feat: Add only_detached option to git_commit module (#706)

docs/config/README.md

@@ -461,13 +461,14 @@ To enable it, set `disabled` to `false` in your configuration file.
 
 ### Options
 
-| Variable             | Default        | Description                                      |
-| -------------------- | -------------- | ------------------------------------------------ |
-| `commit_hash_length` | `7`            | The length of the displayed git commit hash.     |
-| `prefix`             | `"("`          | Prefix to display immediately before git commit. |
-| `suffix`             | `")"`          | Suffix to display immediately after git commit.  |
-| `style`              | `"bold green"` | The style for the module.                        |
-| `disabled`           | `true`         | Disables the `git_commit` module.                |
+| Variable             | Default        | Description                                           |
+| -------------------- | -------------- | ----------------------------------------------------- |
+| `commit_hash_length` | `7`            | The length of the displayed git commit hash.          |
+| `prefix`             | `"("`          | Prefix to display immediately before git commit.      |
+| `suffix`             | `")"`          | Suffix to display immediately after git commit.       |
+| `style`              | `"bold green"` | The style for the module.                             |
+| `only_detached`      | `false`        | Only show git commit hash when in detached HEAD state |
+| `disabled`           | `true`         | Disables the `git_commit` module.                     |
 
 ### Example
 

src/configs/git_commit.rs

@@ -10,6 +10,7 @@ pub struct GitCommitConfig<'a> {
     pub prefix: &'a str,
     pub suffix: &'a str,
     pub style: Style,
+    pub only_detached: bool,
     pub disabled: bool,
 }
 
@@ -22,6 +23,7 @@ impl<'a> RootModuleConfig<'a> for GitCommitConfig<'a> {
             prefix: "(",
             suffix: ") ",
             style: Color::Green.bold(),
+            only_detached: false,
             disabled: true,
         }
     }

src/modules/git_commit.rs

@@ -27,6 +27,11 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     let repo_root = repo.root.as_ref()?;
     let git_repo = Repository::open(repo_root).ok()?;
 
+    let is_detached = git_repo.head_detached().ok()?;
+    if config.only_detached && !is_detached {
+        return None;
+    };
+
     let git_head = git_repo.head().ok()?;
     let head_commit = git_head.peel_to_commit().ok()?;
     let commit_oid = head_commit.id();

tests/testsuite/git_commit.rs

@@ -66,3 +66,27 @@ fn test_render_commit_hash_len_override() -> io::Result<()> {
     assert_eq!(expected, actual);
     Ok(())
 }
+
+#[test]
+fn test_render_commit_hash_only_detached() -> io::Result<()> {
+    let repo_dir = common::create_fixture_repo()?;
+
+    Command::new("git")
+        .args(&["checkout", "@~1"])
+        .current_dir(repo_dir.as_path());
+
+    let output = common::render_module("git_commit")
+        .use_config(toml::toml! {
+            [git_commit]
+                disabled = false
+                only_detached = true
+        })
+        .arg("--path")
+        .arg(repo_dir)
+        .output()?;
+
+    let actual = String::from_utf8(output.stdout).unwrap();
+
+    assert_eq!("", actual);
+    Ok(())
+}