'blockRenderMap' may cause unhandled exception when 'blockRenderFn' is provided

[southerncross]

Do you want to request a feature or report a bug?

Bug

What is the current behavior?

I want to create a block type to center text, so I defined a new block type 'CENTER_BLOCK_TYPE' and a new blockRenderFn.

But I got an error: Uncaught TypeError: Cannot read property 'wrapper' of undefined.
(Draft 0.10.1)

The online example is: https://jsfiddle.net/m6z0xn4r/191/

After debugging for a while, I noticed that it was the blockRenderMap that caused the exception.

const configForType = blockRenderMap.get(blockType); // 'configForType' will be undefined
const wrapperTemplate = configForType.wrapper; // can not read wrapper of undefined

(https://github.com/facebook/draft-js/blob/master/src/component/contents/DraftEditorContents.react.js#L147)

Since I didn't provide customized blockRenderMap, so the exception occurred when Draft tried to find out the wrapper.

I think it is not a normal behavior, because according to Draft's doc:

Any block that is not recognized by the block redering mapping will be treated as unstyled

So I think the code should be changed as:

const configForType = blockRenderMap.get(blockType) || blockRenderMap.get('unstyled'); // add a default value
const wrapperTemplate = configForType.wrapper;

[hellendag]

That seems like a reasonable solution. Feel free to send a PR, it sounds like it'll be a simple one to merge.

[southerncross]

No problem 😄

[mitermayer]

This issue has been already fixed by 3da87b5