Implement but describe

krlvi · krlvi · commit 726653e25245 · 2025-09-26T12:06:10.000+02:00
diff --git a/crates/but/src/args.rs b/crates/but/src/args.rs
@@ -78,6 +78,12 @@ For examples see `but rub --help`."
         #[clap(short = 'o', long = "only")]
         only: bool,
     },
+    /// Edit the commit message of the specified commit.
+    #[clap(alias = "desc")]
+    Describe {
+        /// Commit ID to edit the message for
+        commit: String,
+    },
     /// Starts up the MCP server.
     Mcp {
         /// Starts the internal MCP server which has more granular tools.
@@ -115,6 +121,8 @@ pub enum CommandName {
     Rub,
     #[clap(alias = "commit")]
     Commit,
+    #[clap(alias = "describe")]
+    Describe,
     BaseCheck,
     BaseUpdate,
     BranchNew,
diff --git a/crates/but/src/describe/mod.rs b/crates/but/src/describe/mod.rs
@@ -0,0 +1,233 @@
+use crate::id::CliId;
+use anyhow::Result;
+use but_settings::AppSettings;
+use gitbutler_command_context::CommandContext;
+use gitbutler_oxidize::ObjectIdExt;
+use gitbutler_project::Project;
+use std::path::Path;
+
+pub(crate) fn edit_commit_message(
+    repo_path: &Path,
+    _json: bool,
+    commit_target: &str,
+) -> Result<()> {
+    let project = Project::find_by_path(repo_path)?;
+    let mut ctx = CommandContext::open(&project, AppSettings::load_from_default_path_creating()?)?;
+
+    // Resolve the commit ID
+    let cli_ids = CliId::from_str(&mut ctx, commit_target)?;
+
+    if cli_ids.is_empty() {
+        anyhow::bail!("Commit '{}' not found", commit_target);
+    }
+
+    if cli_ids.len() > 1 {
+        anyhow::bail!(
+            "Commit '{}' is ambiguous. Found {} matches",
+            commit_target,
+            cli_ids.len()
+        );
+    }
+
+    let cli_id = &cli_ids[0];
+
+    match cli_id {
+        CliId::Commit { oid } => {
+            edit_commit_message_by_id(&ctx, &project, *oid)?;
+        }
+        _ => {
+            anyhow::bail!("Target must be a commit ID, not {}", cli_id.kind());
+        }
+    }
+
+    Ok(())
+}
+
+fn edit_commit_message_by_id(
+    ctx: &CommandContext,
+    project: &Project,
+    commit_oid: gix::ObjectId,
+) -> Result<()> {
+    // Find which stack this commit belongs to
+    let stacks = but_api::workspace::stacks(project.id, None)?;
+    let mut found_commit_message = None;
+    let mut stack_id = None;
+
+    for stack_entry in &stacks {
+        if let Some(sid) = stack_entry.id {
+            let stack_details = but_api::workspace::stack_details(project.id, Some(sid))?;
+
+            // Check if this commit exists in any branch of this stack
+            for branch_details in &stack_details.branch_details {
+                // Check local commits
+                for commit in &branch_details.commits {
+                    if commit.id == commit_oid {
+                        found_commit_message = Some(commit.message.clone());
+                        stack_id = Some(sid);
+                        break;
+                    }
+                }
+
+                // Also check upstream commits
+                if found_commit_message.is_none() {
+                    for commit in &branch_details.upstream_commits {
+                        if commit.id == commit_oid {
+                            found_commit_message = Some(commit.message.clone());
+                            stack_id = Some(sid);
+                            break;
+                        }
+                    }
+                }
+
+                if found_commit_message.is_some() {
+                    break;
+                }
+            }
+            if found_commit_message.is_some() {
+                break;
+            }
+        }
+    }
+
+    let commit_message = found_commit_message
+        .ok_or_else(|| anyhow::anyhow!("Commit {} not found in any stack", commit_oid))?;
+
+    let stack_id = stack_id
+        .ok_or_else(|| anyhow::anyhow!("Could not find stack for commit {}", commit_oid))?;
+
+    // Get the files changed in this commit using but_api
+    let commit_details = but_api::diff::commit_details(project.id, commit_oid.into())?;
+    let changed_files = get_changed_files_from_commit_details(&commit_details);
+
+    // Get current commit message
+    let current_message = commit_message.to_string();
+
+    // Open editor with current message and file list
+    let new_message = get_commit_message_from_editor(&current_message, &changed_files)?;
+
+    if new_message.trim() == current_message.trim() {
