Douglas 029f3843d3
Add default --empty to handle empty values (#15223)
# Description

Adds a new `--empty/-e` flag to the `default` command.

# User-Facing Changes

Before:

```nushell
$env.FOO = ""
$env.FOO = $env.FOO? | default bar
$env.FOO
# => Empty string
```

After:

```nushell
$env.FOO = ""
$env.FOO = $env.FOO? | default -e bar
$env.FOO
# => bar
```

* Uses `val.is_empty`, which means that empty lists and records are also
replaced
* Empty values in tables (with a column specifier) are also replaced.

# Tests + Formatting

7 tests added and 1 updated + 1 new example

- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`

# After Submitting

N/A
2025-03-13 19:50:50 +01:00
..
2024-11-29 21:24:17 +00:00
2025-01-28 16:03:31 -06:00
2025-01-07 07:37:51 +08:00
2025-02-03 06:33:23 -06:00
2025-02-12 20:03:40 -08:00
2025-02-04 10:49:35 -05:00
2025-01-28 16:03:31 -06:00
2025-02-25 12:09:52 -05:00
2025-01-28 16:03:31 -06:00