Returns current value of dynamic assertion data.

Takes a (fn pred [x]) => truthy, and >=1 vals.
Tests pred against each val,trapping errors.

If any pred test fails, throws a detailed `ExceptionInfo`.
Otherwise returns input val/s for convenient inline-use/binding.

Respects `*assert*`, so tests can be elided from production if desired
(meaning zero runtime cost).

Provides a small, simple, flexible feature subset to alternative tools like
clojure.spec, core.typed, prismatic/schema, etc.

Examples:

  (defn my-trim [x] (str/trim (have string? x)))

  ;; Attach arb optional info to violations using `:data`:
  (have string? x
    :data {:my-arbitrary-debug-info "foo"})

  ;; Assert inside collections using `:in`:
  (have string? :in ["foo" "bar"])

Regarding use within other macros:
  Due to CLJ-865, callsite info like line number of outer macro
  will be lost. See `keep-callsite` for workaround.

See also `have?`, `have!`.

Like `have` but ignores `*assert*` value (so can never be elided!).
Useful for important conditions in production (e.g. security checks).

Returns `true` on successful tests, and ignores `*assert*` value
(so can never be elided!).

**WARNING**: Do NOT use in `:pre`/`:post` conditions since those always
respect `*assert*`, contradicting the intention of the bang (`!`) here.

Like `have` but returns `true` on successful tests.
Handy for `:pre`/`:post` conditions. Compare:
  ((fn my-fn [] {:post [(have  nil? %)]} nil)) ; {:post [nil ]} FAILS
  ((fn my-fn [] {:post [(have? nil? %)]} nil)) ; {:post [true]} passes as intended

The long-standing CLJ-865 means that it's not possible for an inner
macro to access the `&form` metadata of a wrapping outer macro. This
means that wrapped macros lose calsite info, etc.

This util offers a workaround for macro authors:
  (defmacro inner [] (meta &form))
  (defmacro outer [] (keep-callsite `(inner)))
  (outer) => {:keys [line column ...]}

Sets the root (fn [data-map-delay]) called on invariant violations.

Executes body with dynamic assertion data bound to given value.
This data will be included in any violation errors thrown by body.