Missing a "roughly" matcher for dates

[dchelimsky]

No description provided.

[fernando-nubank]

I guess we could create a roughly matcher that have different behaviors for different data types like in equals.

[philomates]

some examples of how to do this in user land:

(defn roughly-same-time [expected]
  (matcher-combinators.core/->PredMatcher
    (fn [actual]
      (and (instance? java.time.Instant actual)
           (.isAfter expected (.plus actual -5 java.time.temporal.ChronoUnit/SECONDS))
           (.isBefore expected (.plus actual 5 java.time.temporal.ChronoUnit/SECONDS))))
    (str "similar-time " expected " (+/- 5 seconds)")))

(is (match? {:scheduled-for-datetime (roughly-same-time this-month)}
            (some-expr)))

which gives mismatch info like this

FAIL
expected: (match? {:scheduled-for-datetime (roughly-same-time this-month)} (some-expr))
  actual: {:scheduled-for-datetime
 (mismatch
  (expected
   "similar-time 2022-08-30T16:36:25.588616447Z (+/- 5 seconds)")
  (actual #inst "2022-07-30T16:36:25.588Z"))}

or

(require '[matcher-combinators.matchers :as m])
(is (match? (m/via #(.toEpochMilli %)
                   (m/within-delta 100 (.toEpochMilli (Instant/now))))
            (some-expr)))

which gives mismatch info like this

FAIL
expected: (match? (m/via (fn* [p1__9809#] (.toEpochMilli p1__9809#)) (m/within-delta 100 (.toEpochMilli (Instant/now)))) (some-expr))
  actual: {:expected "within-delta 1671014561060 (+/- 100)" :actual 1671014560660}