executor,functests: Add print() tests, some fixes

test/functional/lua/overrides_spec.lua

@@ -0,0 +1,65 @@
+-- Test for Vim overrides of lua built-ins
+local helpers = require('test.functional.helpers')(after_each)
+
+local eq = helpers.eq
+local NIL = helpers.NIL
+local clear = helpers.clear
+local funcs = helpers.funcs
+local meths = helpers.meths
+local command = helpers.command
+local write_file = helpers.write_file
+local redir_exec = helpers.redir_exec
+
+local fname = 'Xtest-functional-lua-overrides-luafile'
+
+before_each(clear)
+
+after_each(function()
+  os.remove(fname)
+end)
+
+describe('print', function()
+  it('returns nothing', function()
+    eq(NIL, funcs.luaeval('print("abc")'))
+    eq(0, funcs.luaeval('select("#", print("abc"))'))
+  end)
+  it('allows catching printed text with :execute', function()
+    eq('\nabc', funcs.execute('lua print("abc")'))
+    eq('\nabc', funcs.execute('luado print("abc")'))
+    eq('\nabc', funcs.execute('call luaeval("print(\'abc\')")'))
+    write_file(fname, 'print("abc")')
+    eq('\nabc', funcs.execute('luafile ' .. fname))
+
+    eq('\nabc', redir_exec('lua print("abc")'))
+    eq('\nabc', redir_exec('luado print("abc")'))
+    eq('\nabc', redir_exec('call luaeval("print(\'abc\')")'))
+    write_file(fname, 'print("abc")')
+    eq('\nabc', redir_exec('luafile ' .. fname))
+  end)
+  it('handles errors in __tostring', function()
+    write_file(fname, [[
+      local meta_nilerr = { __tostring = function() error(nil) end }
+      local meta_abcerr = { __tostring = function() error("abc") end }
+      local meta_tblout = { __tostring = function() return {"TEST"} end }
+      v_nilerr = setmetatable({}, meta_nilerr)
+      v_abcerr = setmetatable({}, meta_abcerr)
+      v_tblout = setmetatable({}, meta_tblout)
+    ]])
+    eq('', redir_exec('luafile ' .. fname))
+    eq('\nE5114: Error while converting print argument #2: [NULL]',
+       redir_exec('lua print("foo", v_nilerr, "bar")'))
+    eq('\nE5114: Error while converting print argument #2: Xtest-functional-lua-overrides-luafile:2: abc',
+       redir_exec('lua print("foo", v_abcerr, "bar")'))
+    eq('\nE5114: Error while converting print argument #2: <Unknown error: lua_tolstring returned NULL for tostring result>',
+       redir_exec('lua print("foo", v_tblout, "bar")'))
+  end)
+  it('prints strings with NULs and NLs correctly', function()
+    meths.set_option('more', true)
+    eq('\nabc ^@ def\nghi^@^@^@jkl\nTEST\n\n\nT\n',
+       redir_exec([[lua print("abc \0 def\nghi\0\0\0jkl\nTEST\n\n\nT\n")]]))
+    eq('\nabc ^@ def\nghi^@^@^@jkl\nTEST\n\n\nT^@',
+       redir_exec([[lua print("abc \0 def\nghi\0\0\0jkl\nTEST\n\n\nT\0")]]))
+    eq('\nT^@', redir_exec([[lua print("T\0")]]))
+    eq('\nT\n', redir_exec([[lua print("T\n")]]))
+  end)
+end)