[Android] Add support for command-line flags via annotation.

BUG=433539

Review URL: https://codereview.chromium.org/879993002

Cr-Commit-Position: refs/heads/master@{#314247}

4 files changed, 182 insertions, 0 deletions

diff --git a/base/android/java/src/org/chromium/base/BaseChromiumApplication.java b/base/android/java/src/org/chromium/base/BaseChromiumApplication.java
index a9dc2f7..8f7d39d 100644
--- a/base/android/java/src/org/chromium/base/BaseChromiumApplication.java
+++ b/base/android/java/src/org/chromium/base/BaseChromiumApplication.java
@@ -6,6 +6,7 @@ package org.chromium.base;
 
 import android.app.Activity;
 import android.app.Application;
+import android.content.Context;
 import android.os.Bundle;
 import android.view.Window;
 
@@ -96,4 +97,16 @@ public class BaseChromiumApplication extends Application {
     public void unregisterWindowFocusChangedListener(WindowFocusChangedListener listener) {
         mWindowFocusListeners.removeObserver(listener);
     }
+
+    /** Initializes the {@link CommandLine}. */
+    public void initCommandLine() {}
+
+    /**
+     * This must only be called for contexts whose application is a subclass of
+     * {@link BaseChromiumApplication}.
+     */
+    @VisibleForTesting
+    public static void initCommandLine(Context context) {
+        ((BaseChromiumApplication) context.getApplicationContext()).initCommandLine();
+    };
 }
diff --git a/base/android/java/src/org/chromium/base/CommandLine.java b/base/android/java/src/org/chromium/base/CommandLine.java
index 406f36b..43e0004 100644
--- a/base/android/java/src/org/chromium/base/CommandLine.java
+++ b/base/android/java/src/org/chromium/base/CommandLine.java
@@ -31,6 +31,7 @@ public abstract class CommandLine {
      *  Returns true if this command line contains the given switch.
      *  (Switch names ARE case-sensitive).
      */
+    @VisibleForTesting
     public abstract boolean hasSwitch(String switchString);
 
     /**
@@ -57,6 +58,7 @@ public abstract class CommandLine {
      * this action happens before the switch is needed.
      * @param switchString the switch to add.  It should NOT start with '--' !
      */
+    @VisibleForTesting
     public abstract void appendSwitch(String switchString);
 
