core tests: Convert tests that are effectively unit tests to be one

(standard android junit tests). Provides implementations for
android platform utils needed (in unit test environment):
1. android.util.Log, 2. android.text.TextUtils.isEmpty()

core/build.gradle

@@ -79,6 +79,9 @@ dependencies {
     } else {
         System.out.println("core: free build hack, skipping some dependencies")
     }
+
+    testImplementation 'junit:junit:4.12'
+
 }
 
 allprojects {

core/src/test/java/android/text/TextUtils.java

@@ -0,0 +1,32 @@
+package android.text;
+
+/**
+ * A slim-down version of standard {@link android.text.TextUtils} to be used in unit tests.
+ */
+public class TextUtils {
+
+    /**
+     * Returns true if a and b are equal, including if they are both null.
+     * <p><i>Note: In platform versions 1.1 and earlier, this method only worked well if
+     * both the arguments were instances of String.</i></p>
+     * @param a first CharSequence to check
+     * @param b second CharSequence to check
+     * @return true if a and b are equal
+     */
+    public static boolean equals(CharSequence a, CharSequence b) {
+        if (a == b) return true;
+        int length;
+        if (a != null && b != null && (length = a.length()) == b.length()) {
+            if (a instanceof String && b instanceof String) {
+                return a.equals(b);
+            } else {
+                for (int i = 0; i < length; i++) {
+                    if (a.charAt(i) != b.charAt(i)) return false;
+                }
+                return true;
+            }
+        }
+        return false;
+    }
+
+}

