Add test of corrupt database.

package.json

@@ -1,6 +1,6 @@
 {
     "name": "mbtiles",
-    "version": "0.1.5",
+    "version": "0.1.6",
     "description": "Utilities and tilelive integration for the MBTiles format.",
     "url": "http://github.com/mapbox/node-mbtiles",
     "author": {

test/read.test.js

@@ -10,7 +10,8 @@ var fixtures = {
     plain_2: __dirname + '/fixtures/plain_2.mbtiles',
     plain_3: __dirname + '/fixtures/plain_3.mbtiles',
     plain_4: __dirname + '/fixtures/plain_4.mbtiles',
-    non_existent: __dirname + '/fixtures/non_existent.mbtiles'
+    non_existent: __dirname + '/fixtures/non_existent.mbtiles',
+    corrupt: __dirname + '/fixtures/corrupt.mbtiles'
 };
 
 try { fs.unlink(fixtures.non_existent); } catch (err) {}
@@ -224,3 +225,23 @@ exports['get tiles from non-existent file'] = function(beforeExit) {
         assert.equal(status.error, 14);
     });
 };
+
+exports['get tiles from corrupt file'] = function(beforeExit) {
+    var status = {
+        success: 0,
+        error: 0
+    };
+    var error;
+    new MBTiles(fixtures.corrupt, function(err, mbtiles) {
+        error = err;
+    });
+
+    beforeExit(function() {
+        assert.throws(
+            function() {
+                throw err;
+            },
+            Error
+        );
+    });
+};