nushell/tests/const_
Yash Thakur 90d65bb987
Evaluate string interpolation at parse time (#11562)
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Closes #11561

# Description
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This PR will allow string interpolation at parse time.

Since the actual config hasn't been loaded at parse time, this uses the
`get_config()` method on `StateWorkingSet`. So file sizes and datetimes
(I think those are the only things whose string representations depend
on the config) may be formatted differently from how users have
configured things, which may come as a surprise to some. It does seem
unlikely that anyone would be formatting file sizes or date times at
parse time. Still, something to think about if/before this PR merged.

Also, I changed the `ModuleNotFound` error to include the name of the
module.

# User-Facing Changes
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Users will be able to do stuff like:

```nu
const x = [1 2 3]
const y = $"foo($x)" // foo[1, 2, 3]
```

The main use case is `use`-ing and `source`-ing files at parse time:

```nu
const file = "foo.nu"
use $"($file)"
```

If the module isn't found, you'll see an error like this:
```
Error: nu::parser::module_not_found

  × Module not found.
   ╭─[entry #3:1:1]
 1 │  use $"($file)"
   ·      ─────┬────
   ·           ╰── module foo.nu not found
   ╰────
  help: module files and their paths must be available before your script is run as parsing occurs before anything is evaluated
```

# Tests + Formatting
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# After Submitting
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Although there's user-facing changes, there's probably no need to change
the docs since people probably already expect string interpolation to
work at parse time.

Edit: @kubouch pointed out that we'd need to document the fact that
stuff like file sizes and datetimes won't get formatted according to
user's runtime configs, so I'll make a PR to nushell.github.io after
this one
2024-01-22 09:13:48 +02:00
..
mod.rs Evaluate string interpolation at parse time (#11562) 2024-01-22 09:13:48 +02:00