#39: Validate default value for proto3 (illegal)

Author: kshchepanovskyi

src/main/java/io/protostuff/jetbrains/plugin/annotator/ProtoErrorsAnnotator.java

@@ -17,15 +17,18 @@
 import io.protostuff.jetbrains.plugin.psi.FieldNode;
 import io.protostuff.jetbrains.plugin.psi.MessageField;
 import io.protostuff.jetbrains.plugin.psi.MessageNode;
+import io.protostuff.jetbrains.plugin.psi.OptionNode;
 import io.protostuff.jetbrains.plugin.psi.ProtoRootNode;
 import io.protostuff.jetbrains.plugin.psi.RangeNode;
 import io.protostuff.jetbrains.plugin.psi.RpcMethodNode;
 import io.protostuff.jetbrains.plugin.psi.ServiceNode;
 import io.protostuff.jetbrains.plugin.psi.Syntax;
+import io.protostuff.jetbrains.plugin.reference.FieldReferenceProviderImpl;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
 import org.jetbrains.annotations.NotNull;
@@ -62,7 +65,10 @@ public void annotate(@NotNull PsiElement element, @NotNull AnnotationHolder hold
                     checkReservedFieldTags(message, fields);
                     checkReservedFieldNames(message, fields);
                 } else if (element instanceof FieldNode) {
-                    checkFieldLabel((FieldNode) element, syntax);
+                    FieldNode field = (FieldNode) element;
+                    checkFieldLabel(field, syntax);
+                } else if (element instanceof OptionNode) {
+                    checkDefaultValue((OptionNode)element, syntax);
                 } else if (element instanceof EnumNode) {
                     EnumNode anEnum = (EnumNode) element;
                     List<EnumConstantNode> constants = anEnum.getConstants();
@@ -78,6 +84,24 @@ public void annotate(@NotNull PsiElement element, @NotNull AnnotationHolder hold
         }
     }
 
+    private void checkDefaultValue(@NotNull OptionNode option, Syntax syntax) {
+        if (syntax != Syntax.PROTO3) {
+            return;
+        }
+        PsiElement optionEntry = option.getParent();
+        if (optionEntry != null) {
+            PsiElement field = optionEntry.getParent();
+            if (field instanceof MessageField) {
+                String optionName = option.getOptionNameText();
+                if (Objects.equals(optionName, FieldReferenceProviderImpl.DEFAULT)) {
+                    String message = message("error.default.value.not.supported");
+                    markError(option.getNode(), null, message);
+                }
+            }
+        }
+    }
+
+
     private void checkFieldLabel(FieldNode field, Syntax syntax) {
         switch (syntax) {
             case PROTO2:

src/main/java/io/protostuff/jetbrains/plugin/reference/FieldReferenceProviderImpl.java

@@ -53,7 +53,8 @@ public class FieldReferenceProviderImpl implements FieldReferenceProvider {
 
     private static final Logger LOGGER = Logger.getInstance(FieldReferenceProviderImpl.class);
     // "default" field option (a special case)
-    private static final String DEFAULT = "default";
+    public static final String DEFAULT = "default";
+
     private static final Map<Class<? extends PsiElement>, String> TARGET_MAPPING
             = ImmutableMap.<Class<? extends PsiElement>, String>builder()
             .put(FieldNode.class, MSG_FIELD_OPTIONS)

src/main/resources/io/protostuff/protobuf-jetbrains-plugin/messages/ProtostuffBundle.properties

@@ -21,3 +21,4 @@ error.duplicate.method.name=Duplicate RPC method name: {0}
 error.missing.field.label=Missing field label
 error.illegal.field.label=Field label "{0}" is not allowed in proto3
 element.context.display={0} in {1}
+error.default.value.not.supported=Default values are not supported in proto3

src/test/java/io/protostuff/jetbrains/plugin/annotator/ProtoErrorsAnnotatorTest.java

@@ -78,6 +78,10 @@ public void testProto3IllegalRequiredFieldLabel() {
         check();
     }
 
+    public void testProto3IllegalDefaultValueOption() {
+        check();
+    }
+
     private void check() {
         String file = getTestName(false) + ".proto";
         myFixture.configureByFiles(file);

src/test/resources/annotator/Proto3IllegalDefaultValueOption.proto

@@ -0,0 +1,7 @@
+syntax = "proto3";
+
+package annotator;
+
+message TestMessage {
+    int32 field = 1 [<error descr="Default values are not supported in proto3">default = 5</error>];
+}