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TypeScript Compiler compiles Generic ArrowFunction into a TsxElementΒ #60474
Description
π Search Terms
- generic
- array
- function
- compile
- tsxelement
π Version & Regression Information
- This is the behavior in typescript@next version I tried
β― Playground Link
π» Code
ArrayFunction is compatible with Generics, is there a bug in TypeScript Compiler or is the usage introduced in TypeScript Deep Dive incorrect?
The following compilers compiled to ArrayFunction:
- babel-eslint9
- @babel/parser
- esformatter
- flow
- hermes-parser
Use the following code from the TypeScript Deep Dive:
const getJSON = <T>(config: {
url: string,
headers?: { [key: string]: string },
}): Promise<T> => {
const fetchConfig = ({
method: 'GET',
'Accept': 'application/json',
'Content-Type': 'application/json',
...(config.headers || {})
});
return fetch(config.url, fetchConfig)
.then<T>(response => response.json());
};π Actual behavior
Result transpiled to JavaScript:
"use strict";
const getJSON = React.createElement(T, null,
"(config: ",
url,
" string, headers?: ",
[key],
" string]: string }, }): Promise",
React.createElement(T, null,
" => ",
,
" fetchConfig = (",
method,
" 'GET', 'Accept': 'application/json', 'Content-Type': 'application/json', ...(config.headers || ",
") }); return fetch(config.url, fetchConfig) .then",
React.createElement(T, null, "(response => response.json()); };")));π Expected behavior
"use strict";
const getJSON = (config) => {
const fetchConfig = (Object.assign({ method: 'GET', 'Accept': 'application/json', 'Content-Type': 'application/json' }, (config.headers || {})));
return fetch(config.url, fetchConfig)
.then(response => response.json());
};Additional information about the issue
No response
Activity
MartinJohns commentedon Nov 11, 2024
This is working as intended / a design limitation due to the ambigious syntax for jsx elements and generics. You either need to disable jsx in your config, or use the workaround syntax
<T,>instead of<T>for your generic.typescript-bot commentedon Nov 15, 2024
This issue has been marked as "Working as Intended" and has seen no recent activity. It has been automatically closed for house-keeping purposes.