Remote: Support argument conversion based on defaults

pekkaklarck · pekkaklarck · commit c50f15b32449 · 2021-03-05T17:13:30.000+02:00
Returning `None` from `get_keyword_types` by default disabled argument conversion. Fixes robotframework#3873.
diff --git a/atest/robot/standard_libraries/remote/arguments.robot b/atest/robot/standard_libraries/remote/arguments.robot
@@ -12,6 +12,12 @@ Required Arguments
 Arguments With Default Values
     Check Test Case    ${TESTNAME}
 
+Defaults as tuples
+    Check Test Case    ${TESTNAME}
+
+Arguent conversion based on defaults
+    Check Test Case    ${TESTNAME}
+
 Named Arguments
     Check Test Case    ${TESTNAME}
 
diff --git a/atest/testdata/standard_libraries/remote/arguments.py b/atest/testdata/standard_libraries/remote/arguments.py
@@ -15,6 +15,11 @@ def get_keyword_types(self, name):
         kw = getattr(self.library, name)
         return getattr(kw, 'robot_types', None)
 
+    def get_keyword_arguments(self, name):
+        if name == 'defaults_as_tuples':
+            return [('first', 'eka'), ('second', 2)]
+        return RemoteServer.get_keyword_arguments(self, name)
+
 
 class Arguments(object):
 
@@ -70,6 +75,10 @@ def varargs(self, *args):
     def required_defaults_and_varargs(self, req, default='world', *varargs):
         return self._format_args(req, default, *varargs)
 
+    # Handled separately by get_keyword_arguments above.
+    def defaults_as_tuples(self, first='eka', second=2):
+        return self._format_args(first, second)
+
     def kwargs(self, **kwargs):
         return self._format_args(**kwargs)
 
diff --git a/atest/testdata/standard_libraries/remote/arguments.robot b/atest/testdata/standard_libraries/remote/arguments.robot
@@ -20,6 +20,17 @@ Arguments With Default Values
     one, two, 3              Arguments With Default Values    one    two
     one, 2 (int), 3          Arguments With Default Values    one
 
+Defaults as tuples
+    eka, 2 (int)             Defaults as tuples
+    xxx, 2 (int)             Defaults as tuples               xxx
+    xxx, 3 (int)             Defaults as tuples               xxx     3
+
+Arguent conversion based on defaults
+    xxx, 3 (int)             Defaults as tuples               xxx     3
+    xxx, 3.14 (float)        Defaults as tuples               xxx     3.14
+    xxx, yyy                 Defaults as tuples               xxx     yyy
+    0 (int), 3 (int)         Defaults as tuples               ${0}    3
+
 Named Arguments
     first, second, 3         Arguments With Default Values    first    arg2=second
     first, second, 3         Arguments With Default Values    arg1=first    arg2=second
diff --git a/doc/userguide/src/ExtendingRobotFramework/CreatingTestLibraries.rst b/doc/userguide/src/ExtendingRobotFramework/CreatingTestLibraries.rst
@@ -1195,6 +1195,8 @@ but using them as named arguments causes an error on Python side.
 
 __ https://www.python.org/dev/peps/pep-0570/
 
+.. _argument conversion:
+
 Argument types
 ~~~~~~~~~~~~~~
 
diff --git a/doc/userguide/src/ExtendingRobotFramework/RemoteLibrary.rst b/doc/userguide/src/ExtendingRobotFramework/RemoteLibrary.rst
@@ -249,26 +249,36 @@ and what they must return is explained in the table below.
    `get_keyword_tags`           Tags as a list of strings.
    ===========================  ======================================
 
-Type information can be returned either as a list mapping type names to
-arguments based on position or as a dictionary mapping argument names to
-type names directly. In practice this works the same way as when
-`specifying types using the @keyword decorator`__ with normal libraries.
-The difference is that because the XML-RPC protocol does not support
+Type information used for `argument conversion`_ can be returned either as
+a list mapping type names to arguments based on position or as a dictionary
+mapping argument names to type names directly. In practice this works the same
+way as when `specifying types using the @keyword decorator`__ with normal
+libraries. The difference is that because the XML-RPC protocol does not support
 arbitrary values, type information needs to be specified using type names
 or aliases like `'int'` or `'integer'`, not using actual types like `int`.
 Additionally `None` or `null` values may not be allowed by the XML-RPC server,
 but an empty string can be used to indicate that certain argument does not
 have type information instead.
 
+Argument conversion is supported also based on default values using the
+`same logic as with normal libraries`__. For this to work, arguments with
+default values must be returned as tuples, not as strings, the `same way
+as with dynamic libraries`__. For example, argument conversion works if
+argument information is returned like `[('count', 1), ('caseless', True)]`
+but not if it is `['count=1', 'caseless=True']`.
+
 Remote servers can also provide `general library documentation`__ to
 be used when generating documentation with the Libdoc_ tool. This information
 is got by calling `get_keyword_documentation` with special values `__intro__`
 and `__init__`.
 
-.. note:: `get_keyword_types` is new in Robot Framework 3.1.
+.. note:: `get_keyword_types` is new in Robot Framework 3.1 and support for
+          argument conversion based on defaults is new in Robot Framework 4.0.
 
 __ `Getting keyword arguments`_
 __ `Specifying argument types using @keyword decorator`_
+__ `Implicit argument types based on default values`_
+__ `Getting keyword arguments`_
 __ `Getting general library documentation`_
 
 Using `get_library_information`
diff --git a/src/robot/libraries/Remote.py b/src/robot/libraries/Remote.py
@@ -100,7 +100,8 @@ def _get_kw_info(self, kw, info, getter, default=None):
             return default
 
     def get_keyword_types(self, name):
-        return self._get_kw_info(name, 'types', self._client.get_keyword_types)
+        return self._get_kw_info(name, 'types', self._client.get_keyword_types,
+                                 default=())
 
     def get_keyword_tags(self, name):
         return self._get_kw_info(name, 'tags', self._client.get_keyword_tags)
