nushell/crates
Yash Thakur 87717b9ddd
Don't redraw prompt when transient prompt disabled (#10788)
# Description
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moonlander pointed out in Discord that the transient prompt feature
added in release 0.86 (implemented in #10391) is causing the normal
prompt to be redrawn when the transient prompt variables are unset or
set to null. This PR is for fixing that, although it's more of a bandaid
fix. Maybe the transient prompt feature should be taken out entirely for
now so more thought can be given to its implementation.

Previously, I'd thought that when reedline redraws the prompt after a
command is entered, it's a whole new prompt, but apparently it's
actually the same prompt as the current line (?). So now, `nu_prompt` in
`repl.rs` is an `Arc<RwLock<NushellPrompt>>` (rather than just a
`NushellPrompt`), and this `Arc` is shared with the `TransientPrompt`
object so that if it can't find one of the `TRANSIENT_PROMPT_*`
variables, it uses a segment from `NushellPrompt` rather than
re-evaluate `PROMPT_COMMAND`, `PROMPT_COMMAND_RIGHT`, etc. Using an
`RwLock` means that there's a bunch of `.expect()`s all over the place,
which is not nice. It could perhaps be avoided with some changes on the
reedline side.

# User-Facing Changes
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`$env.PROMPT_COMMAND` (and other such variables) should no longer be
executed twice if the corresponding `$env.TRANSIENT_PROMPT_*` variable
is not set.

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# Steps to reproduce

Described by moonlander in Discord
[here](https://discord.com/channels/601130461678272522/614593951969574961/1164928022126792844).

Adding this to `env.nu` will result in `11` being added to
`/tmp/run_count` every time any command is run. The expected behavior is
a single `1` being added to `/tmp/run_count` instead of two. The prompt
command should not be executed again when the prompt is redrawn after a
command is executed.

```nu
$env.PROMPT_COMMAND = {||
  touch /tmp/run_count
  '1' | save /tmp/run_count --append
  '>'
}

# $env.TRANSIENT_PROMPT_COMMAND not set
```

If the following is added to `env.nu`, then `12` will be added to
`/tmp/run_count` every time any command is run, which is expected
behavior because the normal prompt command must be displayed the first
time the prompt is shown, then the transient prompt command is run when
the prompt is redrawn.
```nu
$env.TRANSIENT_PROMPT_COMMAND = {||
  touch /tmp/run_count
  '2' | save /tmp/run_count --append
  '>'
}
```

Here's a screenshot of what adding that first snippet looks like (`cargo
run` in the `main` branch):

![image](https://github.com/nushell/nushell/assets/45539777/b27a5c07-55b4-43c7-8a2c-0deba2d9d53a)


Here's a screenshot of what it looks like with this PR (only one `1` is
added to `/tmp/run_count` each time):

![image](https://github.com/nushell/nushell/assets/45539777/2b5c0a3a-8566-4428-9fda-1ffcc1dd6ae3)
2023-12-15 13:41:44 -06:00
..
nu-cli Don't redraw prompt when transient prompt disabled (#10788) 2023-12-15 13:41:44 -06:00
nu-cmd-base Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
nu-cmd-dataframe Polars Struct support without unsafe blocks (#11229) 2023-12-15 11:21:30 +01:00
nu-cmd-extra Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
nu-cmd-lang Enforce required, optional, and rest positional arguments start with an uppercase and end with a period. (#11285) 2023-12-15 14:32:37 +08:00
nu-color-config Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
nu-command Add ulimit command (#11324) 2023-12-15 07:11:17 -06:00
nu-engine Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
nu-explore Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
nu-glob Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
nu-json Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
nu-lsp Make hover equal to help command (#11320) 2023-12-15 11:39:19 -06:00
nu-parser disable directory submodule auto export (#11157) 2023-12-15 12:37:55 +01:00
nu-path Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
nu-plugin Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
nu-pretty-hex Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
nu-protocol Move history into their own module (#11308) 2023-12-15 13:17:12 +01:00
nu-std disable directory submodule auto export (#11157) 2023-12-15 12:37:55 +01:00
nu-system Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
nu-table Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
nu-term-grid Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
nu-test-support Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
nu-utils Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
nu_plugin_custom_values Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
nu_plugin_example Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
nu_plugin_formats Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
nu_plugin_gstat Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
nu_plugin_inc Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
nu_plugin_python remove vectorize_over_list from python plugin (#9905) 2023-08-03 16:46:48 +02:00
nu_plugin_query Bump version to 0.88.2 (#11333) 2023-12-14 13:55:48 -06:00
README.md Remove old nushell/merge engine-q 2022-02-07 14:54:06 -05:00

Nushell core libraries and plugins

These sub-crates form both the foundation for Nu and a set of plugins which extend Nu with additional functionality.

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