feat(hostname): add option to replace hostnames with aliases (#6097)

---------

Co-authored-by: David Knaack <davidkna@users.noreply.github.com>

.github/config-schema.json

@@ -842,6 +842,7 @@
     },
     "hostname": {
       "default": {
+        "aliases": {},
         "detect_env_vars": [],
         "disabled": false,
         "format": "[$ssh_symbol$hostname]($style) in ",
@@ -4008,6 +4009,13 @@
         "disabled": {
           "default": false,
           "type": "boolean"
+        },
+        "aliases": {
+          "default": {},
+          "type": "object",
+          "additionalProperties": {
+            "type": "string"
+          }
         }
       },
       "additionalProperties": false

docs/config/README.md

@@ -2355,6 +2355,7 @@ The `hostname` module shows the system hostname.
 | `format`          | `'[$ssh_symbol$hostname]($style) in '` | The format for the module.                                                                                                            |
 | `style`           | `'bold dimmed green'`                  | The style for the module.                                                                                                             |
 | `disabled`        | `false`                                | Disables the `hostname` module.                                                                                                       |
+| `aliases`         | `{}`                                   | Translate system hostnames to something else. If `trim_at` is specified, only the first part will be matched and replaced.            |
 
 ### Variables
 
@@ -2391,6 +2392,14 @@ detect_env_vars = ['!TMUX', 'SSH_CONNECTION']
 disabled = false
 ```
 
+#### Replace the hostname with a nickname
+
+```toml
+# ~/.config/starship.toml
+[hostname]
+aliases = { "Max's MacBook Pro" = "home" }
+```
+
 ## Java
 
 The `java` module shows the currently installed version of [Java](https://www.oracle.com/java/).
@@ -4539,7 +4548,7 @@ these variables, one workaround is to set one of them with a dummy value.
 | `format`          | `'[$user]($style) in '` | The format for the module.                                |
 | `show_always`     | `false`                 | Always shows the `username` module.                       |
 | `disabled`        | `false`                 | Disables the `username` module.                           |
-| `aliases`         | `{}`                    | Translate system usernames to something else              |
+| `aliases`         | `{}`                    | Translate system usernames to something else.             |
 
 ### Variables
 

src/configs/hostname.rs

@@ -1,3 +1,4 @@
+use indexmap::IndexMap;
 use serde::{Deserialize, Serialize};
 
 #[derive(Clone, Deserialize, Serialize)]
@@ -15,6 +16,7 @@ pub struct HostnameConfig<'a> {
     pub format: &'a str,
     pub style: &'a str,
     pub disabled: bool,
+    pub aliases: IndexMap<String, &'a str>,
 }
 
 impl<'a> Default for HostnameConfig<'a> {
@@ -27,6 +29,7 @@ impl<'a> Default for HostnameConfig<'a> {
             format: "[$ssh_symbol$hostname]($style) in ",
             style: "green dimmed bold",
             disabled: false,
+            aliases: IndexMap::new(),
         }
     }
 }

src/modules/hostname.rs

@@ -35,7 +35,7 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
 
     //rustc doesn't let you do an "if" and an "if let" in the same if statement
     // if this changes in the future this can become a lot cleaner
-    let host = if !config.trim_at.is_empty() {
+    let mut host = if !config.trim_at.is_empty() {
         if let Some(index) = host.find(config.trim_at) {
             host.split_at(index).0
         } else {
@@ -45,6 +45,10 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         host.as_ref()
     };
 
+    if let Some(&alias) = config.aliases.get(host) {
+        host = alias;
+    }
+
     let parsed = StringFormatter::new(config.format).and_then(|formatter| {
         formatter
             .map_meta(|var, _| match var {
@@ -259,6 +263,61 @@ mod tests {
         assert_eq!(expected, actual);
     }
 
+    #[test]
+    fn test_alias() {
+        let hostname = get_hostname!();
+        let mut toml_config = toml::toml!(
+            [hostname]
+            ssh_only = false
+            trim_at = ""
+            aliases = {}
+        );
+        toml_config["hostname"]["aliases"]
+            .as_table_mut()
+            .unwrap()
+            .insert(
+                hostname.clone(),
+                toml::Value::String("homeworld".to_string()),
+            );
+        let actual = ModuleRenderer::new("hostname")
+            .config(toml_config)
+            .collect();
+
+        let expected = Some(format!("{} in ", style().paint("homeworld")));
+        assert_eq!(expected, actual);
+    }
+
+    #[test]
+    fn test_alias_with_trim_at() {
+        let hostname = get_hostname!();
+
+        let mut hostname_iter = hostname.graphemes(true);
+        let remainder = hostname_iter.next().unwrap_or_default();
+        let trim_at = hostname_iter.collect::<String>();
+
+        // Trimmed hostname needs to be non-empty
+        if remainder.is_empty() {
+            log::warn!("Skipping test_alias_with_trim_at because hostname is too short");
+            return;
+        }
+        let mut toml_config = toml::toml!(
+            [hostname]
+            ssh_only = false
+            trim_at = trim_at
+            aliases = {}
+        );
+        toml_config["hostname"]["aliases"]
+            .as_table_mut()
+            .unwrap()
+            .insert(remainder.to_string(), toml::Value::String("🌍".to_string()));
+        let actual = ModuleRenderer::new("hostname")
+            .config(toml_config)
+            .collect();
+
+        let expected = Some(format!("{} in ", style().paint("🌍")));
+        assert_eq!(expected, actual);
+    }
+
     fn style() -> Style {
         Color::Green.bold().dimmed()
     }