improving error messages

source/MulensModel/model.py

@@ -945,11 +945,20 @@ def _check_methods(self, methods, source):
         if len(difference) == 0:
             return
 
+        fmt = ('It is impossible to use finite source method for '
+               'a point source {:}: {:}')
         if self.n_sources == 1:
             if not self.parameters.is_finite_source():
-                raise ValueError(
-                    'It is impossible to use finite source method for '
-                    'a point source: ' + str(difference))
+                raise ValueError(fmt.format("", difference))
+        elif self.n_sources == 2:
+            if source in [1, None]:
+                if not self.parameters.source_1_parameters.is_finite_source():
+                    raise ValueError(fmt.format("no. 1", difference))
+            if source in [2, None]:
+                if not self.parameters.source_2_parameters.is_finite_source():
+                    raise ValueError(fmt.format("no. 2", difference))
+        else:
+            raise ValueError('internal error - too many sources')
 
     def get_magnification_methods(self, source=None):
         """

source/MulensModel/tests/test_Model.py

@@ -69,6 +69,35 @@ def test_finite_source_method_without_rho(self):
             model.set_magnification_methods(
                 [9, "finite_source_uniform_Gould94", 11])
 
+    def test_finite_source_method_without_rho_1(self):
+        """
+        2 source, only source 1 is finite, but we set finite method for both.
+        """
+        model = mm.Model({'t_0_1': 10, 'u_0_1': 0.2, 't_0_2': 30,
+                          'u_0_2': 0.4, 't_E': 50, 'rho_1': 0.6})
+        with self.assertRaises(ValueError):
+            model.set_magnification_methods(
+                [9, "finite_source_uniform_Gould94", 11])
+
+    def test_finite_source_method_without_rho_2(self):
+        """
+        2 source, only source 1 is finite, but we set finite method for both.
+        """
+        model = mm.Model({'t_0_1': 10, 'u_0_1': 0.2, 't_0_2': 30,
+                          'u_0_2': 0.4, 't_E': 50, 'rho_2': 0.6})
+        with self.assertRaises(ValueError):
+            model.set_magnification_methods(
+                [29, "finite_source_uniform_Gould94", 31])
+
+
+def test_model_methods():
+    """
+    Simplest model and setting point_source method.
+    It obviously should work but it's worth to check it.
+    """
+    model = mm.Model({'t_0': 10, 'u_0': 0.2, 't_E': 50})
+    model.set_magnification_methods([9, "point_source", 11])
+
 
 def test_model_parallax_definition():
     """Update parameters in an existing model"""

source/MulensModel/version.py

@@ -1 +1 @@
-__version__ = "2.22.1"
+__version__ = "2.22.2"