Add flag to create squash commits

Documentation/git-absorb.adoc

@@ -66,6 +66,14 @@ FLAGS
         Skip all safety checks as if all --force-* flags were given.
         See those flags to understand the full effect of supplying --force.
 
+-s::
+--squash::
+        Create squash commits instead of fixup commits.
+        +
+        When this flag is used, "fixup commit" may be read as "squash commit"
+        throughout the documentation. All configuration relating to fixup
+        commits will apply to the squash commits instead.
+
 -w::
 --whole-file::
         Match the first commit touching the same file as the current hunk.
@@ -98,7 +106,7 @@ OPTIONS
         Generate completions
         [possible values: bash, fish, nushell, zsh, powershell, elvish]
 
--- <REBASE_OPTIONS>::
+\-- <REBASE_OPTIONS>::
         Options to pass to git rebase after generating commits.
         Must be the last arguments and the `--` must be present.
         Only valid when `--and-rebase` is used.
@@ -212,6 +220,22 @@ edit your local or global `.gitconfig` and add the following section:
     forceDetach = true
 .............................................................................
 
+GENERATE SQUASH COMMITS INSTEAD OF FIXUPS
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+By default, git-absorb will generate fixup commits.
+To instead generate squash commits, edit your local or global `.gitconfig`
+and add the following section:
+
+.............................................................................
+[absorb]
+    createSquashCommits = true
+.............................................................................
+
+When this option is set, "fixup commit" may be read as "squash commit"
+throughout the documentation. All configuration relating to fixup
+commits will apply to the squash commits instead.
+
 GITHUB PROJECT
 --------------
 

src/config.rs

@@ -19,6 +19,9 @@ pub const AUTO_STAGE_IF_NOTHING_STAGED_DEFAULT: bool = false;
 pub const FIXUP_TARGET_ALWAYS_SHA_CONFIG_NAME: &str = "absorb.fixupTargetAlwaysSHA";
 pub const FIXUP_TARGET_ALWAYS_SHA_DEFAULT: bool = false;
 
+pub const CREATE_SQUASH_COMMITS_CONFIG_NAME: &str = "absorb.createSquashCommits";
+pub const CREATE_SQUASH_COMMITS_DEFAULT: bool = false;
+
 pub fn unify<'config>(config: &'config Config, repo: &Repository) -> Config<'config> {
     Config {
         // here, we default to the git config value,
@@ -36,6 +39,12 @@ pub fn unify<'config>(config: &'config Config, repo: &Repository) -> Config<'con
                 ONE_FIXUP_PER_COMMIT_CONFIG_NAME,
                 ONE_FIXUP_PER_COMMIT_DEFAULT,
             ),
+        squash: config.squash
+            || bool_value(
+                repo,
+                CREATE_SQUASH_COMMITS_CONFIG_NAME,
+                CREATE_SQUASH_COMMITS_DEFAULT,
+            ),
         force_author: config.force_author
             || bool_value(repo, FORCE_AUTHOR_CONFIG_NAME, FORCE_AUTHOR_DEFAULT),
         force_detach: config.force_detach

src/lib.rs

@@ -19,6 +19,7 @@ pub struct Config<'a> {
     pub rebase_options: &'a Vec<&'a str>,
     pub whole_file: bool,
     pub one_fixup_per_commit: bool,
+    pub squash: bool,
     pub message: Option<&'a str>,
 }
 
@@ -321,7 +322,8 @@ fn run_with_repo(logger: &slog::Logger, config: &Config, repo: &git2::Repository
                 .stats()?;
             if !config.dry_run {
                 head_tree = new_head_tree;
-                let mut message = format!("fixup! {}\n", dest_commit_locator);
+                let verb = if config.squash { "squash" } else { "fixup" };
+                let mut message = format!("{}! {}\n", verb, dest_commit_locator);
                 if let Some(m) = config.message.filter(|m| !m.is_empty()) {
                     message.push('\n');
                     message.push_str(m);
@@ -718,6 +720,15 @@ mod tests {
         let pre_absorb_ref_commit = ctx.repo.refname_to_id("PRE_ABSORB_HEAD").unwrap();
         assert_eq!(pre_absorb_ref_commit, actual_pre_absorb_commit);
 
