GH-310 Fixed NullPointerException when zowe.config is empty

Signed-off-by: Katsiaryna Tsytsenia <[email protected]>

Author: ktsytsen

src/main/kotlin/org/zowe/kotlinsdk/exceptions/EmptyZoweConfigFileException.kt

@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2025 IBA Group.
+ *
+ * This program and the accompanying materials are made available under the terms of the
+ * Eclipse Public License v2.0 which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-v20.html
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *   IBA Group
+ *   Zowe Community
+ *   Katsiaryna Tsytsenia
+ */
+
+package org.zowe.kotlinsdk.exceptions
+
+class EmptyZoweConfigFileException: Exception("Zowe configuration file is empty")

src/main/kotlin/org/zowe/kotlinsdk/zowe/config/utils.kt

@@ -17,6 +17,7 @@ package org.zowe.kotlinsdk.zowe.config
 import com.google.gson.Gson
 import com.starxg.keytar.Keytar
 import org.yaml.snakeyaml.Yaml
+import org.zowe.kotlinsdk.exceptions.EmptyZoweConfigFileException
 import java.io.ByteArrayInputStream
 import java.io.InputStream
 import java.nio.charset.Charset
@@ -87,9 +88,10 @@ private fun formProfiles (profiles: Map<String, ZoweConfigProfile>?) {
  * Parses JSON string to [ZoweConfig] object model.
  * @param configString JSON string with zowe config.
  * @return [ZoweConfig] object model.
+ * @throws [com.google.gson.JsonSyntaxException] and [org.zowe.kotlinsdk.exceptions.EmptyZoweConfigFileException]
  */
 fun parseConfigJson(configString: String): ZoweConfig {
-  val zoweConfig = Gson().fromJson(configString, ZoweConfig::class.java)
+  val zoweConfig = Gson().fromJson(configString, ZoweConfig::class.java) ?: throw EmptyZoweConfigFileException()
   zoweConfig.zosmfProfile = zoweConfig.profile(zoweConfig.defaults["zosmf"])
   formProfiles(zoweConfig.profiles)
   return zoweConfig
@@ -99,6 +101,7 @@ fun parseConfigJson(configString: String): ZoweConfig {
  * Reads input stream and parse it to ZoweConfig object model.
  * @param inputStream - stream with json string of zowe config.
  * @return ZoweConfig object model.
+ * @throws [com.google.gson.JsonSyntaxException] and [org.zowe.kotlinsdk.exceptions.EmptyZoweConfigFileException]
  */
 fun parseConfigJson (inputStream: InputStream): ZoweConfig = parseConfigJson(String(inputStream.readBytes()))
 

src/test/kotlin/org/zowe/kotlinsdk/zowe/ZoweConfigParsingTest.kt

@@ -17,6 +17,7 @@ package org.zowe.kotlinsdk.zowe
 import okhttp3.OkHttpClient
 import okhttp3.mockwebserver.MockWebServer
 import org.junit.jupiter.api.*
+import org.zowe.kotlinsdk.exceptions.EmptyZoweConfigFileException
 import org.zowe.kotlinsdk.zowe.client.sdk.core.ZOSConnection
 import org.zowe.kotlinsdk.zowe.config.*
 import java.net.InetSocketAddress
@@ -68,6 +69,11 @@ class ZoweConfigParsingTest: ZoweConfigTestBase() {
     checkZoweConfig(zoweConfig)
   }
 
+  @Test
+  fun testParsingEmptyJsonString() {
+    Assertions.assertThrows(EmptyZoweConfigFileException::class.java){ parseConfigJson("") }
+  }
+
   @Test
   fun testZOSConnection() {
     val zoweConfig = parseConfigJson(streamConfigJson)