Warn when invalid "unstable" value in deno.jsonc

[littledivy]

{
  "tasks": {
    "start": "deno run index.js"
  },
  "unstable": [
    "abc"
  ]
}

deno task start

This should warn that "abc" is not a valid unstable feature. There is no indication where the feature is being used or not.

[bartlomieju]

This seems like a simple fix, but I'm not sure where we use this configuration to decide on unstable features. @dsherret maybe you could provide some pointers?

[dsherret]

Maybe we should just warn here?

https://github.com/denoland/deno/blob/47232f8a41532a7ea3ed05c87b52bbd66a68cdab/cli/args/mod.rs#L696

[littledivy]

Maybe we can use #[serde(deny_unknown_fields)] for the config and print the error?

[Hasan-Alrimawi]

Hello @dsherret, I'd like to to give this issue a shot.

But, can you please confirm if the valid unstable features are the following? Since I'll refer to them in solving the issue.

1. (UNSTABLE_GRANULAR_FLAGS) can be found in deno/runtime/lib.rs
2. bare_node_builtins
3. byonm
4. sloppy_imports All the preceding unstable flags were mentioned within this link: https://docs.deno.com/runtime/manual/tools/unstable_flags