test: ctrl_c_spec

- Improve test reliability by only checking for a line with the string
  we are interested in ("Interrupt").
- Try to avoid OOM by loading an existing big file instead of looping to
  create one.

1 files changed, 56 insertions, 0 deletions

diff --git a/test/functional/ex_cmds/ctrl_c_spec.lua b/test/functional/ex_cmds/ctrl_c_spec.lua
new file mode 100644
index 0000000000..5867bd6ee0
--- /dev/null
+++ b/test/functional/ex_cmds/ctrl_c_spec.lua
@@ -0,0 +1,56 @@
+local helpers = require('test.functional.helpers')(after_each)
+local Screen = require('test.functional.ui.screen')
+local clear, feed, source = helpers.clear, helpers.feed, helpers.source
+local execute = helpers.execute
+
+if helpers.pending_win32(pending) then return end
+
+describe("CTRL-C (mapped)", function()
+  before_each(function()
+    clear()
+  end)
+
+  it("interrupts :global", function()
+    source([[
+      set nomore nohlsearch undolevels=-1
+      nnoremap <C-C> <NOP>
+    ]])
+
+    execute("silent edit! test/functional/fixtures/bigfile.txt")
+    local screen = Screen.new(52, 6)
+    screen:attach()
+    screen:set_default_attr_ids({
+      [0] = {foreground = Screen.colors.White,
+             background = Screen.colors.Red},
+      [1] = {bold = true,
+             foreground = Screen.colors.SeaGreen}
+    })
+
+    screen:expect([[
+      ^0000;<control>;Cc;0;BN;;;;;N;NULL;;;;               |
+      0001;<control>;Cc;0;BN;;;;;N;START OF HEADING;;;;   |
+      0002;<control>;Cc;0;BN;;;;;N;START OF TEXT;;;;      |
+      0003;<control>;Cc;0;BN;;;;;N;END OF TEXT;;;;        |
+      0004;<control>;Cc;0;BN;;;;;N;END OF TRANSMISSION;;;;|
+                                                          |
+    ]])
+
+    local function test_ctrl_c(ms)
+      feed(":global/^/p<CR>")
+      helpers.sleep(ms)
+      feed("<C-C>")
+      screen:expect([[Interrupt]], nil, nil, nil, true)
+    end
+
+    -- The test is time-sensitive. Try different sleep values.
+    local ms_values = {1, 10, 100}
+    for i, ms in ipairs(ms_values) do
+      if i < #ms_values then
+        local status, _ = pcall(test_ctrl_c, ms)
+        if status then break end
+      else  -- Call the last attempt directly.
+        test_ctrl_c(ms)
+      end
+    end
+  end)
+end)