Mostly Fix up deleting the branch you're on

codebase2/codebase-sqlite/U/Codebase/Sqlite/Queries.hs

@@ -3871,7 +3871,7 @@ deleteProject projectId = do
 --  After deleting `topic`:
 --
 --    main <- topic2
-deleteProjectBranch :: ProjectId -> ProjectBranchId -> Transaction ()
+deleteProjectBranch :: (HasCallStack) => ProjectId -> ProjectBranchId -> Transaction ()
 deleteProjectBranch projectId branchId = do
   maybeParentBranchId :: Maybe ProjectBranchId <-
     queryMaybeCol

unison-cli/src/Unison/Codebase/Editor/HandleInput/DeleteBranch.hs

@@ -5,6 +5,7 @@ module Unison.Codebase.Editor.HandleInput.DeleteBranch
   )
 where
 
+import Data.List qualified as List
 import U.Codebase.Sqlite.DbId (ProjectBranchId, ProjectId)
 import U.Codebase.Sqlite.Project qualified as Sqlite
 import U.Codebase.Sqlite.ProjectBranch qualified as Sqlite
@@ -41,11 +42,13 @@ handleDeleteBranch projectAndBranchNamesToDelete = do
       Cli.runTransaction . runMaybeT $
         asum
           [ parentBranch (branchToDelete ^. #projectId) (branchToDelete ^. #parentBranchId),
-            findMainBranchInProject (currentProject ^. #projectId),
-            findAnyBranchInProject (currentProject ^. #projectId),
-            findAnyBranchInCodebase,
+            findMainBranchInProjectExcept (currentProject ^. #projectId) (branchToDelete ^. #branchId),
+            -- Any branch in the codebase except the one we're deleting
+            findAnyBranchInProjectExcept (branchToDelete ^. #projectId) (branchToDelete ^. #branchId),
+            findAnyBranchInCodebaseExcept (branchToDelete ^. #projectId) (branchToDelete ^. #branchId),
             createDummyProject
           ]
+
     nextLoc <- mayNextLocation `whenNothing` projectCreate False Nothing
     Cli.switchProject nextLoc
   doDeleteProjectBranch projectAndBranchToDelete
@@ -54,23 +57,24 @@ handleDeleteBranch projectAndBranchNamesToDelete = do
     parentBranch projectId mayParentBranchId = do
       parentBranchId <- hoistMaybe mayParentBranchId
       pure (ProjectAndBranch projectId parentBranchId)
-    findMainBranchInProject :: ProjectId -> MaybeT Sqlite.Transaction (ProjectAndBranch ProjectId ProjectBranchId)
-    findMainBranchInProject projectId = do
+    findMainBranchInProjectExcept :: ProjectId -> ProjectBranchId -> MaybeT Sqlite.Transaction (ProjectAndBranch ProjectId ProjectBranchId)
+    findMainBranchInProjectExcept projectId exceptBranchId = do
       branch <- MaybeT $ Queries.loadProjectBranchByName projectId (unsafeFrom @Text "main")
+      guard (branch ^. #branchId /= exceptBranchId)
       pure (ProjectAndBranch projectId (branch ^. #branchId))
 
