Add support for not contains json matcher

[Crow-EH]

Hi everyone.

I created this issue instead of a PR to talk about it with you first. I'm still 100% motivated to code it myself though.

Here's the issue: Today we can't make an explicit, concise and human readable test that a JSON field doesn't contain a string.

How about adding a way to negate matchers or add new negated matchers not contain / not contains ? (or even !contains)

Example / Use case

Let's say I want to test this object :

{
  a: string
  b: string
}

Additionally a and b :

• have very, very long values (e.g. URLs with many query params, tokens, etc.)
• might evolve many times in the project lifecycle (e.g. by adding params regularly)

=> I don't want to use the equals matcher because I'll have to update every tests every time, plus my tests would be over verbose.

Now let's pretend that I have to develop a new feature where:

• I need to add a new foo query param only for a
• But absolutely not for b (i.e. they have a similar method of generation and errors could be made)

I'd want to test that :

• a contains foo
• b does not contain foo

And here's what it would look like today :

And json response should match
    | field | matcher  | value         |
    | a     | contains | foo           |
    | b     | match    | ^((?!foo).)*$ |

The only way to do the second test is to match the value against ^((?!foo).)*$ with match, which is not really human readable and more error prone than a simple not contains.

The negated contains would look like this:

And json response should match
    | field | matcher      | value |
    | a     | contains     | foo   |
    | b     | not contains | foo   |

WDYT @plouc @leguellec ?

TL;DR

Need to test if a value is not contained by another one, but regexps are not human friendly :

[Crow-EH]

Here's a PR.

Not sure if I did everything right, so don't hesitate to roast me. 😄

Thank you !

[plouc]

Maybe we could use does not or doesn't instead as gherkin is supposed to be human readable, this way we'll have something like props | doesn't contain | something.

Also I think we could support this for all matchers, what do you think?

[Crow-EH]

Good point!
I'll rename it and extend to every matchers.

[plouc]

perfect, thanks!

[Crow-EH]

Done !

I added support for every matchers negation with: !, not, does not, doesn't, is not, isn't.