+        println!("No changes to commit message.");
+        return Ok(());
+    }
+
+    // Use gitbutler_branch_actions::update_commit_message instead of low-level primitives
+    let git2_commit_oid = commit_oid.to_git2();
+    let new_commit_oid = gitbutler_branch_actions::update_commit_message(
+        ctx,
+        stack_id,
+        git2_commit_oid,
+        &new_message,
+    )?;
+
+    println!(
+        "Updated commit message for {} (now {})",
+        &commit_oid.to_string()[..7],
+        &new_commit_oid.to_string()[..7]
+    );
+
+    Ok(())
+}
+
+fn get_changed_files_from_commit_details(
+    commit_details: &but_api::diff::CommitDetails,
+) -> Vec<String> {
+    let mut files = Vec::new();
+
+    for change in &commit_details.changes.changes {
+        let status = match &change.status {
+            but_core::ui::TreeStatus::Addition { .. } => "new file:",
+            but_core::ui::TreeStatus::Deletion { .. } => "deleted:",
+            but_core::ui::TreeStatus::Modification { .. } => "modified:",
+            but_core::ui::TreeStatus::Rename { .. } => "modified:",
+        };
+
+        let file_path = change.path.to_string();
+        files.push(format!("{status}   {file_path}"));
+    }
+
+    files.sort();
+    files
+}
+
+fn get_commit_message_from_editor(
+    current_message: &str,
+    changed_files: &[String],
+) -> Result<String> {
+    // Get editor command
+    let editor = get_editor_command()?;
+
+    // Create temporary file with current message and file list
+    let temp_dir = std::env::temp_dir();
+    let temp_file = temp_dir.join(format!("but_commit_msg_{}", std::process::id()));
+
+    // Generate commit message template with current message
+    let mut template = String::new();
+    template.push_str(current_message);
+    if !current_message.is_empty() && !current_message.ends_with('\n') {
+        template.push('\n');
+    }
+    template.push_str("\n# Please enter the commit message for your changes. Lines starting\n");
+    template.push_str("# with '#' will be ignored, and an empty message aborts the commit.\n");
+    template.push_str("#\n");
+    template.push_str("# Changes in this commit:\n");
+
+    for file in changed_files {
+        template.push_str(&format!("#\t{file}\n"));
+    }
+    template.push_str("#\n");
+
+    std::fs::write(&temp_file, template)?;
+
+    // Launch editor
+    let status = std::process::Command::new(&editor)
+        .arg(&temp_file)
+        .status()?;
+
+    if !status.success() {
+        anyhow::bail!("Editor exited with non-zero status");
+    }
+
+    // Read the result and strip comments
+    let content = std::fs::read_to_string(&temp_file)?;
+    std::fs::remove_file(&temp_file).ok(); // Best effort cleanup
+
+    let message = content
+        .lines()
+        .filter(|line| !line.starts_with('#'))
+        .collect::<Vec<_>>()
+        .join("\n")
+        .trim()
+        .to_string();
+
+    if message.is_empty() {
+        anyhow::bail!("Aborting due to empty commit message");
+    }
+
+    Ok(message)
+}
+
+fn get_editor_command() -> Result<String> {
+    // Try $EDITOR first
+    if let Ok(editor) = std::env::var("EDITOR") {
+        return Ok(editor);
+    }
+
+    // Try git config core.editor
+    if let Ok(output) = std::process::Command::new("git")
+        .args(["config", "--get", "core.editor"])
+        .output()
+        && output.status.success()
+    {
+        let editor = String::from_utf8_lossy(&output.stdout).trim().to_string();
+        if !editor.is_empty() {
+            return Ok(editor);
+        }
+    }
+
+    // Fallback to platform defaults
+    #[cfg(windows)]
+    return Ok("notepad".to_string());
+
+    #[cfg(not(windows))]
+    return Ok("vi".to_string());
+}
diff --git a/crates/but/src/main.rs b/crates/but/src/main.rs
@@ -10,6 +10,7 @@ mod base;
 mod branch;
 mod command;
 mod commit;
+mod describe;
 mod id;
 mod init;
 mod log;
@@ -166,6 +167,11 @@ async fn main() -> Result<()> {
             metrics_if_configured(app_settings, CommandName::Commit, props(start, &result)).ok();
             result
         }
+        Subcommands::Describe { commit } => {
+            let result = describe::edit_commit_message(&args.current_dir, args.json, commit);
+            metrics_if_configured(app_settings, CommandName::Describe, props(start, &result)).ok();
+            result
+        }
         Subcommands::Init { repo } => init::repo(&args.current_dir, args.json, *repo)
             .context("Failed to initialize GitButler project."),
     }