-    findAnyBranchInProject :: ProjectId -> MaybeT Sqlite.Transaction (ProjectAndBranch ProjectId ProjectBranchId)
-    findAnyBranchInProject projectId = do
-      (someBranchId, _) <- MaybeT . fmap listToMaybe $ Queries.loadAllProjectBranchesBeginningWith projectId Nothing
+    findAnyBranchInProjectExcept :: ProjectId -> ProjectBranchId -> MaybeT Sqlite.Transaction (ProjectAndBranch ProjectId ProjectBranchId)
+    findAnyBranchInProjectExcept projectId exceptBranchId = do
+      (someBranchId, _) <- MaybeT . fmap (List.find (\(branchId, _) -> branchId /= exceptBranchId)) $ Queries.loadAllProjectBranchesBeginningWith projectId Nothing
       pure (ProjectAndBranch projectId someBranchId)
-    findAnyBranchInCodebase :: MaybeT Sqlite.Transaction (ProjectAndBranch ProjectId ProjectBranchId)
-    findAnyBranchInCodebase = do
-      (_, pbIds) <- MaybeT . fmap listToMaybe $ Queries.loadAllProjectBranchNamePairs
+    findAnyBranchInCodebaseExcept :: ProjectId -> ProjectBranchId -> MaybeT Sqlite.Transaction (ProjectAndBranch ProjectId ProjectBranchId)
+    findAnyBranchInCodebaseExcept exceptProjectId exceptBranchId = do
+      (_, pbIds) <- MaybeT . fmap (List.find (\(_, ids) -> ids /= ProjectAndBranch exceptProjectId exceptBranchId)) $ Queries.loadAllProjectBranchNamePairs
       pure pbIds
     createDummyProject = error "TODO: create new branch or project if we  delete the last branch you're on."
 
 -- | Delete a project branch and record an entry in the reflog.
-doDeleteProjectBranch :: ProjectAndBranch Sqlite.Project Sqlite.ProjectBranch -> Cli ()
+doDeleteProjectBranch :: (HasCallStack) => ProjectAndBranch Sqlite.Project Sqlite.ProjectBranch -> Cli ()
 doDeleteProjectBranch projectAndBranch = do
   Cli.runTransaction do
     Queries.deleteProjectBranch projectAndBranch.project.projectId projectAndBranch.branch.branchId

unison-cli/src/Unison/Codebase/Editor/HandleInput/DeleteProject.hs

@@ -4,7 +4,6 @@ module Unison.Codebase.Editor.HandleInput.DeleteProject
   )
 where
 
-import Data.Function (on)
 import U.Codebase.Sqlite.Queries qualified as Queries
 import Unison.Cli.Monad (Cli)
 import Unison.Cli.Monad qualified as Cli
@@ -20,16 +19,16 @@ handleDeleteProject :: ProjectName -> Cli ()
 handleDeleteProject projectName = do
   ProjectPath currentProject _ _ <- Cli.getCurrentProjectPath
 
-  deletedProject <-
+  projectToDelete <-
     Cli.runTransactionWithRollback \rollback -> do
-      project <-
-        Queries.loadProjectByName projectName & onNothingM do
-          rollback (Output.LocalProjectDoesntExist projectName)
-      Queries.deleteProject (project ^. #projectId)
-      pure project
+      Queries.loadProjectByName projectName & onNothingM do
+        rollback (Output.LocalProjectDoesntExist projectName)
 
   -- If the user is on the project that they're deleting, we create a new project to switch
   -- to.
-  when (((==) `on` (view #projectId)) deletedProject currentProject) do
+  when ((projectToDelete ^. #projectId) == (currentProject ^. #projectId)) do
     nextLoc <- projectCreate False Nothing
     Cli.switchProject nextLoc
+
+  Cli.runTransaction do
+    Queries.deleteProject (projectToDelete ^. #projectId)

unison-src/transcripts/delete-project-branch.md

@@ -25,3 +25,9 @@ You can delete the only branch in a project.
 ```ucm
 foo/main> delete.branch /main
 ```
+
+You can delete the last branch in the codebase
+
+```ucm
+scratch/main> delete.branch scratch/main
+```

unison-src/transcripts/delete-project.output.md

@@ -43,7 +43,7 @@ scratch/main> projects
 foo/main> delete.project foo
 
   🎉 I've created the project with the randomly-chosen name
-  helpful-ladybug (use `project.rename <new-name>` to change
+  outstanding-rhino (use `project.rename <new-name>` to change
   it).
 
   🎨 Type `ui` to explore this project's code in your browser.
@@ -61,7 +61,7 @@ foo/main> delete.project foo
 scratch/main> projects
 
   1. bar
-  2. helpful-ladybug
+  2. outstanding-rhino
   3. scratch
 
 ```