Merge pull request #102 from kiprasmel/always-sha

introduce git config option `absorb.fixupTargetAlwaysSHA`

README.md

@@ -115,6 +115,15 @@ By default, git-absorb will only consider files that you've staged to the index
 
 which tells git-absorb, when no changes are staged, to auto-stage them all, create fixup commits where possible, and unstage remaining changes from the index.
 
+### Fixup target always SHA
+
+By default, git-absorb will create fixup commits with their messages pointing to the target commit's summary, and if there are duplicate summaries, will fallback to pointing to the target's SHA. Instead, can always point to the target's SHA via:
+
+```ini
+[absorb]
+    fixupTargetAlwaysSHA = true
+```
+
 ## TODO
 
 - implement force flag

src/config.rs

@@ -7,6 +7,9 @@ pub const ONE_FIXUP_PER_COMMIT_DEFAULT: bool = false;
 pub const AUTO_STAGE_IF_NOTHING_STAGED_CONFIG_NAME: &str = "absorb.autoStageIfNothingStaged";
 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 fn max_stack(repo: &git2::Repository) -> usize {
     match repo
         .config()
@@ -36,3 +39,13 @@ pub fn auto_stage_if_nothing_staged(repo: &git2::Repository) -> bool {
         _ => AUTO_STAGE_IF_NOTHING_STAGED_DEFAULT,
     }
 }
+
+pub fn fixup_target_always_sha(repo: &git2::Repository) -> bool {
+    match repo
+        .config()
+        .and_then(|config| config.get_bool(FIXUP_TARGET_ALWAYS_SHA_CONFIG_NAME))
+    {
+        Ok(val) => val,
+        _ => FIXUP_TARGET_ALWAYS_SHA_DEFAULT,
+    }
+}

src/lib.rs

@@ -271,6 +271,8 @@ fn run_with_repo(config: &Config, repo: &git2::Repository) -> Result<()> {
         }
     }
 
+    let target_always_sha: bool = config::fixup_target_always_sha(&repo);
+
     hunks_with_commit.sort_by_key(|h| h.dest_commit.id());
     // * apply all hunks that are going to be fixed up into `dest_commit`
     // * commit the fixup
@@ -301,11 +303,14 @@ fn run_with_repo(config: &Config, repo: &git2::Repository) -> Result<()> {
             // https://docs.rs/git2/0.7.5/src/git2/repo.rs.html#998
             // https://libgit2.org/libgit2/#HEAD/group/commit/git_commit_create
             let dest_commit_id = current.dest_commit.id().to_string();
-            let dest_commit_locator = current
-                .dest_commit
-                .summary()
-                .filter(|&msg| summary_counts[msg] == 1)
-                .unwrap_or(&dest_commit_id);
+            let dest_commit_locator = match target_always_sha {
+                true => &dest_commit_id,
+                false => current
+                    .dest_commit
+                    .summary()
+                    .filter(|&msg| summary_counts[msg] == 1)
+                    .unwrap_or(&dest_commit_id),
+            };
             let diff = repo
                 .diff_tree_to_tree(Some(&head_commit.tree()?), Some(&new_head_tree), None)?
                 .stats()?;
@@ -730,4 +735,41 @@ lines
 
         assert!(nothing_left_in_index(&ctx.repo).unwrap());
     }
+
+    #[test]
+    fn fixup_message_always_commit_sha_if_configured() {
+        let ctx = prepare_and_stage();
+
+        ctx.repo
+            .config()
+            .unwrap()
+            .set_bool(config::FIXUP_TARGET_ALWAYS_SHA_CONFIG_NAME, true)
+            .unwrap();
+
+        // run 'git-absorb'
+        let drain = slog::Discard;
+        let logger = slog::Logger::root(drain, o!());
+        let config = Config {
+            dry_run: false,
+            force: false,
+            base: None,
+            and_rebase: false,
+            whole_file: false,
+            one_fixup_per_commit: true,
+            logger: &logger,
+        };
+        run_with_repo(&config, &ctx.repo).unwrap();
+        assert!(nothing_left_in_index(&ctx.repo).unwrap());
+
+        let mut revwalk = ctx.repo.revwalk().unwrap();
+        revwalk.push_head().unwrap();
+
+        let oids: Vec<git2::Oid> = revwalk.by_ref().collect::<Result<Vec<_>, _>>().unwrap();
+        assert_eq!(oids.len(), 2);
+
+        let commit = ctx.repo.find_commit(oids[0]).unwrap();
+        let actual_msg = commit.summary().unwrap();
+        let expected_msg = format!("fixup! {}", oids[1]);
+        assert_eq!(actual_msg, expected_msg);
+    }
 }