1 files changed, 88 insertions, 0 deletions
diff --git a/src/test/java/com/google/devtools/build/lib/util/io/LinePrefixingOutputStreamTest.java b/src/test/java/com/google/devtools/build/lib/util/io/LinePrefixingOutputStreamTest.java
new file mode 100644
index 0000000000..b060beb50a
--- /dev/null
+++ b/src/test/java/com/google/devtools/build/lib/util/io/LinePrefixingOutputStreamTest.java
@@ -0,0 +1,88 @@
+// Copyright 2014 Google Inc. 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.lib.util.io;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+
+/**
+ * Tests {@link LinePrefixingOutputStream}.
+ */
+@RunWith(JUnit4.class)
+public class LinePrefixingOutputStreamTest {
+
+  private byte[] bytes(String string) {
+    return string.getBytes(UTF_8);
+  }
+
+  private String string(byte[] bytes) {
+    return new String(bytes, UTF_8);
+  }
+
+  private ByteArrayOutputStream out = new ByteArrayOutputStream();
+  private LinePrefixingOutputStream prefixOut =
+      new LinePrefixingOutputStream("Prefix: ", out);
+
+  @Test
+  public void testNoOutputUntilNewline() throws IOException {
+    prefixOut.write(bytes("We won't be seeing any output."));
+    assertEquals("", string(out.toByteArray()));
+  }
+
+  @Test
+  public void testOutputIfFlushed() throws IOException {
+    prefixOut.write(bytes("We'll flush after this line."));
+    prefixOut.flush();
+    assertEquals("Prefix: We'll flush after this line.\n",
+                 string(out.toByteArray()));
+  }
+
+  @Test
+  public void testAutoflushUponNewline() throws IOException {
+    prefixOut.write(bytes("Hello, newline.\n"));
+    assertEquals("Prefix: Hello, newline.\n", string(out.toByteArray()));
+  }
+
+  @Test
+  public void testAutoflushUponEmbeddedNewLine() throws IOException {
+    prefixOut.write(bytes("Hello line1.\nHello line2.\nHello line3.\n"));
+    assertEquals(
+        "Prefix: Hello line1.\nPrefix: Hello line2.\nPrefix: Hello line3.\n",
+        string(out.toByteArray()));
+  }
+
+  @Test
+  public void testBufferMaxLengthFlush() throws IOException {
+    String junk = "lots of characters of non-newline junk. ";
+    while (junk.length() < LineFlushingOutputStream.BUFFER_LENGTH) {
+      junk = junk + junk;
+    }
+    junk = junk.substring(0, LineFlushingOutputStream.BUFFER_LENGTH);
+
+    // Also test bug where write on a full buffer blows up
+    prefixOut.write(bytes(junk + junk));
+    prefixOut.write(bytes(junk + junk));
+    prefixOut.write(bytes("x"));
+    assertEquals("Prefix: " + junk + "\n" + "Prefix: " + junk + "\n"
+        + "Prefix: " + junk + "\n" + "Prefix: " + junk + "\n",
+        string(out.toByteArray()));
+  }
+}