Add default value for blockRenderMap

Summary:
**Summary**

PR for issue 1211
facebookarchive/draft-js#1211

**Test Plan**

<s>no need</s>
**Edit by Flarnie:** added unit test
Closes facebookarchive/draft-js#1302

Reviewed By: zpao

Differential Revision: D5881334

Pulled By: zpao

fbshipit-source-id: b8d57b23a1654fe9cdcf84b74b25617413ef6248

package.json

@@ -30,6 +30,7 @@
     "test-ci": "NODE_ENV=test npm run lint && npm run flow && npm run test"
   },
   "dependencies": {
+    "enzyme": "^2.9.1",
     "fbjs": "^0.8.12",
     "immutable": "~3.7.4",
     "object-assign": "^4.1.0"

src/component/contents/DraftEditorContents.react.js

@@ -156,7 +156,10 @@ class DraftEditorContents extends React.Component<Props> {
         tree: editorState.getBlockTree(key),
       };
 
-      const configForType = blockRenderMap.get(blockType);
+      const configForType = (
+        blockRenderMap.get(blockType) ||
+        blockRenderMap.get('unstyled')
+      );
       const wrapperTemplate = configForType.wrapper;
 
       const Element = (

src/component/contents/__tests__/DraftEditorContent.react-test.js

@@ -0,0 +1,86 @@
+/**
+ * Copyright (c) 2013-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @emails oncall+ui_infra
+ * @typechecks
+ */
+
+'use strict';
+
+jest.disableAutomock();
+
+const Draft = require('Draft');
+const {Editor, EditorState, RichUtils} = Draft;
+const {mount} = require('enzyme');
+const React = require('react');
+
+describe('DraftEditor.react', () => {
+  describe('with a custom block type and the default blockRenderMap', () => {
+    it('defaults to "unstyled" block type for unknown block types', () => {
+      const CUSTOM_BLOCK_TYPE = 'CUSTOM_BLOCK_TYPE';
+
+      function CustomText(props) {
+        // contrived example
+        return <p><b>{props.children}</b></p>;
+      }
+
+      class Container extends React.Component {
+        constructor(props) {
+          super(props);
+          this.state = {
+            editorState: EditorState.createEmpty(),
+          };
+          this.toggleCustomBlock = this.toggleCustomBlock.bind(this);
+        }
+        toggleCustomBlock() {
+          this.setState({
+            editorState: RichUtils.toggleBlockType(
+              this.state.editorState,
+              CUSTOM_BLOCK_TYPE,
+            ),
+          }, () => {
+            setTimeout(() => this.focus(), 0);
+          });
+        }
+        blockRenderFn(block) {
+          if (block.getType() === CUSTOM_BLOCK_TYPE) {
+            return {
+              component: CustomText,
+              editable: true,
+            };
+          }
+          return null;
+        }
+        render() {
+          return (
+            <div className="container-root">
+              <div>
+                <button onClick={this.toggleCustomBlock}>CenterAlign</button>
+              </div>
+              <Editor
+                placeholder="Type away :)"
+                editorState={this.state.editorState}
+                blockRendererFn={this.blockRenderFn}
+                onChange={this._handleChange}
+              />
+            </div>
+          );
+        }
+        _handleChange = (editorState) => {
+          this.setState({editorState});
+        }
+      }
+
+      const mountedEditorContainer = mount(<Container />);
+      const triggerCustomBlockRender = () => {
+        mountedEditorContainer.find('button').simulate('click');
+      };
+      expect(triggerCustomBlockRender).not.toThrow();
+    });
+  });
+});