Fix KeyError Exception if ENV isn't defined.

[nuno-andre]

Also, the ternary conditional isn't needed. The comparison already returns a bool.

[coveralls]

Pull Request Test Coverage Report for Build 18

• 1 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 88.679%

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Totals
Change from base Build 17:	0.0%
Covered Lines:	47
Relevant Lines:	53

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💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 18

• 1 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 88.679%

---

Totals
Change from base Build 17:	0.0%
Covered Lines:	47
Relevant Lines:	53

---

💛 - Coveralls

[greyli]

Thanks!

[greyli]

Do you actually get the KeyError? It seems that the ENV configuration variable was defined by Flask when the app instance was created.

[nuno-andre]

Thanks to you! Yes. I got it the exception with Flask 0.12.4, the last pre-1.0 (April 2018).

FLASK_DEV was introduced as of version 1.0. From 0.11 to 0.12 the recommended method of enabling the development server was through FLASK DEBUG. So before 1.0 development server and debug mode meant the same to Flask.

I made a PR to honor this equivalence that sets dev = FLASK_DEBUG only if there is not a FLASK_DEV.

[greyli]

Oh, you are right. I forgot the old version.