Add test/functional/ex_cmds/profile_spec.lua

This adds two new tests for:

    :profile dump
    :profile stop

test/functional/ex_cmds/profile_spec.lua

@@ -0,0 +1,51 @@
+require('os')
+require('lfs')
+
+local helpers  = require('test.functional.helpers')
+local eval     = helpers.eval
+local command  = helpers.command
+local eq, neq  = helpers.eq, helpers.neq
+local tempfile = os.tmpname()
+
+-- os.tmpname() also creates the file on POSIX systems. Remove it again.
+-- We just need the name, ignoring any race conditions.
+if lfs.attributes(tempfile, 'uid') then
+  os.remove(tempfile)
+end
+
+local function assert_file_exists(filepath)
+  -- Use 2-argument lfs.attributes() so no extra table gets created.
+  -- We don't really care for the uid.
+  neq(nil, lfs.attributes(filepath, 'uid'))
+end
+
+local function assert_file_exists_not(filepath)
+  eq(nil, lfs.attributes(filepath, 'uid'))
+end
+
+describe(':profile', function()
+  before_each(helpers.clear)
+
+  after_each(function()
+    if lfs.attributes(tempfile, 'uid') ~= nil then
+      os.remove(tempfile)
+    end
+  end)
+
+  it('dump', function()
+    eq(0, eval('v:profiling'))
+    command('profile start ' .. tempfile)
+    eq(1, eval('v:profiling'))
+    assert_file_exists_not(tempfile)
+    command('profile dump')
+    assert_file_exists(tempfile)
+  end)
+
+  it('stop', function()
+    command('profile start ' .. tempfile)
+    assert_file_exists_not(tempfile)
+    command('profile stop')
+    assert_file_exists(tempfile)
+    eq(0, eval('v:profiling'))
+  end)
+end)