Ensure HTTP failure is handled in tests

[coveralls]

Pull Request Test Coverage Report for Build 783079358

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+8.9%) to 95.77%

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Totals
Change from base Build 775330813:	8.9%
Covered Lines:	883
Relevant Lines:	922

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💛 - Coveralls

[nicklaw5]

@Scorfly are you able to explain this PR? I don't understand what it's trying to achieve. Is it purely to increase test code coverage?

[Scorfly]

On code coverage, http failure was never test on every func.

Yes, this PR only aim to increase code coverage