fix(session): switch session when active child/grandchild's ancestor is deleted

lua/opencode/ui/session_picker.lua

@@ -5,6 +5,28 @@ local util = require('opencode.util')
 local api = require('opencode.api')
 local Promise = require('opencode.promise')
 
+---Check whether any session id in `delete_ids` is the session itself or an ancestor
+---@param session_id string
+---@param delete_ids table<string, boolean>
+---@param all_sessions Session[]
+---@return boolean
+function M._is_session_or_ancestor_deleted(session_id, delete_ids, all_sessions)
+  local session_map = {}
+  for _, s in ipairs(all_sessions) do
+    session_map[s.id] = s
+  end
+
+  local current_id = session_id
+  while current_id do
+    if delete_ids[current_id] then
+      return true
+    end
+    local s = session_map[current_id]
+    current_id = s and s.parentID or nil
+  end
+  return false
+end
+
 ---Format session parts for session picker
 ---@param session Session object
 ---@return PickerItem
@@ -62,7 +84,12 @@ function M.pick(sessions, callback)
           to_delete_ids[s.id] = true
         end
 
-        local deleting_current = state.active_session and to_delete_ids[state.active_session.id] or false
+        local deleting_current = false
+        if state.active_session then
+          local session_mod = require('opencode.session')
+          local all_sessions = session_mod.get_all_workspace_sessions():await() or {}
+          deleting_current = M._is_session_or_ancestor_deleted(state.active_session.id, to_delete_ids, all_sessions)
+        end
 
         if deleting_current then
           local remaining = vim.tbl_filter(function(item)
@@ -73,6 +100,8 @@ function M.pick(sessions, callback)
             session_runtime.switch_session(remaining[1].id):await()
           else
             vim.notify('deleting current session, creating new session')
+            state.model.clear()
+            require('opencode.services.agent_model').ensure_current_mode():await()
             state.session.set_active(session_runtime.create_new_session():await())
           end
         end

