Go has a lightweight testing framework.

Their doc covered how you can start writing your tests. And you can read more on the testing package.

But there are a few important things they didn’t tell you.

An interface is two things: it is a set of methods, but it is also a type.

When you first learn Go, interface is always introduced as a common methods for some types.

A lesser known feature is that interface{} is a type – the empty interface with no methods. Therefore all types have already implemented interface{}.

One good use is in map[string]interface{} – where the key is string and the value is any type. You can read more about interface values.

I was integrating the new feature of iOS 8 – Today Widget Extension – into one of my app, but got rejected by the Apple review team.

I was told that the Today content is not displayed. A bug?

If it is a bug, I could not replicate it. Therefore I kindly asked for more details from the reviewer.

Every new version uploaded to iTunes Connect needs to have a different build number in order to differentiate the version.

Note: Build number (eg. 1234) is different from Version number (eg. 1.2).

The build number can be automatically increased in these few ways:

Some 8 months ago, I had a post on how to upload many localized screenshots to iTunes Connect.

The 2 tools I used was great. It saves tons of time and avoid repetitive work.

Fast forward to today, there is an even better tool – fastlane by KrauseFx.

A recommended tool for all iOS developers who localize their apps.

After upgrading to Yosemite, your brew could run into an error:

/usr/local/bin/brew: /usr/local/Library/brew.rb: /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby: bad interpreter: No such file or directory
/usr/local/bin/brew: line 23: /usr/local/Library/brew.rb: Undefined error: 0

There are a few ways to include a common library in an Xcode project.

For iOS 8, it became interesting when embedded/dynamic framework is made available for iOS. You can watch about “modern framework” in WWDC 2014.

This post is to clarify some of the concepts.

Interoperability is possible with Swift and Objective-C.

Apple has a guide on how to make the same project to use both the languages. The gist is to create a new bridging header.

A pitfall if you have 1 of these strange encounters in Xcode:

• When trying to run an app on simulator, you just couldn’t because it won’t list the simulators (but you are sure you have working simulators)!

• You have an iOS app, but Xcode thinks it is a Mac app when you try to run.

If you dig into the target/project schemes, and is still clueless, I think I could help.

Previously we mentioned a common pitfall with using a light style status bar.

This is more to understanding how to properly use UIStatusBar.