Add test to detect failing reflection for netcdf-c runtime loading

Author: lesserwhirls

netcdf4/build.gradle

@@ -19,6 +19,7 @@ dependencies {
   testImplementation project(':cdm-test-utils')
 
   testImplementation 'com.google.truth:truth'
+  testImplementation 'org.jdom:jdom2'
 
   testRuntimeOnly 'ch.qos.logback:logback-classic'
 }

netcdf4/src/test/java/ucar/nc2/util/xml/TestRuntimeConfigParser.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2025 University Corporation for Atmospheric Research/Unidata
+ * See LICENSE.txt for license information.
+ */
+
+package ucar.nc2.util.xml;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.nio.file.Paths;
+import org.junit.Test;
+
+public class TestRuntimeConfigParser {
+  @Test
+  public void testReflection() throws IOException {
+    // not testing that the loading actually work, but testing that the reflection
+    // calls in the RuntimeConfigParser work
+    File nj22config =
+        Paths.get("src/test/resources/runtimeConfig/nj22Config.xml").toAbsolutePath().normalize().toFile();
+    StringBuilder errlog = new StringBuilder();
+    try (FileInputStream fis = new FileInputStream(nj22config)) {
+      RuntimeConfigParser.read(fis, errlog);
+    }
+    String err = errlog.toString();
+    assertThat(err).isNotEmpty();
+    // since this test lives in the netcdf4 subproject, we should only see
+    // the "is not on classpath" message if the reflection call used in the
+    // RuntimeConfigParser code fails
+    assertThat(err).doesNotContain("is not on classpath");
+  }
+}

netcdf4/src/test/resources/runtimeConfig/nj22Config.xml

@@ -0,0 +1,7 @@
+<nj22Config>
+  <Netcdf4Clibrary>
+    <libraryPath>/not/a/real/path</libraryPath>
+    <libraryName>netcdf</libraryName>
+    <useForReading>false</useForReading>
+  </Netcdf4Clibrary>
+</nj22Config>