nushell/tests
Antoine Stevan 6c026242d4
remove the $nothing variable (#10478)
related to 
- https://github.com/nushell/nushell/pull/9973
- https://github.com/nushell/nushell/pull/9918

thanks to @jntrnr and their super useful tips on this PR, i learned
about the parser + evaluation, so 🙏

# Description
because we already have `null` as the value of the type `nothing` and as
a followup to the two other attempts of mine, i propose to remove the
redundant `$nothing` built-in variable 😋

this PR is the first step, deprecating `$nothing`.
a followup PR will remove it altogether and wait for 0.87 👍 

⚙️ **details**: a new `NOTHING_VARIABLE_ID = 3` has been added,
parsing `$nothing` will create it, finally a `Value::Nothing` will be
produced and a warning will be reported.

this PR already fixes the `toolkit.nu` module so that it does not throw
a bunch of warnings each time 👌

# User-Facing Changes
`$nothing` is now deprecated and will be removed in 0.87
```nushell
> $nothing
Error:   × Deprecated variable
   ╭─[entry #1:1:1]
 1 │ $nothing
   · ────┬───
   ·     ╰── `$nothing` is deprecated and will be removed in 0.87.
   ╰────
  help: Use `null` instead
```

# Tests + Formatting
tests have been updated, especially
- `nothing_fails_string`
- `nothing_fails_int`
which use a variable called `nil` now to make sure `nothing` does not
support cell paths 👍

# After Submitting
classic deprecation mention 👍
2023-09-26 18:49:28 +02:00
..
assets/nu_json Remove old nushell/merge engine-q 2022-02-07 14:54:06 -05:00
const_ remove the $nothing variable (#10478) 2023-09-26 18:49:28 +02:00
eval Exit early when encountering parsing errors (#10213) 2023-09-05 14:36:37 +02:00
fixtures Remove dead BSON related tests (#10458) 2023-09-21 20:01:49 +02:00
hooks Auto-expand table based on terminal width (#9934) 2023-08-08 05:47:23 -05:00
modules Recursively export constants from modules (#10049) 2023-08-20 14:51:35 +02:00
overlays Remove unnecessary cwd, pipeline(), r# from various tests (#9645) 2023-07-12 19:07:20 +02:00
parsing Fix default argument value type checking (#10460) 2023-09-24 11:30:58 +02:00
path Deref &String arguments to &str where appropriate (#10321) 2023-09-12 14:06:56 +08:00
plugins Disallow empty record with empty key,value pairs on ini format (#9722) 2023-07-18 22:14:18 +02:00
scope Add a few more fields to scope commands (#10045) 2023-08-18 20:47:38 +03:00
shell Update internal use of decimal to float (#10333) 2023-09-13 23:53:55 +02:00
main.rs prevent redefining fields in a record (#8705) 2023-04-02 06:09:33 +12:00