Add sign-in and token retrieval to Blimp

blimp/client/android/javatests/src/org/chromium/blimp/auth/RetryingTokenSourceTest.java

Index: blimp/client/android/javatests/src/org/chromium/blimp/auth/RetryingTokenSourceTest.java
diff --git a/blimp/client/android/javatests/src/org/chromium/blimp/auth/RetryingTokenSourceTest.java b/blimp/client/android/javatests/src/org/chromium/blimp/auth/RetryingTokenSourceTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..3bd957e070cb45c99bcd3cdf5763888517f8e52c
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+++ b/blimp/client/android/javatests/src/org/chromium/blimp/auth/RetryingTokenSourceTest.java
@@ -0,0 +1,259 @@
+// 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.blimp.auth;
+
+import android.content.Intent;
+import android.test.InstrumentationTestCase;
+import android.test.suitebuilder.annotation.SmallTest;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.Semaphore;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicReference;
+
+/**
+ * Tests the basic behavior of a {@link RetryingTokenSource}.
+ */
+public class RetryingTokenSourceTest extends InstrumentationTestCase {
+    private static final String TEST_TOKEN = "abcdefg";
+    private static final int SEMAPHORE_TIMEOUT_MS = 4000;
+
+    /**
+     * A wrapper for a {@link RetryingTokenSource} that minimizes the retry delay for testing
+     * purposes.  The original delay is still tracked.  This also implements a
+     * {@link TokenSource#Callback} and notifies {@link Semaphore}s when certain callback methods
+     * are called.
+     */
+    private static class TestRetryingTokenSource extends RetryingTokenSource {
+        private final List<Long> mRetryDelays = new ArrayList<Long>();
+        private final Semaphore mSuccessSemaphore;
+        private final Semaphore mFailSemaphore;
+        private final Semaphore mNeedsAccountSemaphore;
+
+        /**
+         * The token received from the underlying {@link TokenSource} or {@code null} if no token
+         * was received.
+         */
+        private String mReceivedToken;
+
+        private TokenSource.Callback mCallback = new TokenSource.Callback() {
+            @Override
+            public void onTokenReceived(String token) {
+                mReceivedToken = token;
+                if (mSuccessSemaphore != null) mSuccessSemaphore.release();
+            }
+
+            @Override
+            public void onTokenUnavailable(boolean isTransient) {
+                assertFalse("getToken() failed in a recoverable way for a RetryingTokenSource.",
+                        isTransient);
+                if (mFailSemaphore != null) mFailSemaphore.release();
+            }
+
+            @Override
+            public void onNeedsAccountToBeSelected(Intent intent) {
+                if (mNeedsAccountSemaphore != null) mNeedsAccountSemaphore.release();
+            }
+        };
+
+        /**
+         * @param tokenSource           The underlying {@link TokenSource} to use.
+         * @param successSemaphore      A {@link Semaphore} to track calls to
+         *                              {@link TokenSource#Callback#onTokenReceived(String)}.
+         * @param failureSemaphore      A {@link Semaphore} to track calls to
+         *                              {@link TokenSource#Callback#onTokenUnavailable(boolean)}.
+         * @param needsAccountSemaphore A {@link Semaphore} to track calls to {@link
+         *                              TokenSource#Callback#onNeedsAccountToBeSelected(Intent)}.
+         */
+        public TestRetryingTokenSource(TokenSource tokenSource, Semaphore successSemaphore,
+                Semaphore failureSemaphore, Semaphore needsAccountSemaphore) {
+            super(tokenSource);
+
+            mSuccessSemaphore = successSemaphore;
+            mFailSemaphore = failureSemaphore;
+            mNeedsAccountSemaphore = needsAccountSemaphore;
+
+            setCallback(mCallback);
+        }
+
+        /**
+         * @return The token received from the underlying {@link TokenSource} or {@code null} if
+         *         no token was received.
+         */
+        public String getReceivedToken() {
+            return mReceivedToken;
+        }
+
+        /**
+         * @return A {@link List} of the delays (in ms) that would have been between each retry
+         *         attempt.
+         */
+        public List<Long> getRetryDelays() {
+            return mRetryDelays;
+        }
+
+        /**
+         * Minimize the actual delay for testing purposes, but save the original delay to validate
+         * that the backoff is working.
+         * @param delay The original delay the {@link RetryingTokenSource} would like to use.
+         * @return      A small delay to be used during testing.
