how to see bitcoin blockchain and addressess for testnet
Blockchain.info does appear to support testnet blocks and transactions by simply using the "testnet" subdomain.

For example:

txid: 4200cea53a075f3081156a9d664fe05cfe108a09e26e8f20ee65e7ebe141060b

block: 1443900

address: mum6KQEwAHGDRr7HRXx7hufcsyqiGPUCtN

So in your case simply use this:

https://testnet.blockchain.info/tx/#{txid}

https://testnet.blockchain.info/address/#{address}