Incorrect type returned by c.req.param() #4384
Description
What version of Hono are you using?
4.9.5
What runtime/platform is your app running on? (with version if possible)
deno 2.4.x (but I assume same behavior on any)
What steps can reproduce the bug?
When using a router path that may be zero-length, c.req.param() may return undefined though its types only declare string.
Example:
#!/usr/bin/env -S deno run --check -N
import { Hono } from "npm:[email protected]"
const app = new Hono()
app.get("/:remaining{.*}", (c) => {
// Hono reports this as type `string`:
const remaining: string = c.req.param("remaining") // ⬅️ param name also type checked.
// However, with a root path of "/" we get `undefined`:
const lines = [
`type: ${typeof remaining}`,
`value: ${remaining}`,
]
return c.text(lines.join("\n"))
})
Deno.serve({port: 8080}, app.fetch)What is the expected behavior?
I expect:
- Returned types match the declared types
- I was expecting an empty string in this case.
What do you see instead?
undefined
(This can cause runtime exceptions in later code that expects the value to be a string.)
Additional information
No response