In-app billing testing RESULT_DEVELOPER_ERROR

Question

I'm testing an app on my phone with a developer account and with test items (android.test.purchased). When I call the isBillingSupported() method, my ResponseCode is RESULT_DEVELOPER_ERROR. I didn't publish the app on the market, but I read that it is unnecessary because I use android.test.purchased.

<uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.READ_PHONE_STATE"/>
    <uses-permission android:name="android.permission.READ_OWNER_DATA"/>
    <uses-permission android:name="android.permission.WRITE_OWNER_DATA"/>        
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>  
    <uses-permission android:name="com.android.vending.BILLING"/>

I uploaded it on the market as a draft, and still no luck... I'm losing my nerve...

Answer 1

To answer the questions in your comments to @Samir's answer:

"my question is do i need to sign an app for release"

Yes, you do.

"do i need to publish on market???"

No, you don't.