+        assert_eq!(
+            extract_commit_messages(&ctx.repo),
+            vec![
+                "fixup! Initial commit.\n",
+                "fixup! Initial commit.\n",
+                "Initial commit.",
+            ]
+        );
+
         log_utils::assert_log_messages_are(
             capturing_logger.visible_logs(),
             vec![
@@ -1495,6 +1506,74 @@ mod tests {
         assert!(is_something_in_index);
     }
 
+    #[test]
+    fn squash_flag() {
+        let ctx = repo_utils::prepare_and_stage();
+
+        // run 'git-absorb'
+        let mut capturing_logger = log_utils::CapturingLogger::new();
+        let config = Config {
+            squash: true,
+            ..DEFAULT_CONFIG
+        };
+        run_with_repo(&capturing_logger.logger, &config, &ctx.repo).unwrap();
+
+        assert_eq!(
+            extract_commit_messages(&ctx.repo),
+            vec![
+                "squash! Initial commit.\n",
+                "squash! Initial commit.\n",
+                "Initial commit.",
+            ]
+        );
+
+        log_utils::assert_log_messages_are(
+            capturing_logger.visible_logs(),
+            vec![
+                &json!({"level": "INFO", "msg": "committed"}),
+                &json!({"level": "INFO", "msg": "committed"}),
+                &json!({
+                    "level": "INFO",
+                    "msg": "To squash the new commits, rebase:",
+                    "command": "git rebase --interactive --autosquash --autostash --root",
+                }),
+            ],
+        );
+    }
+
+    #[test]
+    fn run_with_squash_config_option() {
+        let ctx = repo_utils::prepare_and_stage();
+
+        repo_utils::set_config_flag(&ctx.repo, "absorb.createSquashCommits");
+
+        // run 'git-absorb'
+        let mut capturing_logger = log_utils::CapturingLogger::new();
+        run_with_repo(&capturing_logger.logger, &DEFAULT_CONFIG, &ctx.repo).unwrap();
+
+        assert_eq!(
+            extract_commit_messages(&ctx.repo),
+            vec![
+                "squash! Initial commit.\n",
+                "squash! Initial commit.\n",
+                "Initial commit.",
+            ]
+        );
+
+        log_utils::assert_log_messages_are(
+            capturing_logger.visible_logs(),
+            vec![
+                &json!({"level": "INFO", "msg": "committed"}),
+                &json!({"level": "INFO", "msg": "committed"}),
+                &json!({
+                    "level": "INFO",
+                    "msg": "To squash the new commits, rebase:",
+                    "command": "git rebase --interactive --autosquash --autostash --root",
+                }),
+            ],
+        );
+    }
+
     #[test]
     fn dry_run_flag() {
         let ctx = repo_utils::prepare_and_stage();
@@ -1814,6 +1893,23 @@ mod tests {
         assert_eq!(actual_msg, expected_msg);
     }
 
+    /// Perform a revwalk from HEAD, extracting the commit messages.
+    fn extract_commit_messages(repo: &git2::Repository) -> Vec<String> {
+        let mut revwalk = repo.revwalk().unwrap();
+        revwalk.push_head().unwrap();
+
+        let mut messages = Vec::new();
+
+        for oid in revwalk {
+            let commit = repo.find_commit(oid.unwrap()).unwrap();
+            if let Some(message) = commit.message() {
+                messages.push(message.to_string());
+            }
+        }
+
+        messages
+    }
+
     const DEFAULT_CONFIG: Config = Config {
         dry_run: false,
         force_author: false,
@@ -1823,6 +1919,7 @@ mod tests {
         rebase_options: &Vec::new(),
         whole_file: false,
         one_fixup_per_commit: false,
+        squash: false,
         message: None,
     };
 }

src/main.rs

@@ -44,6 +44,9 @@ struct Cli {
     /// Only generate one fixup per commit
     #[clap(long, short = 'F')]
     one_fixup_per_commit: bool,
+    /// Create squash commits instead of fixup
+    #[clap(long, short = 's')]
+    squash: bool,
     /// Commit message body that is given to all fixup commits
     #[clap(long, short)]
     message: Option<String>,
@@ -62,6 +65,7 @@ fn main() {
         gen_completions,
         whole_file,
         one_fixup_per_commit,
+        squash,
         message,
     } = Cli::parse();
 
@@ -113,6 +117,7 @@ fn main() {
             rebase_options: &rebase_options,
             whole_file,
             one_fixup_per_commit,
+            squash,
             message: message.as_deref(),
         },
     ) {