feat: add support for git branchless --show-signature

Author: Abhijay

git-branchless-lib/src/core/node_descriptors.rs

@@ -516,6 +516,79 @@ impl NodeDescriptor for RelativeTimeDescriptor {
     }
 }
 
+/// Display the GPG signature status for a commit.
+#[derive(Debug)]
+pub struct SignatureStatusDescriptor {
+    is_enabled: bool,
+    repo_path: String,
+}
+
+impl SignatureStatusDescriptor {
+    /// Constructor.
+    pub fn new(repo: &Repo, is_enabled: bool) -> eyre::Result<Self> {
+        let repo_path = repo.get_path().to_string_lossy().to_string();
+        Ok(Self {
+            is_enabled,
+            repo_path,
+        })
+    }
+}
+
+impl NodeDescriptor for SignatureStatusDescriptor {
+    #[instrument]
+    fn describe_node(
+        &mut self,
+        _glyphs: &Glyphs,
+        object: &NodeObject,
+    ) -> eyre::Result<Option<StyledString>> {
+        if !self.is_enabled {
+            return Ok(None);
+        }
+
+        let oid = object.get_oid().to_string();
+
+        // Use git command-line to get signature information as git2 doesn't
+        // expose GPG signature verification directly
+        let output = std::process::Command::new("git")
+            .args(["-C", &self.repo_path, "verify-commit", &oid, "--raw"])
+            .output();
+
+        match output {
+            Ok(output) => {
+                if output.status.success() {
+                    // Good signature
+                    let mut result = StyledString::new();
+                    result.append_styled("[G]", BaseColor::Green.light());
+                    Ok(Some(result))
+                } else {
+                    // Bad signature
+                    let stderr = String::from_utf8_lossy(&output.stderr);
+                    if stderr.contains("BAD signature") {
+                        let mut result = StyledString::new();
+                        result.append_styled("[B]", BaseColor::Red.light());
+                        Ok(Some(result))
+                    } else if stderr.contains("No signature") {
+                        let mut result = StyledString::new();
+                        result.append_styled("[N]", BaseColor::Yellow.light());
+                        Ok(Some(result))
+                    } else {
+                        // Unknown error
+                        let mut result = StyledString::new();
+                        result.append_styled("[?]", BaseColor::Magenta.light());
+                        Ok(Some(result))
+                    }
+                }
+            }
+            Err(_) => {
+                // Error running command
+                let mut result = StyledString::new();
+                result.append_styled("[E]", BaseColor::Red.light());
+                Ok(Some(result))
+            }
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use std::ops::{Add, Sub};

git-branchless-opts/src/lib.rs

@@ -406,6 +406,10 @@ pub struct SmartlogArgs {
     /// Options for resolving revset expressions.
     #[clap(flatten)]
     pub resolve_revset_options: ResolveRevsetOptions,
+
+    /// Show GPG signature status for each commit.
+    #[clap(action, long = "show-signature")]
+    pub show_signature: bool,
 }
 
 /// The Git hosting provider to use, called a "forge".

git-branchless-smartlog/src/lib.rs

@@ -34,7 +34,7 @@ use lib::core::formatting::Pluralize;
 use lib::core::node_descriptors::{
     BranchesDescriptor, CommitMessageDescriptor, CommitOidDescriptor,
     DifferentialRevisionDescriptor, ObsolescenceExplanationDescriptor, Redactor,
-    RelativeTimeDescriptor,
+    RelativeTimeDescriptor, SignatureStatusDescriptor,
 };
 use lib::git::{GitRunInfo, Repo};
 
@@ -753,6 +753,9 @@ mod render {
 
         /// Normally HEAD and the main branch are included. Set this to exclude them.
         pub exact: bool,
+
+        /// Show GPG signature status for each commit.
+        pub show_signature: bool,
     }
 }
 
@@ -769,6 +772,7 @@ pub fn smartlog(
         resolve_revset_options,
         reverse,
         exact,
+        show_signature,
     } = options;
 
     let repo = Repo::from_dir(&git_run_info.working_directory)?;
@@ -845,6 +849,7 @@ pub fn smartlog(
                 &Redactor::Disabled,
             )?,
             &mut DifferentialRevisionDescriptor::new(&repo, &Redactor::Disabled)?,
+            &mut SignatureStatusDescriptor::new(&repo, show_signature)?,
             &mut CommitMessageDescriptor::new(&Redactor::Disabled)?,
         ],
     )?
@@ -916,6 +921,7 @@ pub fn command_main(ctx: CommandContext, args: SmartlogArgs) -> EyreExitOr<()> {
         resolve_revset_options,
         reverse,
         exact,
+        show_signature,
     } = args;
 
     smartlog(
@@ -927,6 +933,7 @@ pub fn command_main(ctx: CommandContext, args: SmartlogArgs) -> EyreExitOr<()> {
             resolve_revset_options,
             reverse,
             exact,
+            show_signature,
         },
     )
 }