java,runfiles: cut all third-party dependencies

Cut all dependencies of the Java runfiles library,
so we can include its sources in @bazel_tools, and
any Java project can safely depend on it without
worrying about pulling in an incompatible version
of Guava for example.

See https://github.com/bazelbuild/bazel/issues/4460

Change-Id: I4a9314c56a2c9dc3afdf53669429750d8fb81e3b
PiperOrigin-RevId: 181968558

src/tools/runfiles/java/com/google/devtools/build/runfiles/UtilTest.java

diff --git a/src/tools/runfiles/java/com/google/devtools/build/runfiles/UtilTest.java b/src/tools/runfiles/java/com/google/devtools/build/runfiles/UtilTest.java
new file mode 100644
index 0000000..48a5f94
--- /dev/null
+++ b/src/tools/runfiles/java/com/google/devtools/build/runfiles/UtilTest.java
@@ -0,0 +1,54 @@
+// Copyright 2018 The Bazel Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.devtools.build.runfiles;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assert.fail;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Unit tests for {@link Util}. */
+@RunWith(JUnit4.class)
+public final class UtilTest {
+
+  @Test
+  public void testIsNullOrEmpty() throws Exception {
+    assertThat(Util.isNullOrEmpty(null)).isTrue();
+    assertThat(Util.isNullOrEmpty("")).isTrue();
+    assertThat(Util.isNullOrEmpty("\0")).isFalse();
+    assertThat(Util.isNullOrEmpty("some text")).isFalse();
+  }
+
+  @Test
+  public void testCheckArgument() throws Exception {
+    Util.checkArgument(true, null, null);
+
+    try {
+      Util.checkArgument(false, null, null);
+      fail("expected failure");
+    } catch (IllegalArgumentException e) {
+      assertThat(e).hasMessageThat().isEqualTo("argument validation failed");
+    }
+
+    try {
+      Util.checkArgument(false, "foo-%s", 42);
+      fail("expected failure");
+    } catch (IllegalArgumentException e) {
+      assertThat(e).hasMessageThat().isEqualTo("foo-42");
+    }
+  }
+}