this.convertCaseMap.kebabCase.get(data);
+          if (!converted) {
+            converted = toKebabCase(data);
+            this.convertCaseMap.kebabCase.set(data, converted);
+          }
+          break;
+        case 'camelCase':
+          converted = this.convertCaseMap.camelCase.get(data);
+          if (!converted) {
+            converted = toCamelCase(data);
+            this.convertCaseMap.camelCase.set(data, converted);
+          }
+          break;
+        default: // Do nothing
       }
+
+      return converted;
     }
 
     return data;

test/unit/JSONAPISerializer.test.js

@@ -2254,6 +2254,13 @@ describe('JSONAPISerializer', function() {
   })
 
  describe('convertCase', function() {
+  it('should return null', function() {
+    const jsonapiSerializer = new JSONAPISerializer();
+    const converted = jsonapiSerializer._convertCase(null, 'kebab-case');
+
+    expect(converted).to.equal(null);
+  });
+
   it('should convert an array of object to kebab-case', function() {
     const jsonapiSerializer = new JSONAPISerializer();
     const converted = jsonapiSerializer._convertCase(
@@ -2265,14 +2272,20 @@ describe('JSONAPISerializer', function() {
             thirdProperty: 0
           }
         ],
-        arrayOfNumber: [1, 2, 3, 4, 5]
+        arrayOfNumber: [1, 2, 3, 4, 5],
+        arrayOfString: ['firstString', 'secondString'],
+        normalProperty: 'normalProperty',
+        nullProperty: null,
       }],
       'kebab-case'
     );
 
     expect(converted).to.deep.equal([{
       'array-of-object': [{ 'first-property': 'test', 'second-property': null, 'third-property': 0 }],
-      'array-of-number': [1, 2, 3, 4, 5]
+      'array-of-number': [1, 2, 3, 4, 5],
+      'array-of-string': ['firstString', 'secondString'],
+      'normal-property': 'normalProperty',
+      'null-property': null
     }]);
   });
 
@@ -2288,13 +2301,19 @@ describe('JSONAPISerializer', function() {
           }
         ],
         arrayOfNumber: [1, 2, 3, 4, 5],
+        arrayOfString: ['firstString', 'secondString'],
+        normalProperty: 'normalProperty',
+        nullProperty: null,
         date: new Date()
       },
       'kebab-case'
     );
 
     expect(converted['array-of-object']).to.deep.equal([{ 'first-property': 'test', 'second-property': null, 'third-property': 0 }]);
     expect(converted['array-of-number']).to.deep.equal([1, 2, 3, 4, 5]);
+    expect(converted['array-of-string']).to.deep.equal(['firstString', 'secondString']);
+    expect(converted['normal-property']).to.equal('normalProperty');
+    expect(converted['null-property']).to.equal(null);
     expect(converted.date).to.be.a('Date');
   });
  });