core/src/test/java/android/util/Log.java

@@ -0,0 +1,245 @@
+package android.util;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+
+/**
+ * A stub for {@link android.util.Log} to be used in unit tests.
+ *
+ * It outputs the log statements to standard error.
+ */
+public final class Log {
+
+    /**
+     * Priority constant for the println method; use Log.v.
+     */
+    public static final int VERBOSE = 2;
+
+    /**
+     * Priority constant for the println method; use Log.d.
+     */
+    public static final int DEBUG = 3;
+
+    /**
+     * Priority constant for the println method; use Log.i.
+     */
+    public static final int INFO = 4;
+
+    /**
+     * Priority constant for the println method; use Log.w.
+     */
+    public static final int WARN = 5;
+
+    /**
+     * Priority constant for the println method; use Log.e.
+     */
+    public static final int ERROR = 6;
+
+    /**
+     * Priority constant for the println method.
+     */
+    public static final int ASSERT = 7;
+
+    private Log() {
+    }
+
+    /**
+     * Send a {@link #VERBOSE} log message.
+     * @param tag Used to identify the source of a log message.  It usually identifies
+     *        the class or activity where the log call occurs.
+     * @param msg The message you would like logged.
+     */
+    public static int v(String tag, String msg) {
+        return println_native(LOG_ID_MAIN, VERBOSE, tag, msg);
+    }
+
+    /**
+     * Send a {@link #VERBOSE} log message and log the exception.
+     * @param tag Used to identify the source of a log message.  It usually identifies
+     *        the class or activity where the log call occurs.
+     * @param msg The message you would like logged.
+     * @param tr An exception to log
+     */
+    public static int v(String tag, String msg, Throwable tr) {
+        return printlns(LOG_ID_MAIN, VERBOSE, tag, msg, tr);
+    }
+
+    /**
+     * Send a {@link #DEBUG} log message.
+     * @param tag Used to identify the source of a log message.  It usually identifies
+     *        the class or activity where the log call occurs.
+     * @param msg The message you would like logged.
+     */
+    public static int d(String tag, String msg) {
+        return println_native(LOG_ID_MAIN, DEBUG, tag, msg);
+    }
+
+    /**
+     * Send a {@link #DEBUG} log message and log the exception.
+     * @param tag Used to identify the source of a log message.  It usually identifies
+     *        the class or activity where the log call occurs.
+     * @param msg The message you would like logged.
+     * @param tr An exception to log
+     */
+    public static int d(String tag, String msg, Throwable tr) {
+        return printlns(LOG_ID_MAIN, DEBUG, tag, msg, tr);
+    }
+
+    /**
+     * Send an {@link #INFO} log message.
+     * @param tag Used to identify the source of a log message.  It usually identifies
+     *        the class or activity where the log call occurs.
+     * @param msg The message you would like logged.
+     */
+    public static int i(String tag, String msg) {
+        return println_native(LOG_ID_MAIN, INFO, tag, msg);
+    }
+
+    /**
+     * Send a {@link #INFO} log message and log the exception.
+     * @param tag Used to identify the source of a log message.  It usually identifies
+     *        the class or activity where the log call occurs.
+     * @param msg The message you would like logged.
+     * @param tr An exception to log
+     */
+    public static int i(String tag, String msg, Throwable tr) {
+        return printlns(LOG_ID_MAIN, INFO, tag, msg, tr);
+    }
+
+    /**
+     * Send a {@link #WARN} log message.
+     * @param tag Used to identify the source of a log message.  It usually identifies
+     *        the class or activity where the log call occurs.
+     * @param msg The message you would like logged.
+     */
+    public static int w(String tag, String msg) {
+        return println_native(LOG_ID_MAIN, WARN, tag, msg);
+    }
+
+    /**
+     * Send a {@link #WARN} log message and log the exception.
+     * @param tag Used to identify the source of a log message.  It usually identifies
+     *        the class or activity where the log call occurs.
+     * @param msg The message you would like logged.
+     * @param tr An exception to log
+     */
+    public static int w(String tag, String msg, Throwable tr) {
+        return printlns(LOG_ID_MAIN, WARN, tag, msg, tr);
+    }
+
+    /**
+     * Checks to see whether or not a log for the specified tag is loggable at the specified level.
+     *
+     * @return true in all cases (for unit test environment)
+     */
+    public static boolean isLoggable(String tag, int level) {
+        return true;
+    }
+
+    /*
+     * Send a {@link #WARN} log message and log the exception.
+     * @param tag Used to identify the source of a log message.  It usually identifies
+     *        the class or activity where the log call occurs.
+     * @param tr An exception to log
+     */
+    public static int w(String tag, Throwable tr) {
+        return printlns(LOG_ID_MAIN, WARN, tag, "", tr);
+    }
+
+    /**
+     * Send an {@link #ERROR} log message.
+     * @param tag Used to identify the source of a log message.  It usually identifies
+     *        the class or activity where the log call occurs.
+     * @param msg The message you would like logged.
+     */
+    public static int e(String tag, String msg) {
+        return println_native(LOG_ID_MAIN, ERROR, tag, msg);
+    }
+
+    /**
+     * Send a {@link #ERROR} log message and log the exception.
+     * @param tag Used to identify the source of a log message.  It usually identifies
+     *        the class or activity where the log call occurs.
+     * @param msg The message you would like logged.
+     * @param tr An exception to log
+     */
+    public static int e(String tag, String msg, Throwable tr) {
+        return printlns(LOG_ID_MAIN, ERROR, tag, msg, tr);
+    }
+
+    /**
+     * What a Terrible Failure: Report a condition that should never happen.
+     * The error will always be logged at level ASSERT with the call stack.
+     * Depending on system configuration, a report may be added to the
+     * {@link android.os.DropBoxManager} and/or the process may be terminated
+     * immediately with an error dialog.
+     * @param tag Used to identify the source of a log message.
+     * @param msg The message you would like logged.
+     */
+    public static int wtf(String tag, String msg) {
+        return wtf(LOG_ID_MAIN, tag, msg, null, false, false);
+    }
+
+    /**
+     * Like {@link #wtf(String, String)}, but also writes to the log the full
+     * call stack.
+     * @hide
+     */
+    public static int wtfStack(String tag, String msg) {
+        return wtf(LOG_ID_MAIN, tag, msg, null, true, false);
+    }
+
+    /**
+     * What a Terrible Failure: Report an exception that should never happen.
+     * Similar to {@link #wtf(String, String)}, with an exception to log.
+     * @param tag Used to identify the source of a log message.
+     * @param tr An exception to log.
+     */
+    public static int wtf(String tag, Throwable tr) {
+        return wtf(LOG_ID_MAIN, tag, tr.getMessage(), tr, false, false);
+    }
+
+    /**
+     * What a Terrible Failure: Report an exception that should never happen.
+     * Similar to {@link #wtf(String, Throwable)}, with a message as well.
+     * @param tag Used to identify the source of a log message.
+     * @param msg The message you would like logged.
+     * @param tr An exception to log.  May be null.
+     */
+    public static int wtf(String tag, String msg, Throwable tr) {
+        return wtf(LOG_ID_MAIN, tag, msg, tr, false, false);
+    }
+
+    /**
+     * Priority Constant for wtf.
+     * Added for this custom Log implementation, not in android sources.
+     */
+    private static final int WTF = 8;
+    static int wtf(int logId, String tag, String msg, Throwable tr, boolean localStack,
+                   boolean system) {
+        return printlns(LOG_ID_MAIN, WTF, tag, msg, tr);
+    }
+
+    private static final int LOG_ID_MAIN = 0;
+
+    private static final String[] PRIORITY_ABBREV = { "0", "1", "V", "D", "I", "W", "E", "A", "WTF" };
+
+    private static int println_native(int bufID, int priority, String tag, String msg) {
+        String res = PRIORITY_ABBREV[priority] + "/" + tag + " " + msg + System.lineSeparator();
+        System.err.print(res);
+        return res.length();
+    }
+
+    private static int printlns(int bufID, int priority, String tag, String msg,
+                               Throwable tr) {
+        StringWriter trSW = new StringWriter();
+        if (tr != null) {
+            trSW.append(" , Exception: ");
+            PrintWriter trPW = new PrintWriter(trSW);
+            tr.printStackTrace(trPW);
+            trPW.flush();
+        }
+        return println_native(bufID, priority, tag, msg + trSW.toString());
+    }
+
+}

core/src/test/java/de/danoeh/antennapod/core/feed/FeedItemTest.java

@@ -1,22 +1,26 @@
 package de.danoeh.antennapod.core.feed;
 
