reactjs / reactjs/react-docgen
TypeScript: Missing Union Elements of Indexed Access Type
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Description
Hello there,
In the following code, the elements of the size props are not outputted.
type Base = {
size: "small" | "medium" | "large";
};
type Props = {
size: Base["size"];
}
const MyComponent = ({size}: Props) => {
return <div />;
}
Result
[
{
"description": "",
"displayName": "MyComponent",
"methods": [],
"props": {
"size": {
"required": true,
"tsType": {
"name": "union",
"raw": "Base[\"size\"]"
},
"description": ""
}
}
}
]
Expected Behavior
[
{
"description": "",
"displayName": "MyComponent",
"methods": [],
"props": {
"size": {
"required": true,
"tsType": {
"name": "union",
"raw": "\"small\" | \"medium\" | \"large\"",
"elements": [
{
"name": "literal",
"value": "\"small\""
},
{
"name": "literal",
"value": "\"medium\""
},
{
"name": "literal",
"value": "\"large\""
}
]
},
"description": ""
}
}
}
]
I reproduced it here:
https://react-docgen.dev/playground
Thanks for regards.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the TypeScript example in the issue and reproduce it in the react-docgen playground. Trace how the indexed-access type is handled, then add coverage for the expected union literal elements and confirm the generated JSON includes the three literals shown.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- react, typescript
- Domain
- documentation, tooling
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100