inconsistencies in matchHeader for numbers

matchHeader has inconsistent behavior when trying to match headers that contain numbers. Due to a truthy check that was introduced to the matchStringOrRegexp method in lib/common.js in #827, numbers other than 0 get converted to string before matching but 0 does not.

Given the headers

zero: 0
one: 1

The following would happen

.matchHeader('zero', 0) -> true
.matchHeader('one', 1) -> false
.matchHeader('zero', '0') -> false
.matchHeader('one', '1') -> true

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The interface could be cleaned up in one of three ways:

1. Restrict the second argument of matchHeader to be a string, regular expression or function and throw a TypeError if anything else is passed in and modify the code in matchStringOrRegexp to use the String constructor
2. If the second argument is not a regular expression or a function, coerce into a string before comparison and perform the same modification to matchStringOrRegexp as above
3. Leave the matchHeader interface the same and modify matchStringOrRegexp to no longer do string coercion and use pattern.test(target) instead of target.match(pattern)

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I personally like doing the second option as well as changing matchStringOrRegexp to dopattern.test(target) instead of target.match(pattern)

[gr2m]

confirmed that the above tests pass now on master

[gr2m]

Hey @gurpreetatwal, we’ll have a remote hackathon on Friday, wanna join us and work on this? You can comment here #1269