Enhancing a theme component can only be done once #4530
Description
🐛 Bug Report
If more than one plugin enhances a theme component (https://docusaurus.io/docs/using-themes/#for-plugin-authors), such as docusaurus-theme-live-codeblock, subsequent enhancers past the first will receive undefined for the imported component to enhance from @theme-init
Have you read the Contributing Guidelines on issues?
Yes
To Reproduce
- Install the
@docusaurus/theme-live-codeblockpackage - Activate it twice in docusaurus.config.js (to simulate more than one plugin enhancing
CodeBlock):
themes: [
["@docusaurus/theme-live-codeblock", { id: "2" }],
["@docusaurus/theme-live-codeblock", { id: "1" }]
],
docusaurus start- Receive errors in the console. This is caused by this import returning undefined for the second theme definition:
index.js?a908:1 Warning: React.createElement: type is invalid -- expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in, or you might have mixed up default and named imports.
Check the render method of `WrappedComponent`.
at WrappedComponent (webpack-internal:///./node_modules/@docusaurus/theme-live-codeblock/src/theme/CodeBlock/index.js:13:77)
at pre (webpack-internal:///../node_modules/@docusaurus/theme-classic/lib-next/theme/MDXComponents/index.js:12:598)
at MDXCreateElement (webpack-internal:///../node_modules/@mdx-js/react/dist/esm.js:153:30)
at wrapper (webpack-internal:///../node_modules/@mdx-js/react/dist/esm.js:148:25)
at MDXCreateElement (webpack-internal:///../node_modules/@mdx-js/react/dist/esm.js:153:30)
at MDXContent (webpack-internal:///./docs/optimize/dev/react/getting-started.mdx:12:1329)
<snip>
Expected behavior
You can have more than one theme enhancing a given component (i.e. the second theme instance would enhance the component enhanced by the first instance).
Actual Behavior
Importing the component after one enhancement gives undefined.
Your Environment
- Docusaurus version used: 2.0.0-alpha.72
- CodeSandbox + node 14, windows 10 + node 14