Use more robust logic to determine reference relationship

Previously, we used the symbol itself, which was not reliable because it
didn't distinguish between fields an objects. This commit changes the
logic to be based on `SymbolInformation.kind` from SemanticDB, that is
a more robust and idiomatic solution. Fixes #414.

Author: olafurpg

scip-semanticdb/src/main/java/com/sourcegraph/scip_semanticdb/ScipSemanticdb.java

@@ -10,7 +10,6 @@
 import com.sourcegraph.Scip;
 
 import java.io.IOException;
-import java.io.InputStream;
 import java.net.URI;
 import java.nio.file.*;
 import java.util.*;
@@ -131,7 +130,7 @@ private void processTypedDocument(Path path, PackageTable packages) {
               Scip.Relationship.newBuilder()
                   .setSymbol(typedSymbol(overriddenSymbol, overriddenSymbolPkg))
                   .setIsImplementation(true)
-                  .setIsReference(SemanticdbSymbols.isMethodOrField(info.getSymbol())));
+                  .setIsReference(supportsReferenceRelationship(info)));
         }
         if (info.hasSignature()) {
           String language =
@@ -284,7 +283,7 @@ private Integer processDocumentUnsafe(
 
       // Overrides
       if (symbolInformation.getOverriddenSymbolsCount() > 0
-          && SemanticdbSymbols.isMethodOrField(symbolInformation.getSymbol())
+          && supportsReferenceRelationship(symbolInformation)
           && occ.getRole() == Role.DEFINITION) {
         List<Integer> overriddenReferenceResultIds =
             new ArrayList<>(symbolInformation.getOverriddenSymbolsCount());
@@ -310,6 +309,17 @@ private Integer processDocumentUnsafe(
     return documentId;
   }
 
+  private static boolean supportsReferenceRelationship(SymbolInformation info) {
+    switch (info.getKind()) {
+      case CLASS:
+      case OBJECT:
+      case PACKAGE_OBJECT:
+        return false;
+      default:
+        return true;
+    }
+  }
+
   private Stream<ScipTextDocument> parseTextDocument(Path semanticdbPath) {
     try {
       return textDocumentsParseFrom(semanticdbPath).getDocumentsList().stream()

semanticdb-java/src/main/java/com/sourcegraph/semanticdb_javac/SemanticdbSymbols.java

@@ -1,7 +1,6 @@
 package com.sourcegraph.semanticdb_javac;
 
 import java.util.Objects;
-import java.util.Optional;
 
 /**
  * Utilities to construct SemanticDB symbols.
@@ -36,7 +35,7 @@ public static boolean isGlobal(String symbol) {
   }
 
   public static boolean isMethodOrField(String symbol) {
-    return symbol.endsWith(".");
+    return symbol.endsWith("#");
   }
 
   /**

tests/minimized-scala/src/main/scala/minimized/Issue414.scala

@@ -0,0 +1,14 @@
+package minimized
+
+object Issue414 {
+  trait A {
+    def b(): Unit
+  }
+  val a: A =
+    new A {
+      override def b(): Unit = {
+        print("Hello")
+      }
+    }
+  println(a.b())
+}

tests/snapshots/src/main/generated/minimized/Issue414.scala

@@ -0,0 +1,30 @@
+package minimized
+//      ^^^^^^^^^ definition minimized/
+
+object Issue414 {
+//     ^^^^^^^^ definition minimized/Issue414. object Issue414
+  trait A {
+//      ^ definition minimized/Issue414.A# trait A
+    def b(): Unit
+//      ^ definition minimized/Issue414.A#b(). def b(): Unit
+//           ^^^^ reference scala/Unit#
+  }
+  val a: A =
+//    ^ definition minimized/Issue414.a. val a: A
+//       ^ reference minimized/Issue414.A#
+    new A {
+//       definition local0 final class $anon
+//      ^ reference minimized/Issue414.A#
+//         reference java/lang/Object#`<init>`().
+      override def b(): Unit = {
+//                 ^ definition local1 def b(): Unit
+//                      ^^^^ reference scala/Unit#
+        print("Hello")
+//      ^^^^^ reference scala/Predef.print().
+      }
+    }
+  println(a.b())
+//^^^^^^^ reference scala/Predef.println(+1).
+//        ^ reference minimized/Issue414.a.
+//          ^ reference minimized/Issue414.A#b().
+}