+         */
+        @Override
+        protected long finalizeRetryDelay(long delay) {
+            mRetryDelays.add(delay);
+            return 1;
+        }
+    }
+
+    private AtomicReference<TestRetryingTokenSource> buildAndTriggerTokenSource(
+            final String correctToken,
+            final int transientFailures,
+            final boolean hardFailure,
+            final Semaphore successSemaphore,
+            final Semaphore failureSemaphore,
+            final Semaphore needsAccountSemaphore) {
+        final AtomicReference<TestRetryingTokenSource> tokenSource =
+                new AtomicReference<TestRetryingTokenSource>();
+        getInstrumentation().runOnMainSync(new Runnable() {
+            @Override
+            public void run() {
+                TokenSource mockTokenSource =
+                        new MockTokenSource(correctToken, transientFailures, hardFailure);
+                tokenSource.set(new TestRetryingTokenSource(mockTokenSource,
+                        successSemaphore, failureSemaphore, needsAccountSemaphore));
+                tokenSource.get().getToken();
+                assertTrue("RetryingTokenSource is not attempting to get a token.",
+                        tokenSource.get().isRetrievingToken());
+            }
+        });
+        return tokenSource;
+    }
+
+    private void validateTokenSourceResults(
+            final AtomicReference<TestRetryingTokenSource> tokenSource,
+            final String expectedToken,
+            final int expectedTransientFailures) {
+        getInstrumentation().runOnMainSync(new Runnable() {
+            @Override
+            public void run() {
+                String token = tokenSource.get().getReceivedToken();
+                assertEquals("getToken() resulted in the wrong token.", expectedToken, token);
+
+                List<Long> delays = tokenSource.get().getRetryDelays();
+                assertEquals("getToken() resulted in an incorrect number of retries.",
+                        expectedTransientFailures + 1, delays.size());
+
+                long prevDelay = Long.MIN_VALUE;
+                for (int i = 0; i < delays.size(); i++) {
+                    long delay = delays.get(i);
+                    assertTrue("RetryingTokenSource did not increase delays between attempts "
+                            + "(" + prevDelay + " < " + delay + " failed).",
+                            prevDelay < delay);
+                    assertTrue("RetryingTokenSource used a negative delay.",
+                            delay >= 0);
+                    assertTrue("RetryingTokenSource used no delay for retries.",
+                            delay > 0 || i == 0);
+                    prevDelay = delay;
+                }
+            }
+        });
+    }
+
+    /**
+     * Tests basic behavior when the token is returned successfully.
+     * @throws InterruptedException
+     */
+    @SmallTest
+    public void testSuccessfulTokenSource() throws InterruptedException {
+        Semaphore success = new Semaphore(0);
+        Semaphore failure = new Semaphore(0);
+        Semaphore needsAccount = new Semaphore(0);
+        AtomicReference<TestRetryingTokenSource> tokenSource =
+                buildAndTriggerTokenSource(TEST_TOKEN, 0, false, success, failure, needsAccount);
+
+        // Validate that the callbacks got the expected results.
+        assertTrue("Did not receive a successful token in time.",
+                success.tryAcquire(SEMAPHORE_TIMEOUT_MS, TimeUnit.MILLISECONDS));
+        assertFalse("getToken() failed.", failure.tryAcquire());
+        assertFalse("getToken() needed an account.", needsAccount.tryAcquire());
+
+        validateTokenSourceResults(tokenSource, TEST_TOKEN, 0);
+    }
+
+    /**
+     * Tests retry behavior when there is a transient error multiple times before the token is
+     * returned successfully.
+     * @throws InterruptedException
+     */
+    @SmallTest
+    public void testRecoveringTokenSource() throws InterruptedException {
+        int failureCount = 6;
+
+        Semaphore success = new Semaphore(0);
+        Semaphore failure = new Semaphore(0);
+        Semaphore needsAccount = new Semaphore(0);
+        AtomicReference<TestRetryingTokenSource> tokenSource =
+                buildAndTriggerTokenSource(TEST_TOKEN, failureCount, false, success, failure,
+                        needsAccount);
+
+        assertTrue("Did not receive a successful token in time.",
+                success.tryAcquire(SEMAPHORE_TIMEOUT_MS, TimeUnit.MILLISECONDS));
+        assertFalse("getToken() failed.", failure.tryAcquire());
+        assertFalse("getToken() needed an account.", needsAccount.tryAcquire());
+
+        validateTokenSourceResults(tokenSource, TEST_TOKEN, failureCount);
+    }
+
+    /**
+     * Tests failure behavior for when there is an unrecoverable error after multiple transient
+     * errors.
+     * @throws InterruptedException
+     */
+    @SmallTest
+    public void testFailedTokenSource() throws InterruptedException {
+        int failureCount = 6;
+
+        Semaphore success = new Semaphore(0);
+        Semaphore failure = new Semaphore(0);
+        Semaphore needsAccount = new Semaphore(0);
+        AtomicReference<TestRetryingTokenSource> tokenSource =
+                buildAndTriggerTokenSource(TEST_TOKEN, failureCount, true, success, failure,
+                        needsAccount);
+
+        assertTrue("Did not receive a failure in time.",
+                failure.tryAcquire(SEMAPHORE_TIMEOUT_MS, TimeUnit.MILLISECONDS));
+        assertFalse("getToken() succeeded.", success.tryAcquire());
+        assertFalse("getToken() needed an account.", needsAccount.tryAcquire());
+
+        validateTokenSourceResults(tokenSource, null, failureCount);
+    }
+
+    /**
+     * Tests failure behavior for when there is an unrecoverable error after multiple transient
+     * errors.
+     * @throws InterruptedException
+     */
+    @SmallTest
+    public void testTooManyTransientFailures() throws InterruptedException {
+        int failureCount = RetryingTokenSource.MAX_NUMBER_OF_RETRIES + 1;
+
+        Semaphore success = new Semaphore(0);
+        Semaphore failure = new Semaphore(0);
+        Semaphore needsAccount = new Semaphore(0);
+        AtomicReference<TestRetryingTokenSource> tokenSource =
+                buildAndTriggerTokenSource(TEST_TOKEN, failureCount, false, success, failure,
+                        needsAccount);
+
+        assertTrue("Did not receive a failure in time.",
+                failure.tryAcquire(SEMAPHORE_TIMEOUT_MS, TimeUnit.MILLISECONDS));
+        assertFalse("getToken() succeeded.", success.tryAcquire());
+        assertFalse("getToken() needed an account.", needsAccount.tryAcquire());
+
+        // Expect one less transient error than MAX_NUMBER_OF_RETRIES.
+        validateTokenSourceResults(
+                tokenSource, null, RetryingTokenSource.MAX_NUMBER_OF_RETRIES - 1);
+    }
+}