Allow a max depth to be passed to Resource#toJSON

Author: rubensworks

lib/Resource.ts

@@ -100,21 +100,21 @@ export class Resource {
   /**
    * Create a convenient JSON representation of a Resource.
    */
-  public toJSON(): any {
+  public toJSON(maxDepth = -1): any {
     if (Object.keys(this.properties).length === 0 && !this.list) {
       return termToString(this.term);
     }
     return {
       '@id': termToString(this.term),
-      ...Object.keys(this.properties).length > 0 ?
+      ...maxDepth !== 0 && Object.keys(this.properties).length > 0 ?
         {
           properties: Object.keys(this.properties).reduce((acc: any, key) => {
-            acc[key] = this.properties[key].map(resource => resource.toJSON());
+            acc[key] = this.properties[key].map(resource => resource.toJSON(maxDepth - 1));
             return acc;
           }, {}),
         } :
         {},
-      ...this.list ? { list: this.list.map(resource => resource.toJSON()) } : {},
+      ...maxDepth !== 0 && this.list ? { list: this.list.map(resource => resource.toJSON(maxDepth - 1)) } : {},
     };
   }
 

test/Resource-test.ts

@@ -151,6 +151,136 @@ describe('Resource', () => {
           ],
         });
       });
+
+      it('with nested list and properties and no max depth', () => {
+        const value1 = new Resource({ term: DF.namedNode('ex:value1') });
+        const value1_1 = new Resource({ term: DF.namedNode('ex:value1.1') });
+        const value1_1_1 = new Resource({ term: DF.namedNode('ex:value1.1.1') });
+        value1_1.properties['ex:a.1.1'].push(value1_1_1);
+        value1.properties['ex:a.1'].push(value1_1);
+        resource.properties['ex:a'].push(value1);
+        resource.properties['ex:b'].push(new Resource({ term: DF.literal('value2') }));
+        resource.list = [];
+        resource.list.push(value1);
+        resource.list.push(new Resource({ term: DF.literal('value2') }));
+        expect(resource.toJSON()).toEqual({
+          '@id': 'http://example.org/resource1',
+          properties: {
+            'http://example.org/a': [
+              {
+                '@id': 'ex:value1',
+                properties: {
+                  'ex:a.1': [
+                    {
+                      '@id': 'ex:value1.1',
+                      properties: {
+                        'ex:a.1.1': [
+                          'ex:value1.1.1',
+                        ],
+                      },
+                    },
+                  ],
+                },
+              },
+            ],
+            'http://example.org/b': [
+              '"value2"',
+            ],
+          },
+          list: [
+            {
+              '@id': 'ex:value1',
+              properties: {
+                'ex:a.1': [
+                  {
+                    '@id': 'ex:value1.1',
+                    properties: {
+                      'ex:a.1.1': [
+                        'ex:value1.1.1',
+                      ],
+                    },
+                  },
+                ],
+              },
+            },
+            '"value2"',
+          ],
+        });
+      });
+
+      it('with nested list and properties and a max depth of 1', () => {
+        const value1 = new Resource({ term: DF.namedNode('ex:value1') });
+        const value1_1 = new Resource({ term: DF.namedNode('ex:value1.1') });
+        const value1_1_1 = new Resource({ term: DF.namedNode('ex:value1.1.1') });
+        value1_1.properties['ex:a.1.1'].push(value1_1_1);
+        value1.properties['ex:a.1'].push(value1_1);
+        resource.properties['ex:a'].push(value1);
+        resource.properties['ex:b'].push(new Resource({ term: DF.literal('value2') }));
+        resource.list = [];
+        resource.list.push(value1);
+        resource.list.push(new Resource({ term: DF.literal('value2') }));
+        expect(resource.toJSON(1)).toEqual({
+          '@id': 'http://example.org/resource1',
+          properties: {
+            'http://example.org/a': [
+              { '@id': 'ex:value1' },
+            ],
+            'http://example.org/b': [
+              '"value2"',
+            ],
+          },
+          list: [
+            { '@id': 'ex:value1' },
+            '"value2"',
+          ],
+        });
+      });
+
+      it('with nested list and properties and a max depth of 2', () => {
+        const value1 = new Resource({ term: DF.namedNode('ex:value1') });
+        const value1_1 = new Resource({ term: DF.namedNode('ex:value1.1') });
+        const value1_1_1 = new Resource({ term: DF.namedNode('ex:value1.1.1') });
+        value1_1.properties['ex:a.1.1'].push(value1_1_1);
+        value1.properties['ex:a.1'].push(value1_1);
+        resource.properties['ex:a'].push(value1);
+        resource.properties['ex:b'].push(new Resource({ term: DF.literal('value2') }));
+        resource.list = [];
+        resource.list.push(value1);
+        resource.list.push(new Resource({ term: DF.literal('value2') }));
+        expect(resource.toJSON(2)).toEqual({
+          '@id': 'http://example.org/resource1',
+          properties: {
+            'http://example.org/a': [
+              {
+                '@id': 'ex:value1',
+                properties: {
+                  'ex:a.1': [
+                    {
+                      '@id': 'ex:value1.1',
+                    },
+                  ],
+                },
+              },
+            ],
+            'http://example.org/b': [
+              '"value2"',
+            ],
+          },
+          list: [
+            {
+              '@id': 'ex:value1',
+              properties: {
+                'ex:a.1': [
+                  {
+                    '@id': 'ex:value1.1',
+                  },
+                ],
+              },
+            },
+            '"value2"',
+          ],
+        });
+      });
     });
   });