tui: improve handle_background_color: short-circuit (#11067)

* handle_background_color: short-circuit if handled already

* Unit tests for handle_background_color

* set waiting_for_bg_response to false in tui_terminal_after_startup
  By then it should have been received.

1 files changed, 139 insertions, 0 deletions

diff --git a/test/unit/tui_spec.lua b/test/unit/tui_spec.lua
new file mode 100644
index 0000000000..47dbd87b71
--- /dev/null
+++ b/test/unit/tui_spec.lua
@@ -0,0 +1,139 @@
+local helpers = require("test.unit.helpers")(after_each)
+local cimport = helpers.cimport
+local eq = helpers.eq
+local ffi = helpers.ffi
+local itp = helpers.gen_itp(it)
+local to_cstr = helpers.to_cstr
+
+local cinput = cimport("./src/nvim/tui/input.h")
+local rbuffer = cimport("./test/unit/fixtures/rbuffer.h")
+local globals = cimport("./src/nvim/globals.h")
+local multiqueue = cimport("./test/unit/fixtures/multiqueue.h")
+
+itp('handle_background_color', function()
+  local handle_background_color = cinput.ut_handle_background_color
+  local term_input = ffi.new('TermInput', {})
+  local events = globals.main_loop.thread_events
+
+  -- Short-circuit when not waiting for response.
+  term_input.waiting_for_bg_response = false
+  eq(false, handle_background_color(term_input))
+
+  local capacity = 100
+  local rbuf = ffi.gc(rbuffer.rbuffer_new(capacity), rbuffer.rbuffer_free)
+  term_input.read_stream.buffer = rbuf
+
+  local function assert_bg(colorspace, color, bg)
+    local term_response = '\027]11;'..colorspace..':'..color..'\007'
+    rbuffer.rbuffer_write(rbuf, to_cstr(term_response), #term_response)
+
+    term_input.waiting_for_bg_response = true
+    eq(true, handle_background_color(term_input))
+    eq(false, term_input.waiting_for_bg_response)
+    eq(1, multiqueue.multiqueue_size(events))
+
+    local event = multiqueue.multiqueue_get(events)
+    local bg_event = ffi.cast("Event*", event.argv[1])
+    eq(bg, ffi.string(bg_event.argv[0]))
+
+    -- Buffer has been consumed.
+    eq(0, rbuf.size)
+  end
+
+  assert_bg('rgb', '0000/0000/0000', 'dark')
+  assert_bg('rgb', 'ffff/ffff/ffff', 'light')
+  assert_bg('rgb', '000/000/000', 'dark')
+  assert_bg('rgb', 'fff/fff/fff', 'light')
+  assert_bg('rgb', '00/00/00', 'dark')
+  assert_bg('rgb', 'ff/ff/ff', 'light')
+  assert_bg('rgb', '0/0/0', 'dark')
+  assert_bg('rgb', 'f/f/f', 'light')
+
+  assert_bg('rgb', 'f/0/0', 'dark')
+  assert_bg('rgb', '0/f/0', 'light')
+  assert_bg('rgb', '0/0/f', 'dark')
+
+  assert_bg('rgb', '1/1/1', 'dark')
+  assert_bg('rgb', '2/2/2', 'dark')
+  assert_bg('rgb', '3/3/3', 'dark')
+  assert_bg('rgb', '4/4/4', 'dark')
+  assert_bg('rgb', '5/5/5', 'dark')
+  assert_bg('rgb', '6/6/6', 'dark')
+  assert_bg('rgb', '7/7/7', 'dark')
+  assert_bg('rgb', '8/8/8', 'light')
+  assert_bg('rgb', '9/9/9', 'light')
+  assert_bg('rgb', 'a/a/a', 'light')
+  assert_bg('rgb', 'b/b/b', 'light')
+  assert_bg('rgb', 'c/c/c', 'light')
+  assert_bg('rgb', 'd/d/d', 'light')
+  assert_bg('rgb', 'e/e/e', 'light')
+
+  assert_bg('rgb', '0/e/0', 'light')
+  assert_bg('rgb', '0/d/0', 'light')
+  assert_bg('rgb', '0/c/0', 'dark')
+  assert_bg('rgb', '0/b/0', 'dark')
+
+  assert_bg('rgb', 'f/0/f', 'dark')
+  assert_bg('rgb', 'f/1/f', 'dark')
+  assert_bg('rgb', 'f/2/f', 'dark')
+  assert_bg('rgb', 'f/3/f', 'light')
+  assert_bg('rgb', 'f/4/f', 'light')
+
+  assert_bg('rgba', '0000/0000/0000/0000', 'dark')
+  assert_bg('rgba', '0000/0000/0000/ffff', 'dark')
+  assert_bg('rgba', 'ffff/ffff/ffff/0000', 'light')
+  assert_bg('rgba', 'ffff/ffff/ffff/ffff', 'light')
+  assert_bg('rgba', '000/000/000/000', 'dark')
+  assert_bg('rgba', '000/000/000/fff', 'dark')
+  assert_bg('rgba', 'fff/fff/fff/000', 'light')
+  assert_bg('rgba', 'fff/fff/fff/fff', 'light')
+  assert_bg('rgba', '00/00/00/00', 'dark')
+  assert_bg('rgba', '00/00/00/ff', 'dark')
+  assert_bg('rgba', 'ff/ff/ff/00', 'light')
+  assert_bg('rgba', 'ff/ff/ff/ff', 'light')
+  assert_bg('rgba', '0/0/0/0', 'dark')
+  assert_bg('rgba', '0/0/0/f', 'dark')
+  assert_bg('rgba', 'f/f/f/0', 'light')
+  assert_bg('rgba', 'f/f/f/f', 'light')
+
+
+  -- Incomplete sequence: not necessarily correct behavior, but tests it.
+  local term_response = '\027]11;rgba:f/f/f/f'  -- missing '\007
+  rbuffer.rbuffer_write(rbuf, to_cstr(term_response), #term_response)
+
+  term_input.waiting_for_bg_response = true
+  eq(true, term_input.waiting_for_bg_response)
+  eq(false, handle_background_color(term_input))
+  eq(false, term_input.waiting_for_bg_response)
+
+  eq(0, multiqueue.multiqueue_size(events))
+  eq(0, rbuf.size)
+
+
+  -- Does nothing when not at start of buffer.
+  term_response = '123\027]11;rgba:f/f/f/f\007456'
+  rbuffer.rbuffer_write(rbuf, to_cstr(term_response), #term_response)
+
+  term_input.waiting_for_bg_response = true
+  eq(true, term_input.waiting_for_bg_response)
+  eq(false, handle_background_color(term_input))
+  eq(true, term_input.waiting_for_bg_response)
+
+  eq(0, multiqueue.multiqueue_size(events))
+  eq(#term_response, rbuf.size)
+  rbuffer.rbuffer_consumed(rbuf, #term_response)
+
+
+  -- Keeps trailing buffer.
+  term_response = '\027]11;rgba:f/f/f/f\007456'
+  rbuffer.rbuffer_write(rbuf, to_cstr(term_response), #term_response)
+
+  term_input.waiting_for_bg_response = true
+  eq(true, term_input.waiting_for_bg_response)
+  eq(true, handle_background_color(term_input))
+  eq(false, term_input.waiting_for_bg_response)
+
+  eq(1, multiqueue.multiqueue_size(events))
+  eq(3, rbuf.size)
+  rbuffer.rbuffer_consumed(rbuf, rbuf.size)
+end)