A more general way to create a typical workspace commit.

Let's make the type specific to what we actually need.

Author: Byron

crates/but-workspace/src/commit.rs

@@ -1,5 +1,24 @@
 use crate::WorkspaceCommit;
-use bstr::ByteSlice;
+use crate::ui::StackEntryNoOpt;
+use bstr::{BString, ByteSlice};
+
+/// A minimal stack for use by [WorkspaceCommit::new_from_stacks()].
+pub struct Stack {
+    /// The tip of the top-most branch, i.e., the most recent commit that would become the parent of new commits of the topmost stack branch.
+    pub tip: gix::ObjectId,
+    /// The short name of the stack, which is the name of the top-most branch, like `main` or `feature/branch` or `origin/tracking-some-PR`
+    /// or something entirely made up.
+    pub name: Option<BString>,
+}
+
+impl From<StackEntryNoOpt> for Stack {
+    fn from(value: StackEntryNoOpt) -> Self {
+        Stack {
+            tip: value.tip,
+            name: value.name().map(ToOwned::to_owned),
+        }
+    }
+}
 
 /// Construction
 impl<'repo> WorkspaceCommit<'repo> {
@@ -20,10 +39,11 @@ impl<'repo> WorkspaceCommit<'repo> {
     /// It still needs its tree set to something non-empty.
     ///
     /// `object_hash` is needed to create an empty tree hash.
-    pub(crate) fn create_commit_from_vb_state(
-        stacks: &[crate::ui::StackEntryNoOpt],
+    pub(crate) fn new_from_stacks(
+        stacks: impl IntoIterator<Item = impl Into<Stack>>,
         object_hash: gix::hash::Kind,
     ) -> gix::objs::Commit {
+        let stacks = stacks.into_iter().map(Into::into).collect::<Vec<_>>();
         // message that says how to get back to where they were
         let mut message = Self::GITBUTLER_WORKSPACE_COMMIT_TITLE.to_string();
         message.push_str("\n\n");
@@ -44,8 +64,8 @@ impl<'repo> WorkspaceCommit<'repo> {
         message.push_str("If you commit on this branch, GitButler will throw it away.\n\n");
         if !stacks.is_empty() {
             message.push_str("Here are the branches that are currently applied:\n");
-            for branch in stacks {
-                if let Some(name) = branch.name() {
+            for branch in &stacks {
+                if let Some(name) = &branch.name {
                     message.push_str(" - ");
                     message.push_str(name.to_str_lossy().as_ref());
                     message.push('\n');

crates/but-workspace/src/commit_engine/mod.rs

@@ -515,10 +515,7 @@ pub fn create_commit_and_update_refs(
                             .map(|stack| crate::ui::StackEntryNoOpt::try_new(repo, stack))
                             .collect::<Result<_, _>>()?;
                         stacks.sort_by(|a, b| a.name().cmp(&b.name()));
-                        let new_wc = WorkspaceCommit::create_commit_from_vb_state(
-                            &stacks,
-                            repo.object_hash(),
-                        );
+                        let new_wc = WorkspaceCommit::new_from_stacks(stacks, repo.object_hash());
                         repo.write_object(&new_wc)?.detach()
                     } else {
                         workspace_tip

crates/but-workspace/src/lib.rs

@@ -61,7 +61,8 @@ pub mod snapshot;
 
 mod changeset;
 
-mod commit;
+/// Utility types for the [`WorkspaceCommit`].
+pub(crate) mod commit;
 
 /// Types used only when obtaining head-information.
 ///

crates/but-workspace/tests/workspace/branch/apply_unapply_commit_uncommit.rs

@@ -234,13 +234,12 @@ fn auto_checkout_of_enclosing_workspace_flat() -> anyhow::Result<()> {
     let graph =
         but_graph::Graph::from_commit_traversal(b_id, b_ref.clone(), &meta, Default::default())?;
     let ws = graph.to_workspace()?;
-    // TODO: fix this - the entrypoint shouldn't alter the stack setup.
     insta::assert_snapshot!(graph_workspace(&ws), @r"
-    📕🏘️⚠️:1:gitbutler/workspace <> ✓!
-    └── ≡👉📙:0:B
-        ├── 👉📙:0:B
+    📕🏘️⚠️:1:gitbutler/workspace <> ✓! on e5d0542
+    ├── ≡👉📙:3:B on e5d0542
+    │   └── 👉📙:3:B
+    └── ≡📙:2:A on e5d0542
         └── 📙:2:A
-            └── ·e5d0542 (🏘️) ►main
     ");
 
     // Already applied (the HEAD points to it, it literally IS the workspace).