fix: vim.eval('v:true') should return python bool #506

Signed-off-by: Mingxiang Xue <mingxiangxue@gmail.com>

Author: uzxmx

pynvim/plugin/script_host.py

@@ -194,7 +194,7 @@ def writelines(self, seq):
 
 
 def num_to_str(obj):
-    if isinstance(obj, num_types):
+    if isinstance(obj, num_types) and not isinstance(obj, bool):
         return str(obj)
     else:
         return obj

test/test_host.py

@@ -28,3 +28,10 @@ def test_host_async_error(vim):
     assert event[1] == 'nvim_error_event'
     assert 'rplugin-host: Async request caused an error:\nboom\n' \
            in h._on_error_event(None, 'boom')
+
+def test_legacy_vim_eval(vim):
+    h = ScriptHost(vim)
+    assert h.legacy_vim.eval('1') == '1'
+    assert h.legacy_vim.eval('v:null') == None
+    assert h.legacy_vim.eval('v:true') == True
+    assert h.legacy_vim.eval('v:false') == False