feat: Add git_commit module (#673)

10 files changed, 205 insertions, 0 deletions

diff --git a/docs/config/README.md b/docs/config/README.md
index 9b2973235..b9a766099 100644
--- a/docs/config/README.md
+++ b/docs/config/README.md
@@ -91,6 +91,7 @@ prompt_order = [
     "kubernetes",
     "directory",
     "git_branch",
+    "git_commit",
     "git_state",
     "git_status",
     "hg_branch",
@@ -438,6 +439,38 @@ truncation_length = 4
 truncation_symbol = ""
 ```
 
+
+## Git Commit
+
+The `git_commit` module shows the active branch of the repo in your current directory.
+
+::: tip
+
+This module is disabled by default.
+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.     |
+| `style`               | `"green"` | The style for the module.                        |
+| `prefix`              | `(`       | Prefix to display immediately before git commit. |
+| `suffix`              | `)`       | Suffix to display immediately after git commit.  |
+| `disabled`            | `true`    | Disables the `git_commit` module.                |
+
+### Example
+
+```toml
+# ~/.config/starship.toml
+
+[git_commit]
+disabled = false
+commit_hash_length = 4
+```
+
 ## Git State
 
 The `git_state` module will show in directories which are part of a git
diff --git a/src/config.rs b/src/config.rs
index 027ca75ac..c2c8c0a45 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -98,6 +98,22 @@ impl<'a> ModuleConfig<'a> for f64 {
     }
 }
 
+impl<'a> ModuleConfig<'a> for usize {
+    fn from_config(config: &Value) -> Option<Self> {
+        match config {
+            Value::Integer(value) => {
+                if *value > 0 {
+                    Some(*value as usize)
+                } else {
+                    None
+                }
+            }
+            Value::String(value) => value.parse::<usize>().ok(),
+            _ => None,
+        }
+    }
+}
+
 impl<'a, T> ModuleConfig<'a> for Vec<T>
 where
     T: ModuleConfig<'a>,
diff --git a/src/configs/git_commit.rs b/src/configs/git_commit.rs
new file mode 100644
index 000000000..d6f65fdcb
--- /dev/null
+++ b/src/configs/git_commit.rs
@@ -0,0 +1,28 @@
+use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+
+use ansi_term::{Color, Style};
+use starship_module_config_derive::ModuleConfig;
+
+#[derive(Clone, ModuleConfig)]
+pub struct GitCommitConfig<'a> {
+    pub commit_hash_length: usize,
+    pub hash: SegmentConfig<'a>,
+    pub prefix: &'a str,
+    pub suffix: &'a str,
+    pub style: Style,
+    pub disabled: bool,
+}
+
+impl<'a> RootModuleConfig<'a> for GitCommitConfig<'a> {
+    fn new() -> Self {
+        GitCommitConfig {
+            // be consistent with git by default, which has DEFAULT_ABBREV set to 7
+            commit_hash_length: 7,
+            hash: SegmentConfig::default(),
+            prefix: "(",
+            suffix: ") ",
+            style: Color::Green.bold(),
+            disabled: true,
+        }
+    }
+}
diff --git a/src/configs/mod.rs b/src/configs/mod.rs
index 553307895..c840f3bba 100644
--- a/src/configs/mod.rs
+++ b/src/configs/mod.rs
@@ -7,6 +7,7 @@ pub mod directory;
 pub mod dotnet;
 pub mod env_var;
 pub mod git_branch;
+pub mod git_commit;
 pub mod git_state;
 pub mod git_status;
 pub mod go;
diff --git a/src/configs/starship_root.rs b/src/configs/starship_root.rs
index eb0523a29..293dcb17c 100644
--- a/src/configs/starship_root.rs
+++ b/src/configs/starship_root.rs
@@ -22,6 +22,7 @@ impl<'a> RootModuleConfig<'a> for StarshipRootConfig<'a> {
                 "kubernetes",
                 "directory",
                 "git_branch",
+                "git_commit",
                 "git_state",
                 "git_status",
                 "hg_branch",
diff --git a/src/module.rs b/src/module.rs
index 591934f29..71b25627f 100644
--- a/src/module.rs
+++ b/src/module.rs
@@ -18,6 +18,7 @@ pub const ALL_MODULES: &[&str] = &[
     "dotnet",
     "env_var",
     "git_branch",
+    "git_commit",
     "git_state",
     "git_status",
     "golang",
diff --git a/src/modules/git_commit.rs b/src/modules/git_commit.rs
new file mode 100644
index 000000000..cacfa3982
--- /dev/null
+++ b/src/modules/git_commit.rs
@@ -0,0 +1,54 @@
+use super::{Context, Module, RootModuleConfig};
+use git2::Repository;
+
+use crate::configs::git_commit::GitCommitConfig;
+
+/// Creates a module with the Git commit in the current directory
+///
