[TEST] Change es.node.mode default for tests to local

In order to speed up test execution we should run in local mode by
default. CI builds will still use network builds all the time.

Closes #6624

TESTING.asciidoc

@@ -20,13 +20,13 @@ mvn clean package -DskipTests
 
 To disable and enable network transport, set the `Des.node.mode`.
 
-Use network transport (default):
+Use network transport:
 
 ------------------------------------
 -Des.node.mode=network
 ------------------------------------
 
-Use local transport:
+Use local transport (default since 1.3):
 
 -------------------------------------
 -Des.node.mode=local

src/main/java/org/elasticsearch/common/Strings.java

@@ -219,6 +219,25 @@ public class Strings {
         return hasLength((CharSequence) str);
     }
 
+
+    /**
+     * Check that the given CharSequence is either <code>null</code> or of length 0.
+     * Note: Will return <code>false</code> for a CharSequence that purely consists of whitespace.
+     * <p><pre>
+     * StringUtils.isEmpty(null) = true
+     * StringUtils.isEmpty("") = true
+     * StringUtils.isEmpty(" ") = false
+     * StringUtils.isEmpty("Hello") = false
+     * </pre>
+     *
+     * @param str the CharSequence to check (may be <code>null</code>)
+     * @return <code>true</code> if the CharSequence is either null or has a zero length
+     */
+    public static boolean isEmpty(CharSequence str) {
+        return !hasLength(str);
+    }
+
+
     /**
      * Check whether the given CharSequence has actual text.
      * More specifically, returns <code>true</code> if the string not <code>null</code>,

src/test/java/org/apache/lucene/util/AbstractRandomizedTest.java

@@ -31,6 +31,7 @@ import com.carrotsearch.randomizedtesting.rules.NoInstanceHooksOverridesRule;
 import com.carrotsearch.randomizedtesting.rules.StaticFieldsInvariantRule;
 import com.carrotsearch.randomizedtesting.rules.SystemPropertiesInvariantRule;
 import org.apache.lucene.util.LuceneTestCase.SuppressCodecs;
+import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.lucene.Lucene;
 import org.elasticsearch.common.settings.ImmutableSettings;
 import org.elasticsearch.common.util.concurrent.EsExecutors;
@@ -403,4 +404,13 @@ public abstract class AbstractRandomizedTest extends RandomizedTest {
         return threadAndTestNameRule.testMethodName;
     }
 
+    static {
+        String nodeLocal = System.getProperty("es.node.mode", System.getProperty("es.node.local", ""));
+        if (Strings.isEmpty(nodeLocal)) {
+            // we default to local mode to speed up tests running in IDEs etc.
+            // compared to a mvn default value this will also work if executed from an IDE.
+            System.setProperty("es.node.mode", "local");
+        }
+    }
+
 }