Add --force-detach flag to bypass detached HEAD check

Author: blairconrad

Documentation/git-absorb.adoc

@@ -53,14 +53,17 @@ FLAGS
 --force-author::
         Generate fixups to commits not made by you
 
+--force-detach::
+        Generate fixups even when on a non-branch (detached) HEAD
+
 -F::
 --one-fixup-per-commit::
         Only generate one fixup per commit
 
 -f::
 --force::
-        Skip all safety checks.
-        Generate fixups to commits not made by you (as if by --force-author) and to non-branch HEADs
+        Skip all safety checks as if all --force-* flags were givenj
+        See those flags to understand the full effect of supplying --force.
 
 -w::
 --whole-file::

README.md

@@ -102,7 +102,6 @@ or the git-absorb manual page.
 ## TODO
 
 - implement remote default branch check
-- add smaller force flags to disable individual safety checks
 - stop using `failure::err_msg` and ensure all error output is actionable by the user
 - slightly more log output in the success case
 - more tests (esp main module and integration tests)

src/config.rs

@@ -36,6 +36,7 @@ pub fn unify<'config>(config: &'config Config, repo: &Repository) -> Config<'con
         force_author: config.force_author
             || config.force
             || bool_value(&repo, FORCE_AUTHOR_CONFIG_NAME, FORCE_AUTHOR_DEFAULT),
+        force_detach: config.force_detach || config.force,
         ..*config
     }
 }

src/lib.rs

@@ -12,6 +12,9 @@ use std::io::Write;
 pub struct Config<'a> {
     pub dry_run: bool,
     pub force_author: bool,
+    pub force_detach: bool,
+    // force should only be used to enable oher force_* values when unifiying the config.
+    // Do not access when disabling individual safety checks.
     pub force: bool,
     pub base: Option<&'a str>,
     pub and_rebase: bool,
@@ -30,7 +33,13 @@ fn run_with_repo(logger: &slog::Logger, config: &Config, repo: &git2::Repository
     let config = config::unify(&config, repo);
     // have force flag enable all force* flags
 
-    let stack = stack::working_stack(repo, config.base, config.force_author, config.force, logger)?;
+    let stack = stack::working_stack(
+        repo,
+        config.base,
+        config.force_author,
+        config.force_detach,
+        logger,
+    )?;
     if stack.is_empty() {
         crit!(logger, "No commits available to fix up, exiting");
         return Ok(());
@@ -614,7 +623,7 @@ mod tests {
         let result = run_with_repo(&logger, &DEFAULT_CONFIG, &ctx.repo);
         assert_eq!(
             result.err().unwrap().to_string(),
-            "HEAD is not a branch, use --force to override"
+            "HEAD is not a branch, use --force-detach to override"
         );
 
         let mut revwalk = ctx.repo.revwalk().unwrap();
@@ -645,6 +654,27 @@ mod tests {
         assert!(is_something_in_index);
     }
 
+    #[test]
+    fn detached_head_with_force_detach_flag() {
+        let ctx = repo_utils::prepare_and_stage();
+        repo_utils::detach_head(&ctx);
+        repo_utils::delete_branch(&ctx.repo, "master");
+
+        // run 'git-absorb'
+        let drain = slog::Discard;
+        let logger = slog::Logger::root(drain, o!());
+        let config = Config {
+            force_detach: true,
+            ..DEFAULT_CONFIG
+        };
+        run_with_repo(&logger, &config, &ctx.repo).unwrap();
+        let mut revwalk = ctx.repo.revwalk().unwrap();
+        revwalk.push_head().unwrap();
+
+        assert_eq!(revwalk.count(), 3);
+        assert!(nothing_left_in_index(&ctx.repo).unwrap());
+    }
+
     #[test]
     fn detached_head_with_force_flag() {
         let ctx = repo_utils::prepare_and_stage();
@@ -805,6 +835,7 @@ mod tests {
     const DEFAULT_CONFIG: Config = Config {
         dry_run: false,
         force_author: false,
+        force_detach: false,
         force: false,
         base: None,
         and_rebase: false,

src/main.rs

@@ -20,7 +20,10 @@ struct Cli {
     /// Generate fixups to commits not made by you
     #[clap(long)]
     force_author: bool,
-    /// Skip all safety checks; generate fixups to commits not made by you (as if by --force-author) and to non-branch HEADs
+    /// Generate fixups even when on a non-branch (detached) HEAD
+    #[clap(long)]
+    force_detach: bool,
+    /// Skip all safety checks as if all --force-* flags were given
     #[clap(long, short)]
     force: bool,
     /// Display more output
@@ -45,6 +48,7 @@ fn main() {
         base,
         dry_run,
         force_author,
+        force_detach,
         force,
         verbose,
         and_rebase,
@@ -94,6 +98,7 @@ fn main() {
         &git_absorb::Config {
             dry_run,
             force_author,
+            force_detach,
             force,
             base: base.as_deref(),
             and_rebase,

src/stack.rs

@@ -8,19 +8,21 @@ pub fn working_stack<'repo>(
     repo: &'repo git2::Repository,
     user_provided_base: Option<&str>,
     force_author: bool,
-    force: bool,
+    force_detach: bool,
     logger: &slog::Logger,
 ) -> Result<Vec<git2::Commit<'repo>>> {
     let head = repo.head()?;
     debug!(logger, "head found"; "head" => head.name());
 
     if !head.is_branch() {
-        if !force {
-            return Err(anyhow!("HEAD is not a branch, use --force to override"));
+        if !force_detach {
+            return Err(anyhow!(
+                "HEAD is not a branch, use --force-detach to override"
+            ));
         } else {
             warn!(
                 logger,
-                "HEAD is not a branch, but --force used to continue."
+                "HEAD is not a branch, but --force-detach used to continue."
             );
         }
     }