     /**
@@ -96,6 +98,7 @@ public abstract class CommandLine {
     }
 
     // Equivalent to CommandLine::ForCurrentProcess in C++.
+    @VisibleForTesting
     public static CommandLine getInstance() {
         CommandLine commandLine = sCommandLine.get();
         assert commandLine != null;
diff --git a/base/test/android/javatests/src/org/chromium/base/test/BaseActivityInstrumentationTestCase.java b/base/test/android/javatests/src/org/chromium/base/test/BaseActivityInstrumentationTestCase.java
new file mode 100644
index 0000000..53dee4a
--- /dev/null
+++ b/base/test/android/javatests/src/org/chromium/base/test/BaseActivityInstrumentationTestCase.java
@@ -0,0 +1,118 @@
+// 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.base.test;
+
+import android.app.Activity;
+import android.content.Context;
+import android.os.SystemClock;
+import android.test.ActivityInstrumentationTestCase2;
+import android.util.Log;
+
+import org.chromium.base.BaseChromiumApplication;
+import org.chromium.base.CommandLine;
+import org.chromium.base.test.util.CommandLineFlags;
+
+import java.lang.reflect.AnnotatedElement;
+import java.lang.reflect.Method;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * Base class for all Activity-based Instrumentation tests.
+ *
+ * @param <T> The Activity type.
+ */
+public class BaseActivityInstrumentationTestCase<T extends Activity>
+        extends ActivityInstrumentationTestCase2<T> {
+
+    private static final String TAG = "BaseActivityInstrumentationTestCase";
+
+    private static final int SLEEP_INTERVAL = 50; // milliseconds
+    private static final int WAIT_DURATION = 5000; // milliseconds
+
+    /**
+     * Creates a instance for running tests against an Activity of the given class.
+     *
+     * @param activityClass The type of activity that will be tested.
+     */
+    public BaseActivityInstrumentationTestCase(Class<T> activityClass) {
+        super(activityClass);
+    }
+
+    /**
+     * Sets up the CommandLine with the appropriate flags.
+     *
+     * This will add the difference of the sets of flags specified by {@link CommandLineFlags.Add}
+     * and {@link CommandLineFlags.Remove} to the {@link org.chromium.base.CommandLine}. Note that
+     * trying to remove a flag set externally, i.e. by the command-line flags file, will not work.
+     */
+    @Override
+    protected void setUp() throws Exception {
+        super.setUp();
+
+        CommandLine.reset();
+        Context targetContext = getTargetContext();
+        assertNotNull("Unable to get a non-null target context.", targetContext);
+
+        BaseChromiumApplication.initCommandLine(targetContext);
+        Set<String> flags = getFlags(getClass().getMethod(getName()));
+        for (String flag : flags) {
+            CommandLine.getInstance().appendSwitch(flag);
+        }
+    }
+
+    /**
+     * Gets the target context.
+     *
+     * On older versions of Android, getTargetContext() may initially return null, so we have to
+     * wait for it to become available.
+     *
+     * @return The target {@link android.content.Context} if available; null otherwise.
+     */
+    private Context getTargetContext() {
+        Context targetContext = getInstrumentation().getTargetContext();
+        try {
+            long startTime = SystemClock.uptimeMillis();
+            // TODO(jbudorick): Convert this to CriteriaHelper once that moves to base/.
+            while (targetContext == null
+                    && SystemClock.uptimeMillis() - startTime < WAIT_DURATION) {
+                Thread.sleep(SLEEP_INTERVAL);
+                targetContext = getInstrumentation().getTargetContext();
+            }
+        } catch (InterruptedException e) {
+            Log.e(TAG, "Interrupted while attempting to initialize the command line.");
+        }
+        return targetContext;
+    }
+
+    private static Set<String> getFlags(AnnotatedElement element) {
+        AnnotatedElement parent = (element instanceof Method)
+                ? ((Method) element).getDeclaringClass()
+                : ((Class) element).getSuperclass();
+        Set<String> flags = (parent == null) ? new HashSet<String>() : getFlags(parent);
+
+        if (element.isAnnotationPresent(CommandLineFlags.Add.class)) {
+            flags.addAll(
+                    Arrays.asList(element.getAnnotation(CommandLineFlags.Add.class).value()));
+        }
+
+        if (element.isAnnotationPresent(CommandLineFlags.Remove.class)) {
+            List<String> flagsToRemove =
+                    Arrays.asList(element.getAnnotation(CommandLineFlags.Remove.class).value());
+            for (String flagToRemove : flagsToRemove) {
+                // If your test fails here, you have tried to remove a command-line flag via
+                // CommandLineFlags.Remove that was loaded into CommandLine via something other
+                // than CommandLineFlags.Add (probably the command-line flag file).
+                assertFalse("Unable to remove command-line flag \"" + flagToRemove + "\".",
+                        CommandLine.getInstance().hasSwitch(flagToRemove));
+            }
+            flags.removeAll(flagsToRemove);
+        }
+
+        return flags;
+    }
+}
diff --git a/base/test/android/javatests/src/org/chromium/base/test/util/CommandLineFlags.java b/base/test/android/javatests/src/org/chromium/base/test/util/CommandLineFlags.java
new file mode 100644
index 0000000..2feb83d
--- /dev/null
+++ b/base/test/android/javatests/src/org/chromium/base/test/util/CommandLineFlags.java
@@ -0,0 +1,48 @@
+// 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.base.test.util;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Inherited;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Provides annotations related to command-line flag handling.
+ *
+ * Uses of these annotations on a derived class will take precedence over uses on its base classes,
+ * so a derived class can add a command-line flag that a base class has removed (or vice versa).
+ * Similarly, uses of these annotations on a test method will take precedence over uses on the
+ * containing class.
+ *
+ * Note that this class should never be instantiated.
+ */
+public final class CommandLineFlags {
+
+    /**
+     * Adds command-line flags to the {@link org.chromium.base.CommandLine} for this test.
+     */
+    @Inherited
+    @Retention(RetentionPolicy.RUNTIME)
+    @Target({ElementType.METHOD, ElementType.TYPE})
+    public @interface Add {
+        String[] value();
+    }
+
+    /**
+     * Removes command-line flags from the {@link org.chromium.base.CommandLine} from this test.
+     *
+     * Note that this can only remove flags added via {@link Add} above.
+     */
+    @Inherited
+    @Retention(RetentionPolicy.RUNTIME)
+    @Target({ElementType.METHOD, ElementType.TYPE})
+    public @interface Remove {
+        String[] value();
+    }
+
+    private CommandLineFlags() {}
+}