test: reorg #15698

Problem:
Subdirectories like "visual", "insert", "normal" encourage people to
separate *related* tests for no good reason.  Typically the _mode_ is
not the relevant topic of a test (and when it is, _then_ create
an appropriate describe() or it()).

Solution:
- Delete the various `test/functional/<mode>/` subdirectories, move
  their tests to more meaningful topics.
- Rename `…/normal/` to `…/editor/`.
  - Move or merge `…/visual/*` and `…/insert/*` tests into here where
    appropriate.
- Rename `…/eval/` to `…/vimscript/`.
  - Move `…/viml/*` into here also.

* test(reorg): insert/* => editor/mode_insert_spec.lua
* test(reorg): cmdline/* => editor/mode_cmdline_spec.lua
* test(reorg): eval core tests => eval_spec.lua

1 files changed, 61 insertions, 0 deletions

diff --git a/test/functional/editor/undo_spec.lua b/test/functional/editor/undo_spec.lua
new file mode 100644
index 0000000000..a023ca3d90
--- /dev/null
+++ b/test/functional/editor/undo_spec.lua
@@ -0,0 +1,61 @@
+local helpers = require('test.functional.helpers')(after_each)
+
+local clear = helpers.clear
+local command = helpers.command
+local expect = helpers.expect
+local feed = helpers.feed
+local insert = helpers.insert
+
+describe('u CTRL-R g- g+', function()
+  before_each(clear)
+
+  local function create_history(num_steps)
+    if num_steps == 0 then return end
+    insert('1')
+    if num_steps == 1 then return end
+    feed('o2<esc>')
+    feed('o3<esc>')
+    feed('u')
+    if num_steps == 2 then return end
+    feed('o4<esc>')
+    if num_steps == 3 then return end
+    feed('u')
+  end
+
+  local function undo_and_redo(hist_pos, undo, redo, expect_str)
+    command('enew!')
+    create_history(hist_pos)
+    local cur_contents = helpers.curbuf_contents()
+    feed(undo)
+    expect(expect_str)
+    feed(redo)
+    expect(cur_contents)
+  end
+
+  -- TODO Look for message saying 'Already at oldest change'
+  it('does nothing when no changes have happened', function()
+    undo_and_redo(0, 'u', '<C-r>', '')
+    undo_and_redo(0, 'g-', 'g+', '')
+  end)
+  it('undoes a change when at a leaf', function()
+    undo_and_redo(1, 'u', '<C-r>', '')
+    undo_and_redo(1, 'g-', 'g+', '')
+  end)
+  it('undoes a change when in a non-leaf', function()
+    undo_and_redo(2, 'u', '<C-r>', '1')
+    undo_and_redo(2, 'g-', 'g+', '1')
+  end)
+  it('undoes properly around a branch point', function()
+    undo_and_redo(3, 'u', '<C-r>', [[
+      1
+      2]])
+    undo_and_redo(3, 'g-', 'g+', [[
+      1
+      2
+      3]])
+  end)
+  it('can find the previous sequence after undoing to a branch', function()
+    undo_and_redo(4, 'u', '<C-r>', '1')
+    undo_and_redo(4, 'g-', 'g+', '1')
+  end)
+end)