S2638: Avoid NPE on separator parameters (SonarSource#636)

andrea-guarino-sonarsource · web-flow · commit fcf38eec9e30 · 2020-03-13T13:36:21.000+01:00
diff --git a/python-checks/src/main/java/org/sonar/python/checks/ChangeMethodContractCheck.java b/python-checks/src/main/java/org/sonar/python/checks/ChangeMethodContractCheck.java
@@ -35,6 +35,7 @@
 import org.sonar.plugins.python.api.symbols.Symbol;
 import org.sonar.plugins.python.api.tree.AnyParameter;
 import org.sonar.plugins.python.api.tree.FunctionDef;
+import org.sonar.plugins.python.api.tree.Name;
 import org.sonar.plugins.python.api.tree.Parameter;
 import org.sonar.python.semantic.FunctionSymbolImpl;
 import org.sonar.python.tree.TreeUtils;
@@ -131,8 +132,9 @@ private static void reportOnExtraParameters(SubscriptionContext ctx, int indexFi
     List<Parameter> parameters = TreeUtils.nonTupleParameters(functionDef);
     for (int i = indexFirstExtraParams; i < parameters.size(); i++) {
       Parameter parameter = parameters.get(i);
-      if (parameter.defaultValue() == null) {
-        PreciseIssue preciseIssue = ctx.addIssue(parameter, "Remove parameter " + parameter.name().name() + " or provide default value.");
+      Name name = parameter.name();
+      if (parameter.defaultValue() == null && name != null) {
+        PreciseIssue preciseIssue = ctx.addIssue(parameter, "Remove parameter " + name.name() + " or provide default value.");
         addDefinitionSecondaryLocation(preciseIssue, definitionLocation);
       }
     }
diff --git a/python-checks/src/test/resources/checks/changeMethodContract.py b/python-checks/src/test/resources/checks/changeMethodContract.py
@@ -70,3 +70,11 @@ class Intermediate(ParentClass): ...
 class TransitivelyOverriding(Intermediate):
   def my_method(self): ... # Noncompliant
   def compliant(self, param1): ...
+
+class KeywordOnlyParameters(ParentClass):
+  def my_method(self, param1, *, param2): ... # Noncompliant
+#                                ^^^^^^
+
+class PositionalOnlyParameters(ParentClass):
+  def my_method(self, param1, /, param2): ... # Noncompliant
+#                                ^^^^^^
