React DraftJS WYSIWYG prism syntax highlight

highlight.js

const convertContent = content => {
    const blockMap = content.getBlockMap();
    let newBlockMap = Map();

    blockMap.valueSeq().forEach(block => {
        if (block.getType() === 'code') {
            const data = block.getData().merge({ language: 'javascript' });
            const newBlock = block.merge({ type: 'code-block', data });
            newBlockMap = newBlockMap.set(block.key, newBlock);
        }
    });

    const newContent = content.merge({
        blockMap: blockMap.merge(newBlockMap)
    });

    return newContent;
};