Fix multi-line signatures (#480)

* Fix multi-line signature

* Remove whitespace

Author: gatesn

pyls/plugins/signature.py

@@ -20,8 +20,12 @@ def pyls_signature_help(document, position):
         return {'signatures': []}
 
     s = signatures[0]
+
+    # Docstring contains one or more lines of signature, followed by empty line, followed by docstring
+    function_sig_lines = (s.docstring().split('\n\n') or [''])[0].splitlines()
+    function_sig = ' '.join([line.strip() for line in function_sig_lines])
     sig = {
-        'label': (s.docstring().splitlines() or [''])[0],
+        'label': function_sig,
         'documentation': _utils.format_docstring(s.docstring(raw=True))
     }
 

test/plugins/test_signature.py

@@ -18,6 +18,26 @@ def main(param1, param2):
 main(
 """
 
+MULTI_LINE_DOC = """import sys
+
+def main(param1=None,
+            param2=None,
+            param3=None,
+            param4=None,
+            param5=None,
+            param6=None,
+            param7=None,
+            param8=None):
+    \"\"\" Main docstring
+
+    Args:
+        param1 (str): Docs for param1
+    \"\"\"
+    raise Exception()
+
+main(
+"""
+
 
 def test_no_signature():
     # Over blank line
@@ -44,6 +64,25 @@ def test_signature():
     assert sig_info['activeParameter'] == 0
 
 
+def test_multi_line_signature():
+    # Over '( ' in main(
+    sig_position = {'line': 17, 'character': 5}
+    doc = Document(DOC_URI, MULTI_LINE_DOC)
+
+    sig_info = signature.pyls_signature_help(doc, sig_position)
+
+    sigs = sig_info['signatures']
+    assert len(sigs) == 1
+    assert sigs[0]['label'] == (
+        'main(param1=None, param2=None, param3=None, param4=None, '
+        'param5=None, param6=None, param7=None, param8=None)'
+    )
+    assert sigs[0]['parameters'][0]['label'] == 'param1'
+    assert sigs[0]['parameters'][0]['documentation'] == 'Docs for param1'
+
+    assert sig_info['activeParameter'] == 0
+
+
 @pytest.mark.parametrize('regex,doc', [
     (signature.SPHINX, "    :param test: parameter docstring"),
     (signature.EPYDOC, "    @param test: parameter docstring"),