Add createSquashCommits configuration option to always create squash commits

Author: blairconrad

Documentation/git-absorb.adoc

@@ -220,6 +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

@@ -1541,6 +1541,39 @@ mod tests {
         );
     }
 
+    #[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();