Handling LevelDB errors encountered after open.

content/test/data/indexeddb/common.js

Index: content/test/data/indexeddb/common.js
diff --git a/content/test/data/indexeddb/common.js b/content/test/data/indexeddb/common.js
index 2e12d4447e2aec11c2584d2edeb00d7114199a01..d85393a3884df444f24cf809c1b173b1e1c3c772 100644
--- a/content/test/data/indexeddb/common.js
+++ b/content/test/data/indexeddb/common.js
@@ -147,3 +147,9 @@ function indexedDBTest(upgradeCallback, optionalOpenCallback) {
       openRequest.onsuccess = optionalOpenCallback;
   };
 }
+
+if (typeof String.prototype.startsWith != 'function') {

[jsbell, 2014/03/26 18:16:58]

Maybe add a comment that this is a (partial) polyfill for an ES6 method.

(Modifying prototypes of built-ins is frowned upon otherwise)

[jsbell, 2014/03/26 18:16:58]

Nit: !==

[cmumford, 2014/03/26 21:40:36]

Really? I'll look into that. I can redo this to not modify String if you want.

[jsbell, 2014/03/26 22:49:00]

These days it's "bad form" on the Web to extend built-in prototypes, since that
means the language itself can't add such a method. E.g. if "gQuery" added
String.prototype.startsWith() but computed the result by saying (new RegExp('^'
+ s)).test(this) then a sensible startsWith() might "break the web".
Object.prototype is the worst case.

But since this basically matches the ES6 semantics, it's fine. :)

+  String.prototype.startsWith = function (str) {
+    return this.indexOf(str) == 0;

[jsbell, 2014/03/26 18:16:58]

Nit: ===

+  };
+}