fix lsif snapshot diff with extra cheese

Author: Strum355

lsif-java/src/main/scala/com/sourcegraph/lsif_java/SemanticdbPrinters.scala

@@ -87,7 +87,11 @@ object SemanticdbPrinters {
       .append(
         symbols.get(occ.getSymbol) match {
           case Some(info) if occ.getRole == Role.DEFINITION =>
-            " " + new SignatureFormatter(info, symtab).formatSymbol() + ""
+            val sig = new SignatureFormatter(info, symtab).formatSymbol()
+            if (sig == "")
+              " " + info.getDisplayName
+            else
+              " " + sig + ""
           case _ =>
             ""
         }

lsif-java/src/main/scala/com/sourcegraph/lsif_java/commands/SnapshotLsifCommand.scala

@@ -13,7 +13,6 @@ import scala.collection.mutable
 import scala.collection.mutable.ArrayBuffer
 import scala.collection.mutable.ListBuffer
 import scala.jdk.CollectionConverters._
-
 import com.google.common.graph.EndpointPair
 import com.google.common.graph.Graph
 import com.google.common.graph.GraphBuilder
@@ -27,10 +26,8 @@ import com.sourcegraph.lsif_protocol.LsifHover
 import com.sourcegraph.lsif_protocol.LsifObject
 import com.sourcegraph.lsif_protocol.LsifPosition
 import com.sourcegraph.semanticdb_javac.Semanticdb
-import com.sourcegraph.semanticdb_javac.Semanticdb.Language
-import com.sourcegraph.semanticdb_javac.Semanticdb.SymbolOccurrence
+import com.sourcegraph.semanticdb_javac.Semanticdb.{Language, SymbolInformation, SymbolOccurrence, TextDocument}
 import com.sourcegraph.semanticdb_javac.Semanticdb.SymbolOccurrence.Role
-import com.sourcegraph.semanticdb_javac.Semanticdb.TextDocument
 import moped.annotations.CommandName
 import moped.annotations.Inline
 import moped.annotations.PositionalArguments
@@ -119,6 +116,29 @@ object SnapshotLsifCommand {
           .setSymbol(symbol)
           .build()
         doc.addOccurrences(occ)
+
+        if (isDefinition) {
+          val hover =
+            (
+              for {
+                resultSetId <- lsif.next.get(o.getId)
+                hoverId <- lsif.hoverEdges.get(resultSetId)
+                hover <- lsif.hoverVertexes.get(hoverId)
+              } yield hover
+            ).get.getContentsList.asScala.map { h =>
+              println(h.getLanguage)
+              h
+            }.find { h => h.getLanguage != Language.UNKNOWN_LANGUAGE.toString.toLowerCase }.get.getValue
+          val symInfo = SymbolInformation
+            .newBuilder()
+            // we cheese it a bit here, as this is less work than trying to reconstruct
+            // a Signature from the pretty-printed Signature, with accompanying logic
+            // to fallback to display_name in SemanticdbPrinters.scala
+            .setDisplayName(hover)
+            .setSymbol(symbol)
+            .build()
+          doc.addSymbols(symInfo)
+        }
       }
     lsif.documents.values.map(_.build()).toList
   }