Add custom autocompleteResultDeserializer

src/main/kotlin/com/sourcegraph/cody/agent/CodyAgent.kt

@@ -9,6 +9,7 @@ import com.intellij.openapi.util.SystemInfoRt
 import com.intellij.util.net.HttpConfigurable
 import com.intellij.util.system.CpuArch
 import com.sourcegraph.cody.agent.protocol.*
+import com.sourcegraph.cody.agent.protocol_generated.AutocompleteResult
 import com.sourcegraph.cody.agent.protocol_generated.ClientCapabilities
 import com.sourcegraph.cody.agent.protocol_generated.ClientInfo
 import com.sourcegraph.cody.agent.protocol_generated.ProtocolTypeAdapters
@@ -293,6 +294,11 @@ private constructor(
                   // conversions
                   .registerTypeAdapter(URI::class.java, uriDeserializer)
                   .registerTypeAdapter(URI::class.java, uriSerializer)
+                  // The agent sends a badly initialized completionEvent
+                  // that is redundant for JetBrains client. The custom deserializer
+                  // simply ignores that field so we get no parsing errors.
+                  .registerTypeAdapter(
+                      AutocompleteResult::class.java, autocompleteResultDeserializer)
 
               ProtocolTypeAdapters.register(gsonBuilder)
               // This ensures that by default all enums are always serialized to their string

src/main/kotlin/com/sourcegraph/cody/agent/protocol/AutocompleteResultUtils.kt

@@ -0,0 +1,25 @@
+package com.sourcegraph.cody.agent.protocol
+
+import com.google.gson.GsonBuilder
+import com.google.gson.JsonDeserializationContext
+import com.google.gson.JsonDeserializer
+import com.google.gson.JsonElement
+import com.google.gson.JsonObject
+import com.sourcegraph.cody.agent.protocol_generated.AutocompleteResult
+import java.lang.reflect.Type
+
+private val gson = GsonBuilder().create()
+
+val autocompleteResultDeserializer =
+    JsonDeserializer { jsonElement: JsonElement?, _: Type, _: JsonDeserializationContext ->
+      val j = jsonElement?.asJsonObject
+      if (j == null || j.isJsonNull) {
+        null
+      } else if (j.isJsonPrimitive) {
+        j.asString
+      } else {
+        val obj = JsonObject()
+        obj.add("items", j["items"])
+        gson.fromJson(obj, AutocompleteResult::class.java)
+      }
+    }