fix: empty collections will render to null

Author: olexiyk

src/JSONLDAbstractNode.js

@@ -11,7 +11,13 @@ class JSONLDAbstractNode extends React.Component {
   };
 
   getChildJSON(child) {
-    if (!child) return null;
+    if (!child) {
+      return null;
+    }
+
+    if (Array.isArray(child) && child.length === 0) {
+      return null;
+    }
 
     const ChildClass = child.type;
     const { children, type, id, ...schema } = child.props;
@@ -28,7 +34,9 @@ class JSONLDAbstractNode extends React.Component {
   }
 
   parseChildren() {
-    if (!this.props.children) return {};
+    if (!this.props.children) {
+      return {};
+    }
     /*
      * If a component has a single child, this.props.children is a Child object.
      * If a component has multiple children, this.props.children is an array of Child objects.
@@ -39,7 +47,8 @@ class JSONLDAbstractNode extends React.Component {
         .map(child => this.getChildJSON(child))
         .filter(child => child);
     }
-    return [this.getChildJSON(this.props.children)];
+    const childJSON = this.getChildJSON(this.props.children);
+    return childJSON ? [childJSON] : null;
   }
 
   render() {

src/core/__tests__/GenericNodeCollection.test.js

@@ -30,4 +30,34 @@ describe("GenerticNodeCollection", () => {
       )
     ).toMatchSnapshot();
   });
+  it("do not render empty collection", () => {
+    expect(
+      renderer.create(
+        <JSONLD>
+          <GenericNode
+            type="review"
+            jsonldtype="Review"
+            name="With empty collection"
+          >
+            <GenericNodeCollection type="author" />
+          </GenericNode>
+        </JSONLD>
+      )
+    ).toMatchSnapshot();
+  });
+  it("do not render collection of empty array in it", () => {
+    expect(
+      renderer.create(
+        <JSONLD>
+          <GenericNode
+            type="review"
+            jsonldtype="Review"
+            name="With collection of empty array in it"
+          >
+            <GenericNodeCollection type="author">{[]}</GenericNodeCollection>
+          </GenericNode>
+        </JSONLD>
+      )
+    ).toMatchSnapshot();
+  });
 });

src/core/__tests__/__snapshots__/GenericNodeCollection.test.js.snap

@@ -1,5 +1,21 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`GenerticNodeCollection do not render collection of empty array in it 1`] = `
+<script
+  type="application/ld+json"
+>
+  {"@context":"https://schema.org/","@type":"Review","name":"With collection of empty array in it","author":null}
+</script>
+`;
+
+exports[`GenerticNodeCollection do not render empty collection 1`] = `
+<script
+  type="application/ld+json"
+>
+  {"@context":"https://schema.org/","@type":"Review","name":"With empty collection","author":null}
+</script>
+`;
+
 exports[`GenerticNodeCollection filters out null and false nodes from a collection 1`] = `
 <script
   type="application/ld+json"