MatomoConsent.hasConsent return boolean

[HannesOberreiter]

Description:

Currently the fallback local cookie implementation behaves differently than the tracker for the hasConsent. The tracker always returns a boolean and the fallback a string or boolean.

This difference can also be seen in the test case, where a double bang is used to get the same results.

I would expect to behave them the same and therefore to always return a boolean for the MatomoConsent.hasConsent function.

Before

consentCookie || consentCookie !== 0

If consentCookie is a string (which it is when there is one set): consentCookie is truthy, so || short-circuits and returns the string value (e.g. "1234567890").

consentCookie = 0
consentCookie || consentCookie !== 0
# false
consentCookie = "123123123"
consentCookie || consentCookie !== 0
# '123123123'

After

!!(consentCookie && consentCookie !== 0)

If consentCookie is a string (e.g. "1234567890"), therefore consentCookie is truthy, so && evaluates the right side consentCookie !== 0 is true. Result: true (boolean)

If consentCookie is 0 it would short-circuit again, therefore the boolean transform !! is needed.

consentCookie = 0
!!(consentCookie && consentCookie !== 0)
# false
consentCookie = "123123123"
!!(consentCookie && consentCookie !== 0)
# true

Alternative

We could also add a double bang in front of the current implementation, but I think the && is more logical than the || in this case.

Review

• Functional review done
• Potential edge cases thought about (behavior of the code with strange input, with strange internal state or possible interactions with other Matomo subsystems)
• Usability review done (is anything maybe unclear or think about anything that would cause people to reach out to support)
• Security review done
• Wording review done
• Code review done
• Tests were added if useful/possible
• Reviewed for breaking changes
• Developer changelog updated if needed
• Documentation added if needed
• Existing documentation updated if needed

[nathangavin]

A minor change, all uses of hasConsent() are treating the output as boolean anyway so it is a suitable change.

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