+/// Will display the commit hash if the current directory is a git repo
+pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
+    let mut module = context.new_module("git_commit");
+    let config = GitCommitConfig::try_load(module.config);
+    if config.disabled {
+        return None;
+    };
+
+    module
+        .get_prefix()
+        .set_value(config.prefix)
+        .set_style(config.style);
+    module
+        .get_suffix()
+        .set_value(config.suffix)
+        .set_style(config.style);
+    module.set_style(config.style);
+
+    let repo = context.get_repo().ok()?;
+    let repo_root = repo.root.as_ref()?;
+    let git_repo = Repository::open(repo_root).ok()?;
+
+    let git_head = git_repo.head().ok()?;
+    let head_commit = git_head.peel_to_commit().ok()?;
+    let commit_oid = head_commit.id();
+    module.create_segment(
+        "hash",
+        &config.hash.with_value(&id_to_hex_abbrev(
+            commit_oid.as_bytes(),
+            config.commit_hash_length,
+        )),
+    );
+
+    Some(module)
+}
+
+/// len specifies length of hex encoded string
+pub fn id_to_hex_abbrev(bytes: &[u8], len: usize) -> String {
+    bytes
+        .iter()
+        .map(|b| format!("{:02x}", b))
+        .collect::<Vec<String>>()
+        .join("")
+        .chars()
+        .take(len)
+        .collect()
+}
diff --git a/src/modules/mod.rs b/src/modules/mod.rs
index f69c94653..42951324b 100644
--- a/src/modules/mod.rs
+++ b/src/modules/mod.rs
@@ -7,6 +7,7 @@ mod directory;
 mod dotnet;
 mod env_var;
 mod git_branch;
+mod git_commit;
 mod git_state;
 mod git_status;
 mod golang;
@@ -49,6 +50,7 @@ pub fn handle<'a>(module: &str, context: &'a Context) -> Option<Module<'a>> {
         "dotnet" => dotnet::module(context),
         "env_var" => env_var::module(context),
         "git_branch" => git_branch::module(context),
+        "git_commit" => git_commit::module(context),
         "git_state" => git_state::module(context),
         "git_status" => git_status::module(context),
         "golang" => golang::module(context),
diff --git a/tests/testsuite/git_commit.rs b/tests/testsuite/git_commit.rs
new file mode 100644
index 000000000..c7dd50bbe
--- /dev/null
+++ b/tests/testsuite/git_commit.rs
@@ -0,0 +1,68 @@
+use ansi_term::Color;
+use std::process::Command;
+use std::{io, str};
+
+use crate::common::{self, TestCommand};
+
+#[test]
+fn test_render_commit_hash() -> io::Result<()> {
+    let repo_dir = common::create_fixture_repo()?;
+
+    let mut git_output = Command::new("git")
+        .args(&["rev-parse", "HEAD"])
+        .current_dir(repo_dir.as_path())
+        .output()?
+        .stdout;
+    git_output.truncate(7);
+    let expected_hash = str::from_utf8(&git_output).unwrap();
+
+    let output = common::render_module("git_commit")
+        .use_config(toml::toml! {
+            [git_commit]
+                disabled = false
+        })
+        .arg("--path")
+        .arg(repo_dir)
+        .output()?;
+
+    let actual = String::from_utf8(output.stdout).unwrap();
+    let expected = Color::Green
+        .bold()
+        .paint(format!("({}) ", expected_hash))
+        .to_string();
+
+    assert_eq!(expected, actual);
+    Ok(())
+}
+
+#[test]
+fn test_render_commit_hash_len_override() -> io::Result<()> {
+    let repo_dir = common::create_fixture_repo()?;
+
+    let mut git_output = Command::new("git")
+        .args(&["rev-parse", "HEAD"])
+        .current_dir(repo_dir.as_path())
+        .output()?
+        .stdout;
+    git_output.truncate(14);
+    let expected_hash = str::from_utf8(&git_output).unwrap();
+
+    let output = common::render_module("git_commit")
+        .use_config(toml::toml! {
+            [git_commit]
+                disabled = false
+                commit_hash_length = 14
+        })
+        .arg("--path")
+        .arg(repo_dir)
+        .output()?;
+
+    let actual = String::from_utf8(output.stdout).unwrap();
+    let expected = Color::Green
+        .bold()
+        .paint(format!("({}) ", expected_hash))
+        .to_string();
+
+    assert_eq!(expected, actual);
+    Ok(())
+}
diff --git a/tests/testsuite/main.rs b/tests/testsuite/main.rs
index c3e209262..214f8b013 100644
--- a/tests/testsuite/main.rs
+++ b/tests/testsuite/main.rs
@@ -8,6 +8,7 @@ mod directory;
 mod dotnet;
 mod env_var;
 mod git_branch;
+mod git_commit;
 mod git_state;
 mod git_status;
 mod golang;