# Description
Fixes: #7298
So `try .. catch` works better on external command failed.
# User-Facing Changes
```
try {nu --testbin fail} catch {print "fail"}
```
After this pr, it will output "fail"
# Tests + Formatting
Don't forget to add tests that cover your changes.
Make sure you've run and fixed any issues with these commands:
- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass
# After Submitting
If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
Co-authored-by: JT <547158+jntrnr@users.noreply.github.com>
A small follow-up to #7221. This changes the `catch` block from a block
to a closure, so that it can access the error returned from the `try`
block. This helps with a common scenario: "the `try` block failed, and I
want to log why it failed."
### Example
![image](https://user-images.githubusercontent.com/26268125/203841966-f1f8f102-fd73-41e6-83bc-bf69ed436fa8.png)
### Future Work
Nu's closure syntax is a little awkward here; it might be nicer to allow
something like `catch err { print $err }`. We discussed this on Discord
and it will require special parser code similar to what's already done
for `for`.
I'm not feeling confident enough in my parser knowledge to make that
change; I will spend some more time looking at the `for` code but I
doubt I will be able to implement anything in the next few days.
Volunteers welcome.
# Description
This adds `try` (with an optional `catch` piece). Much like other
languages, `try` will try to run a block. If the block fails to run
successfully, the optional `catch` block will run if it is available.
# User-Facing Changes
This adds the `try` command.
# Tests + Formatting
Don't forget to add tests that cover your changes.
Make sure you've run and fixed any issues with these commands:
- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass
# After Submitting
If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.