[Cronet] When connection is disconnected, InputStream#read should give an exception

components/cronet/android/test/javatests/src/org/chromium/net/urlconnection/TestUtil.java

Index: components/cronet/android/test/javatests/src/org/chromium/net/urlconnection/TestUtil.java
diff --git a/components/cronet/android/test/javatests/src/org/chromium/net/urlconnection/TestUtil.java b/components/cronet/android/test/javatests/src/org/chromium/net/urlconnection/TestUtil.java
new file mode 100644
index 0000000000000000000000000000000000000000..e8dbec6d281b9ef3ed83d582f1d99f4feb7d1d1f
--- /dev/null
+++ b/components/cronet/android/test/javatests/src/org/chromium/net/urlconnection/TestUtil.java
@@ -0,0 +1,58 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.net.urlconnection;
+
+import junit.framework.Assert;
+
+import java.io.ByteArrayOutputStream;
+import java.io.InputStream;
+import java.net.HttpURLConnection;
+
+/**
+ * Helper functions and fields used in Cronet's HttpURLConnection tests.
+ */
+public class TestUtil {
+    static final String UPLOAD_DATA_STRING = "Nifty upload data!";
+    static final byte[] UPLOAD_DATA = UPLOAD_DATA_STRING.getBytes();
+    static final int REPEAT_COUNT = 100000;
+
+    /**
+     * Helper method to extract response body as a string for testing.
+     */
+    static String getResponseAsString(HttpURLConnection connection) throws Exception {
+        InputStream in = connection.getInputStream();
+        ByteArrayOutputStream out = new ByteArrayOutputStream();
+        int b;
+        while ((b = in.read()) != -1) {

[pauljensen, 2015/12/07 15:20:08]

nit: I've heard you can do this without looping with new
java.util.Scanner(in).useDelimiter("\\A").next() but I've never tried

[xunjieli, 2015/12/07 15:53:12]

I tried using a wrapper before (to read line by line), but mmenke@ suggested I
read one byte at a time. This is to know exactly what function of the
CronetInputStream we are exericising. (I have some tests, where I read a couple
of bytes at a time.) I think I will leave this one as it is. 

[pauljensen, 2015/12/07 16:07:52]

sgtm

+            out.write(b);
+        }
+        return out.toString();
+    }
+
+    /**
+     * Produces a byte array that contains {@code REPEAT_COUNT} of
+     * {@code UPLOAD_DATA_STRING}.
+     */
+    static byte[] getLargeData() {
+        byte[] largeData = new byte[REPEAT_COUNT * UPLOAD_DATA.length];
+        for (int i = 0; i < REPEAT_COUNT; i++) {
+            for (int j = 0; j < UPLOAD_DATA.length; j++) {

[pauljensen, 2015/12/07 15:20:08]

nit: might be good to replace this inner loop with System.arrayCopy

[xunjieli, 2015/12/07 15:53:12]

Done.

+                largeData[i * UPLOAD_DATA.length + j] = UPLOAD_DATA[j];
+            }
+        }
+        return largeData;
+    }
+
+    /**
+     * Helper function to check whether {@code data} is a concatenation of
+     * {@code REPEAT_COUNT} {@code UPLOAD_DATA_STRING} strings.
+     */
+    static void checkLargeData(String data) {
+        for (int i = 0; i < REPEAT_COUNT; i++) {
+            Assert.assertEquals(UPLOAD_DATA_STRING, data.substring(UPLOAD_DATA_STRING.length() * i,
+                                                            UPLOAD_DATA_STRING.length() * (i + 1)));
+        }
+    }
+}