(RFC) utils/rttc.ts: Add integer check for array indices

[thomastanck]

One way to resolve #279.

[coveralls]

Pull Request Test Coverage Report for Build 1364

• 2 of 2 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.02%) to 91.619%

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Totals
Change from base Build 1344:	0.02%
Covered Lines:	1712
Relevant Lines:	1847

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💛 - Coveralls

[martin-henz]

I find the current error message not so clear:

Current message:

Line 1: Expected integer as prop, got number.

The problem: the number is actually an integer, by any definition of the word.

My suggestion:

Line 1: Expected array index as key, got other number

[thomastanck]

Thanks for the review, I've just made the error message clearer:

Examples:

Expected array index as prop, got other number.
Expected array index as prop, got string.
...

[martin-henz]

Great!

travis chokes

[martin-henz]

Travis chokes on the recent change.

[martin-henz]

OK!