feat(record): add --allow-empty

Primarily for creating new, empty commits with automatic rebasing, for when you
know you want to add something into a stack but you're not yet sure what.

Author: claytonrcarter

git-branchless-opts/src/lib.rs

@@ -329,6 +329,10 @@ pub struct RecordArgs {
     /// After making the new commit, switch back to the previous commit.
     #[clap(action, short = 's', long = "stash", conflicts_with_all(&["create", "detach"]))]
     pub stash: bool,
+
+    /// Allow creating an empty commit.
+    #[clap(action, long = "allow-empty")]
+    pub allow_empty: bool,
 }
 
 /// Display a nice graph of the commits you've recently worked on.

git-branchless-record/src/lib.rs

@@ -58,6 +58,7 @@ pub fn command_main(ctx: CommandContext, args: RecordArgs) -> EyreExitOr<()> {
         detach,
         insert,
         stash,
+        allow_empty,
     } = args;
     record(
         &effects,
@@ -68,6 +69,7 @@ pub fn command_main(ctx: CommandContext, args: RecordArgs) -> EyreExitOr<()> {
         detach,
         insert,
         stash,
+        allow_empty,
     )
 }
 
@@ -81,6 +83,7 @@ fn record(
     detach: bool,
     insert: bool,
     stash: bool,
+    allow_empty: bool,
 ) -> EyreExitOr<()> {
     let now = SystemTime::now();
     let repo = Repo::from_dir(&git_run_info.working_directory)?;
@@ -96,6 +99,7 @@ fn record(
 
         let working_copy_changes_type = snapshot.get_working_copy_changes_type()?;
         match working_copy_changes_type {
+            WorkingCopyChangesType::None if allow_empty => {}
             WorkingCopyChangesType::None => {
                 writeln!(
                     effects.get_output_stream(),
@@ -170,6 +174,9 @@ fn record(
             if working_copy_changes_type == WorkingCopyChangesType::Unstaged {
                 args.push("--all");
             }
+            if allow_empty {
+                args.push("--allow-empty");
+            }
             args
         };
         try_exit_code!(git_run_info.run_direct_no_wrapping(Some(event_tx_id), &args)?);

git-branchless-record/tests/test_record.rs

@@ -222,6 +222,36 @@ fn test_record_staged_changes_interactive() -> eyre::Result<()> {
     Ok(())
 }
 
+#[test]
+fn test_record_allow_empty() -> eyre::Result<()> {
+    let git = make_git()?;
+
+    if !git.supports_reference_transactions()? {
+        return Ok(());
+    }
+    git.init_repo()?;
+
+    {
+        let (stdout, _stderr) = git.branchless("record", &["-m", "foo", "--allow-empty"])?;
+        insta::assert_snapshot!(stdout, @r###"
+        [master 315b284] foo
+        "###);
+    }
+
+    {
+        let (stdout, _stderr) = git.run(&["show"])?;
+        insta::assert_snapshot!(stdout, @r###"
+        commit 315b28467eb85c7ba0c94fac192744c043648a30
+        Author: Testy McTestface <[email protected]>
+        Date:   Thu Oct 29 12:34:56 2020 +0000
+
+            foo
+        "###);
+    }
+
+    Ok(())
+}
+
 #[test]
 fn test_record_detach() -> eyre::Result<()> {
     let git = make_git()?;