-import android.test.AndroidTestCase;
+import org.junit.Before;
+import org.junit.Test;
 
 import static de.danoeh.antennapod.core.feed.FeedItemMother.anyFeedItemWithImage;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
-public class FeedItemTest extends AndroidTestCase {
+public class FeedItemTest {
 
     private FeedItem original;
     private FeedImage originalImage;
     private FeedItem changedFeedItem;
 
-    @Override
-    protected void setUp() {
+    @Before
+    public void setUp() {
         original = anyFeedItemWithImage();
         originalImage = original.getImage();
         changedFeedItem = anyFeedItemWithImage();
     }
 
+    @Test
     public void testUpdateFromOther_feedItemImageDownloadUrlChanged() throws Exception {
         setNewFeedItemImageDownloadUrl();
 
@@ -25,6 +29,7 @@ public class FeedItemTest extends AndroidTestCase {
         feedItemImageWasUpdated();
     }
 
+    @Test
     public void testUpdateFromOther_feedItemImageRemoved() throws Exception {
         feedItemImageRemoved();
 
@@ -33,6 +38,7 @@ public class FeedItemTest extends AndroidTestCase {
         feedItemImageWasNotUpdated();
     }
 
+    @Test
     public void testUpdateFromOther_feedItemImageAdded() throws Exception {
         feedItemHadNoImage();
         setNewFeedItemImageDownloadUrl();

core/src/test/java/de/danoeh/antennapod/core/feed/FeedTest.java

@@ -1,41 +1,49 @@
 package de.danoeh.antennapod.core.feed;
 
-import android.test.AndroidTestCase;
+import org.junit.Before;
+import org.junit.Test;
 
 import static de.danoeh.antennapod.core.feed.FeedImageMother.anyFeedImage;
 import static de.danoeh.antennapod.core.feed.FeedMother.anyFeed;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
-public class FeedTest extends AndroidTestCase {
+public class FeedTest {
 
     private Feed original;
     private FeedImage originalImage;
     private Feed changedFeed;
 
-    @Override
-    protected void setUp() {
+    @Before
+    public void setUp() {
         original = anyFeed();
         originalImage = original.getImage();
         changedFeed = anyFeed();
     }
 
+    @Test
     public void testCompareWithOther_feedImageDownloadUrlChanged() throws Exception {
         setNewFeedImageDownloadUrl();
 
         feedHasChanged();
     }
 
+    @Test
     public void testCompareWithOther_sameFeedImage() throws Exception {
         changedFeed.setImage(anyFeedImage());
 
         feedHasNotChanged();
     }
 
+    @Test
     public void testCompareWithOther_feedImageRemoved() throws Exception {
         feedImageRemoved();
 
         feedHasNotChanged();
     }
 
+    @Test
     public void testUpdateFromOther_feedImageDownloadUrlChanged() throws Exception {
         setNewFeedImageDownloadUrl();
 
@@ -44,6 +52,7 @@ public class FeedTest extends AndroidTestCase {
         feedImageWasUpdated();
     }
 
+    @Test
     public void testUpdateFromOther_feedImageRemoved() throws Exception {
         feedImageRemoved();
 
@@ -52,6 +61,7 @@ public class FeedTest extends AndroidTestCase {
         feedImageWasNotUpdated();
     }
 
+    @Test
     public void testUpdateFromOther_feedImageAdded() throws Exception {
         feedHadNoImage();
         setNewFeedImageDownloadUrl();

core/src/test/java/de/danoeh/antennapod/core/util/LongLongMapTest.java

@@ -1,9 +1,12 @@
 package de.danoeh.antennapod.core.util;
 
-import android.test.AndroidTestCase;
+import org.junit.Test;
 
-public class LongLongMapTest extends AndroidTestCase {
+import static org.junit.Assert.assertEquals;
 
+public class LongLongMapTest {
+
+    @Test
     public void testEmptyMap() {
         LongIntMap map = new LongIntMap();
         assertEquals(0, map.size());
@@ -16,6 +19,7 @@ public class LongLongMapTest extends AndroidTestCase {
         assertEquals(1, map.hashCode());
     }
 
+    @Test
     public void testSingleElement() {
         LongIntMap map = new LongIntMap();
         map.put(17, 42);
@@ -28,6 +32,7 @@ public class LongLongMapTest extends AndroidTestCase {
         assertEquals(true, map.delete(17));
     }
 
+    @Test
     public void testAddAndDelete() {
         LongIntMap map = new LongIntMap();
         for(int i=0; i < 100; i++) {
@@ -44,6 +49,7 @@ public class LongLongMapTest extends AndroidTestCase {
         }
     }
 
+    @Test
     public void testOverwrite() {
         LongIntMap map = new LongIntMap();
         map.put(17, 42);