feat(nix_shell): add symbol to nix-shell module (#1058)

* feat: add nix-shell icon

Fixes #1048

* style: make nix-shell bold blue by default

It better matches the whole theme around Nix and snowflakes.

docs/config/README.md

@@ -978,11 +978,12 @@ The module will be shown when inside a nix-shell environment.
 ### Options
 
 | Variable     | Default       | Description                                       |
-| ------------ | ------------ | ---------------------------------- |
+| ------------ | ------------- | ------------------------------------------------- |
 | `use_name`   | `false`       | Display the name of the nix-shell.                |
 | `impure_msg` | `"impure"`    | Customize the "impure" msg.                       |
 | `pure_msg`   | `"pure"`      | Customize the "pure" msg.                         |
-| `style`      | `"bold red"` | The style for the module.          |
+| `symbol`     | `"❄️  "`       | The symbol used before displaying the shell name. |
+| `style`      | `"bold blue"` | The style for the module.                         |
 | `disabled`   | `false`       | Disables the `nix_shell` module.                  |
 
 ### Example
@@ -995,6 +996,7 @@ disabled = true
 use_name = true
 impure_msg = "impure shell"
 pure_msg = "pure shell"
+symbol = "☃️  "
 ```
 
 ## NodeJS

src/configs/nix_shell.rs

@@ -9,6 +9,7 @@ pub struct NixShellConfig<'a> {
     pub impure_msg: SegmentConfig<'a>,
     pub pure_msg: SegmentConfig<'a>,
     pub style: Style,
+    pub symbol: SegmentConfig<'a>,
     pub disabled: bool,
 }
 
@@ -18,7 +19,8 @@ impl<'a> RootModuleConfig<'a> for NixShellConfig<'a> {
             use_name: false,
             impure_msg: SegmentConfig::new("impure"),
             pure_msg: SegmentConfig::new("pure"),
-            style: Color::Red.bold(),
+            style: Color::Blue.bold(),
+            symbol: SegmentConfig::new("❄️  "),
             disabled: false,
         }
     }

src/modules/nix_shell.rs

@@ -27,6 +27,7 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     let config: NixShellConfig = NixShellConfig::try_load(module.config);
 
     module.set_style(config.style);
+    module.create_segment("symbol", &config.symbol);
 
     let shell_type = env::var("IN_NIX_SHELL").ok()?;
     let shell_type_segment: SegmentConfig = match shell_type.as_ref() {

tests/testsuite/nix_shell.rs

@@ -28,7 +28,7 @@ fn pure_shell() -> io::Result<()> {
         .output()?;
     let actual = String::from_utf8(output.stdout).unwrap();
 
-    let expected = format!("via {} ", Color::Red.bold().paint("pure"));
+    let expected = format!("via {} ", Color::Blue.bold().paint("❄️  pure"));
     assert_eq!(expected, actual);
     Ok(())
 }
@@ -40,7 +40,7 @@ fn impure_shell() -> io::Result<()> {
         .output()?;
     let actual = String::from_utf8(output.stdout).unwrap();
 
-    let expected = format!("via {} ", Color::Red.bold().paint("impure"));
+    let expected = format!("via {} ", Color::Blue.bold().paint("❄️  impure"));
     assert_eq!(expected, actual);
     Ok(())
 }
@@ -52,7 +52,7 @@ fn lorri_shell() -> io::Result<()> {
         .output()?;
     let actual = String::from_utf8(output.stdout).unwrap();
 
-    let expected = format!("via {} ", Color::Red.bold().paint("impure"));
+    let expected = format!("via {} ", Color::Blue.bold().paint("❄️  impure"));
     assert_eq!(expected, actual);
     Ok(())
 }