legacy tests: migrate test27

src/nvim/testdir/test27.in

@@ -1,20 +0,0 @@
-Test for expanding file names
-
-STARTTEST
-:!mkdir Xdir1
-:!mkdir Xdir2
-:!mkdir Xdir3
-:cd Xdir3
-:!mkdir Xdir4
-:cd ..
-:w Xdir1/file
-:w Xdir3/Xdir4/file
-:n Xdir?/*/file
-Go%:.w! test.out
-:n! Xdir?/*/nofile
-Go%:.w >>test.out
-:e! xx
-:!rm -rf Xdir1 Xdir2 Xdir3
-:qa!
-ENDTEST
-

src/nvim/testdir/test27.ok

@@ -1,2 +0,0 @@
-Xdir3/Xdir4/file
-Xdir?/*/nofile

test/functional/legacy/027_expand_file_names_spec.lua

@@ -0,0 +1,38 @@
+-- Test for expanding file names
+
+local helpers = require('test.functional.helpers')
+local clear, feed, insert = helpers.clear, helpers.feed, helpers.insert
+local execute, expect = helpers.execute, helpers.expect
+local curbuf_contents = helpers.curbuf_contents
+local eq, eval = helpers.eq, helpers.eval
+
+describe('expand file name', function()
+  setup(clear)
+
+  it('is working', function()
+    execute('set nocp')
+    execute('!mkdir Xdir1')
+    execute('!mkdir Xdir2')
+    execute('!mkdir Xdir3')
+    execute('cd Xdir3')
+    execute('!mkdir Xdir4')
+    execute('cd ..')
+    execute('w Xdir1/file')
+    execute('w Xdir3/Xdir4/file')
+    execute('n Xdir?/*/file')
+
+    -- Yank current file path to @a register
+    feed('i<C-R>%<Esc>V"ad')
+
+    -- Put @a and current file path in the current buffer
+    execute('n! Xdir?/*/nofile')
+    feed('V"ap')
+    feed('o<C-R>%<Esc>')
+
+    eq("Xdir3/Xdir4/file\nXdir?/*/nofile", curbuf_contents())
+  end)
+
+  teardown(function()
+    os.execute('rm -rf Xdir1 Xdir2 Xdir3')
+  end)
+end)