tests/unit/session_picker_spec.lua

@@ -0,0 +1,175 @@
+-- tests/unit/session_picker_spec.lua
+-- Tests for session_picker helpers and delete action behaviour
+
+local session_picker = require('opencode.ui.session_picker')
+local session_mod = require('opencode.session')
+local session_runtime = require('opencode.services.session_runtime')
+local state = require('opencode.state')
+local store = require('opencode.state.store')
+local Promise = require('opencode.promise')
+local stub = require('luassert.stub')
+local assert = require('luassert')
+local support = require('tests.unit.services_spec_support')
+
+describe('opencode.ui.session_picker', function()
+  -- -----------------------------------------------------------------------
+  -- Pure unit tests for the helper – no mocks needed
+  -- -----------------------------------------------------------------------
+  describe('_is_session_or_ancestor_deleted', function()
+    local root = { id = 'root', parentID = nil }
+    local child = { id = 'child', parentID = 'root' }
+    local grandchild = { id = 'grandchild', parentID = 'child' }
+    local unrelated = { id = 'unrelated', parentID = nil }
+    local all_sessions = { root, child, grandchild, unrelated }
+
+    it('returns true when the session itself is in the delete set', function()
+      assert.is_true(session_picker._is_session_or_ancestor_deleted('child', { child = true }, all_sessions))
+    end)
+
+    it('returns true when the direct parent is in the delete set', function()
+      assert.is_true(session_picker._is_session_or_ancestor_deleted('child', { root = true }, all_sessions))
+    end)
+
+    it('returns true when a grandparent is in the delete set', function()
+      assert.is_true(session_picker._is_session_or_ancestor_deleted('grandchild', { root = true }, all_sessions))
+    end)
+
+    it('returns false when an unrelated session is deleted', function()
+      assert.is_false(session_picker._is_session_or_ancestor_deleted('child', { unrelated = true }, all_sessions))
+    end)
+
+    it('returns false when only a sibling is deleted', function()
+      local sibling = { id = 'sibling', parentID = 'root' }
+      assert.is_false(session_picker._is_session_or_ancestor_deleted('child', { sibling = true }, { root, child, sibling, grandchild }))
+    end)
+
+    it('returns false for a root session when an unrelated root is deleted', function()
+      assert.is_false(session_picker._is_session_or_ancestor_deleted('root', { unrelated = true }, all_sessions))
+    end)
+
+    it('returns true for root session when root itself is deleted', function()
+      assert.is_true(session_picker._is_session_or_ancestor_deleted('root', { root = true }, all_sessions))
+    end)
+  end)
+
+  -- -----------------------------------------------------------------------
+  -- Integration tests: delete action triggers switch when parent/grandparent
+  -- of the active session is deleted
+  -- -----------------------------------------------------------------------
+  describe('delete action – session switch on ancestor deletion', function()
+    local original
+    local switch_stub
+
+    local root_session = { id = 'root', parentID = nil, title = 'Root', time = { updated = '2024-01-01' } }
+    local other_root = { id = 'other-root', parentID = nil, title = 'Other', time = { updated = '2024-01-01' } }
+    local child_session = { id = 'child', parentID = 'root', title = 'Child', time = { updated = '2024-01-01' } }
+    local grandchild_session = { id = 'grandchild', parentID = 'child', title = 'Grandchild', time = { updated = '2024-01-01' } }
+
+    before_each(function()
+      original = support.snapshot_state()
+
+      vim.schedule = function(fn) fn() end
+
+      support.mock_api_client()
+
+      -- Stub delete_session on the api_client so it doesn't error
+      state.api_client.delete_session = function(_, _id)
+        return Promise.new():resolve(true)
+      end
+
+      -- Stub get_all_workspace_sessions to return our fixture tree
+      stub(session_mod, 'get_all_workspace_sessions').invokes(function()
+        return Promise.new():resolve({ root_session, other_root, child_session, grandchild_session })
+      end)
+
+      -- Stub switch_session so we can assert it was called
+      switch_stub = stub(session_runtime, 'switch_session').invokes(function(_id)
+        return Promise.new():resolve(true)
+      end)
+    end)
+
+    after_each(function()
+      support.restore_state(original)
+      if session_mod.get_all_workspace_sessions.revert then
+        session_mod.get_all_workspace_sessions:revert()
+      end
+      if session_runtime.switch_session.revert then
+        session_runtime.switch_session:revert()
+      end
+    end)
+
+    -- Helper: build a minimal opts table with items and invoke the delete fn
+    local function run_delete(active, items_in_picker, sessions_to_delete)
+      state.session.set_active(active)
+
+      -- Extract the delete action fn from the picker actions by opening a
+      -- dummy picker and grabbing the action directly from the module.
+      -- Because `pick()` closes over the actions, we re-create them here
+      -- by invoking the delete fn directly through a fake opts table.
+      local delete_fn = nil
+      -- Monkey-patch base_picker.pick to capture the actions
+      local base_picker = require('opencode.ui.base_picker')
+      local orig_pick = base_picker.pick
+      base_picker.pick = function(opts)
+        -- grab delete fn from the actions passed in
+        delete_fn = opts.actions.delete.fn
+      end
+      session_picker.pick(items_in_picker, function() end)
+      base_picker.pick = orig_pick
+
+      assert.truthy(delete_fn, 'delete fn should have been captured')
+
+      local opts = { items = vim.deepcopy(items_in_picker) }
+      delete_fn(sessions_to_delete, opts):wait()
+    end
+
+    it('switches session when the active session direct parent is deleted', function()
+      -- Active = child, deleting root (parent of child), other_root remains
+      run_delete(child_session, { root_session, other_root }, root_session)
+
+      assert.stub(switch_stub).was_called()
+      local called_with = switch_stub.calls[1].vals[1]
+      assert.equals('other-root', called_with)
+    end)
+
+    it('switches session when active session grandparent is deleted', function()
+      -- Active = grandchild, deleting root (grandparent), other_root remains
+      run_delete(grandchild_session, { root_session, other_root }, root_session)
+
+      assert.stub(switch_stub).was_called()
+      local called_with = switch_stub.calls[1].vals[1]
+      assert.equals('other-root', called_with)
+    end)
+
+    it('does NOT switch session when an unrelated root is deleted', function()
+      -- Active = child (parentID=root), deleting other_root (unrelated)
+      run_delete(child_session, { root_session, other_root }, other_root)
+
+      assert.stub(switch_stub).was_not_called()
+    end)
+
+    it('resets agent mode when all sessions are deleted and a new session is created', function()
+      local agent_model = require('opencode.services.agent_model')
+      local store = require('opencode.state.store')
+
+      -- Simulate being stuck in a subagent mode (e.g. EXPLORE)
+      store.set('current_mode', 'explore')
+
+      -- Stub ensure_current_mode to clear the mode (simulating default reset)
+      local ensure_stub = stub(agent_model, 'ensure_current_mode').invokes(function()
+        store.set('current_mode', 'default')
+        return Promise.new():resolve(true)
+      end)
+
+      -- Active = child session, only session in the picker is root (which is being deleted)
+      -- No remaining sessions after deletion
+      run_delete(child_session, { root_session }, root_session)
+
+      assert.stub(switch_stub).was_not_called()
+      assert.stub(ensure_stub).was_called()
+      assert.equals('default', state.current_mode)
+
+      ensure_stub:revert()
+    end)
+  end)
+end)