Added unit tests

stapleup · Feb 14, 2013 · 95f956b · 95f956b
1 parent e4adbac
commit 95f956b
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Showing 2 changed files with 52 additions and 14 deletions.
diff --git a/core/src/main/java/com/novoda/imageloader/core/cache/LruBitmapCache.java b/core/src/main/java/com/novoda/imageloader/core/cache/LruBitmapCache.java
@@ -42,22 +42,10 @@ public class LruBitmapCache implements CacheManager {
     public LruBitmapCache(Context context, int percentageOfMemoryForCache) {
         int memClass = ((ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE)).getMemoryClass();
 
-        if(memClass == 0) {
-            memClass = DEFAULT_MEMORY_CAPACITY_FOR_DEVICES_OLDER_THAN_API_LEVEL_4;
-        }
-        if(percentageOfMemoryForCache < 0) {
-            percentageOfMemoryForCache = 0;
-        }
-        if(percentageOfMemoryForCache > 81) {
-            percentageOfMemoryForCache = 80;
-        }
-        this.capacity = (int) ((memClass * percentageOfMemoryForCache * 1024L * 1024L) / 100L);
-        if(this.capacity <= 0) {
-            this.capacity = 1024*1024*4;
-        }
+        this.capacity = calculateCacheSize(memClass, percentageOfMemoryForCache);
         reset();
     }
-    
+
     /**
      * Setting the default memory size to 25% percent of the total memory 
      * available of the application.
@@ -67,6 +55,12 @@ public LruBitmapCache(Context context) {
         this(context, DEFAULT_MEMORY_CACHE_PERCENTAGE);
     }
 
+    /**
+     * Empty constructor for testing purposes
+     */
+    protected LruBitmapCache() {
+    }
+
     private void reset() {
         if (cache != null) {
             cache.evictAll();
@@ -94,4 +88,21 @@ public void clean() {
         reset();
     }
 
+    public int calculateCacheSize(int memClass, int percentageOfMemoryForCache) {
+        if(memClass == 0) {
+            memClass = DEFAULT_MEMORY_CAPACITY_FOR_DEVICES_OLDER_THAN_API_LEVEL_4;
+        }
+        if(percentageOfMemoryForCache < 0) {
+            percentageOfMemoryForCache = 0;
+        }
+        if(percentageOfMemoryForCache > 81) {
+            percentageOfMemoryForCache = 80;
+        }
+        int capacity = (int) ((memClass * percentageOfMemoryForCache * 1024L * 1024L) / 100L);
+        if(capacity <= 0) {
+            capacity = 1024*1024*4;
+        }
+
+        return capacity;
+    }
 }
diff --git a/core/src/test/java/com/novoda/imageloader/core/cache/LruBitmapCacheTest.java b/core/src/test/java/com/novoda/imageloader/core/cache/LruBitmapCacheTest.java
@@ -0,0 +1,27 @@
+package com.novoda.imageloader.core.cache;
+
+import org.junit.Test;
+
+import static junit.framework.TestCase.assertEquals;
+import static junit.framework.TestCase.assertTrue;
+
+public class LruBitmapCacheTest {
+
+    @Test
+    public void verifyCalculateCacheSizeDoesNotIntOverflow() {
+        LruBitmapCache cache = new LruBitmapCacheTestOverride();
+
+        long undividedResult = 200L * 25L * 1024L * 1024L;
+        assertTrue(undividedResult > Integer.MAX_VALUE);
+
+        long dividedResult = undividedResult / 100L;
+        assertTrue(dividedResult < Integer.MAX_VALUE);
+
+        long calculatedResult = cache.calculateCacheSize(200, 25);
+        assertEquals(dividedResult, calculatedResult);
+    }
+
+    private class LruBitmapCacheTestOverride extends LruBitmapCache {
+
+    }
+}