#39: Validate extensions for proto3 (illegal)

Author: kshchepanovskyi

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

@@ -13,6 +13,7 @@
 import io.protostuff.jetbrains.plugin.psi.AntlrParserRuleNode;
 import io.protostuff.jetbrains.plugin.psi.EnumConstantNode;
 import io.protostuff.jetbrains.plugin.psi.EnumNode;
+import io.protostuff.jetbrains.plugin.psi.ExtendNode;
 import io.protostuff.jetbrains.plugin.psi.FieldLabel;
 import io.protostuff.jetbrains.plugin.psi.FieldNode;
 import io.protostuff.jetbrains.plugin.psi.GroupNode;
@@ -66,7 +67,9 @@ public void annotate(@NotNull PsiElement element, @NotNull AnnotationHolder hold
                     checkReservedFieldTags(message, fields);
                     checkReservedFieldNames(message, fields);
                 } else if (element instanceof GroupNode) {
-                    checkGroupNodeDeprecated((GroupNode)element, syntax);
+                    checkGroupNodeDeprecated((GroupNode) element, syntax);
+                } else if (element instanceof ExtendNode) {
+                    checkExtendNodeDeprecated((ExtendNode) element, syntax);
                 } else if (element instanceof FieldNode) {
                     FieldNode field = (FieldNode) element;
                     checkFieldLabel(field, syntax);
@@ -87,6 +90,14 @@ public void annotate(@NotNull PsiElement element, @NotNull AnnotationHolder hold
         }
     }
 
+    private void checkExtendNodeDeprecated(ExtendNode element, Syntax syntax) {
+        if (syntax != Syntax.PROTO3) {
+            return;
+        }
+        String message = message("error.extensions.not.supported");
+        markError(element.getNode(), null, message);
+    }
+
     private void checkGroupNodeDeprecated(GroupNode element, Syntax syntax) {
         if (syntax != Syntax.PROTO3) {
             return;

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

@@ -25,3 +25,4 @@ error.missing.field.label=Missing field label
 error.illegal.field.label=Field label "{0}" is not allowed in proto3
 error.default.value.not.supported=Default values are not supported in proto3
 error.groups.not.supported=Groups are not supported in proto3
+error.extensions.not.supported=Extensions are not supported in proto3

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

@@ -86,6 +86,10 @@ public void testProto3IllegalGroup() {
         check();
     }
 
+    public void testProto3IllegalExtend() {
+        check();
+    }
+
     private void check() {
         String file = getTestName(false) + ".proto";
         myFixture.configureByFiles(file);

src/test/resources/annotator/Proto3IllegalExtend.proto

@@ -0,0 +1,9 @@
+syntax = "proto3";
+
+package annotator;
+
+import "google/protobuf/descriptor.proto";
+
+<error descr="Extensions are not supported in proto3">extend google.protobuf.MessageOptions {
+
+}</error>