cljs.spec.alpha

previously cljs.spec

& - macro
(& re & preds)
takes a regex op re, and predicates. Returns a regex-op that consumes
input as per re but subjects the resulting value to the
conjunction of the predicates, and any conforming they might perform.

* - macro
(* pred-form)
Returns a regex op that matches zero or more values matching
pred. Produces a vector of matches iff there is at least one match

*coll-check-limit* - dynamic var

*coll-error-limit* - dynamic var

*compile-asserts* - dynamic var
If true, compiler will enable spec asserts, which are then
subject to runtime control via check-asserts? If false, compiler
will eliminate all spec assert overhead. See 'assert'.
Initially set to the negation of the ':elide-asserts' compiler option.
Defaults to true.

*explain-out* - dynamic var

*fspec-iterations* - dynamic var

*recursion-limit* - dynamic var

+ - macro
(+ pred-form)
Returns a regex op that matches one or more values matching
pred. Produces a vector of matches

? - macro
(? pred-form)
Returns a regex op that matches zero or one value matching
pred. Produces a single value (not a collection) if matched.

MAX_INT - var

abbrev - function
(abbrev form)

alt - macro
(alt & key-pred-forms)
Takes key+pred pairs, e.g.

(s/alt :even even? :small #(< % 42))

Returns a regex op that returns a map entry containing the key of the
first matching pred and the corresponding value. Thus the
'key' and 'val' functions can be used to refer generically to the
components of the tagged return.

and - macro
(and & pred-forms)
Takes predicate/spec-forms, e.g.

(s/and even? #(< % 42))

Returns a spec that returns the conformed value. Successive
conformed values propagate through rest of predicates.

assert - macro
(assert spec x)
spec-checking assert expression. Returns x if x is valid? according
to spec, else throws an error with explain-data plus ::failure of
:assertion-failed.
Can be disabled at either compile time or runtime:
If *compile-asserts* is false at compile time, compiles to x. Defaults
to the negation value of the ':elide-asserts' compiler option, or true if
not set.
If (check-asserts?) is false at runtime, always returns x. Defaults to
value of 'cljs.spec.alpha/*runtime-asserts*', or false if not set. You can
toggle check-asserts? with (check-asserts bool).

assert* - function
(assert* spec x)
Do not call this directly, use 'assert'.

cat - macro
(cat & key-pred-forms)
Takes key+pred pairs, e.g.

(s/cat :e even? :o odd?)

Returns a regex op that matches (all) values in sequence, returning a map
containing the keys of each pred and the corresponding value.

check-asserts - function
(check-asserts flag)
Enable or disable spec asserts that have been compiled
with '*compile-asserts*' true.  See 'assert'.
Initially set to boolean value of cljs.spec.alpha/*runtime-asserts*.
Defaults to false.

check-asserts? - function
(check-asserts?)
Returns the value set by check-asserts.

coll-of - macro
(coll-of pred & opts)
Returns a spec for a collection of items satisfying pred. Unlike
generator will fill an empty init-coll.

Same options as 'every'. conform will produce a collection
corresponding to :into if supplied, else will match the input collection,
avoiding rebuilding when possible.

Same options as 'every'.

See also - every, map-of

conform - function
(conform spec x)
Given a spec and a value, returns :cljs.spec.alpha/invalid if value does
not match spec, else the (possibly destructured) value.

conformer - macro
(conformer f)
(conformer f unf)
takes a predicate function with the semantics of conform i.e. it should return either a
(possibly converted) value or :cljs.spec.alpha/invalid, and returns a
spec that uses it as a predicate/conformer. Optionally takes a
second fn that does unform of result of first

def - macro
(def k spec-form)
Given a namespace-qualified keyword or resolveable symbol k, and a spec,
spec-name, predicate or regex-op makes an entry in the registry mapping k to
the spec

describe - function
(describe spec)
returns an abbreviated description of the spec as data

double-in - macro
(double-in & {:keys [infinite? NaN? min max], :or {infinite? true, NaN? true}, :as m})
Specs a 64-bit floating point number. Options:

 :infinite? - whether +/- infinity allowed (default true)
 :NaN?      - whether NaN allowed (default true)
 :min       - minimum value (inclusive, default none)
 :max       - maximum value (inclusive, default none)

every - macro
(every pred & {:keys [into kind count max-count min-count distinct gen-max gen-into gen], :as opts})
takes a pred and validates collection elements against that pred.

Note that 'every' does not do exhaustive checking, rather it samples
*coll-check-limit* elements. Nor (as a result) does it do any
conforming of elements. 'explain' will report at most *coll-error-limit*
problems.  Thus 'every' should be suitable for potentially large
collections.

Takes several kwargs options that further constrain the collection:

:kind - a pred/spec that the collection type must satisfy, e.g. vector?
        (default nil) Note that if :kind is specified and :into is
        not, this pred must generate in order for every to generate.
:count - specifies coll has exactly this count (default nil)
:min-count, :max-count - coll has count (<= min-count count max-count) (defaults nil)
:distinct - all the elements are distinct (default nil)

And additional args that control gen

:gen-max - the maximum coll size to generate (default 20)
:into - one of [], (), {}, #{} - the default collection to generate into
    (default same as :kind if supplied, else []

Optionally takes :gen generator-fn, which must be a fn of no args that
returns a test.check generator

See also - coll-of, every-kv

every-kv - macro
(every-kv kpred vpred & opts)
like 'every' but takes separate key and val preds and works on associative collections.

Same options as 'every', :into defaults to {}

See also - map-of

exercise - function
(exercise spec)
(exercise spec n)
(exercise spec n overrides)
generates a number (default 10) of values compatible with spec and maps conform over them,
returning a sequence of [val conformed-val] tuples. Optionally takes
a generator overrides map as per gen

exercise-fn - macro
(exercise-fn sym)
(exercise-fn sym n)
(exercise-fn sym n fspec)
exercises the fn named by sym (a symbol) by applying it to
n (default 10) generated samples of its args spec. When fspec is
supplied its arg spec is used, and sym-or-f can be a fn.  Returns a
sequence of tuples of [args ret]. 

explain - function
(explain spec x)
Given a spec and a value that fails to conform, prints an explanation to *out*.

explain-data - function
(explain-data spec x)
Given a spec and a value x which ought to conform, returns nil if x
conforms, else a map with at least the key ::problems whose value is
a collection of problem-maps, where problem-map has at least :path :pred and :val
keys describing the predicate and the value that failed at that
path.

explain-data* - function
(explain-data* spec path via in x)

explain-out - function
(explain-out ed)
Prints explanation data (per 'explain-data') to *out* using the printer in *explain-out*,
 by default explain-printer.

explain-printer - function
(explain-printer ed)
Default printer for explain-data. nil indicates a successful validation.

explain-str - function
(explain-str spec x)
Given a spec and a value that fails to conform, returns an explanation as a string.

fdef - macro
(fdef fn-sym & specs)
Takes a symbol naming a function, and one or more of the following:

:args A regex spec for the function arguments as they were a list to be
  passed to apply - in this way, a single spec can handle functions with
  multiple arities
:ret A spec for the function's return value
:fn A spec of the relationship between args and ret - the
  value passed is {:args conformed-args :ret conformed-ret} and is
  expected to contain predicates that relate those values

Qualifies fn-sym with resolve, or using *ns* if no resolution found.
Registers an fspec in the global registry, where it can be retrieved
by calling get-spec with the var or full-qualified symbol.

Once registered, function specs are included in doc, checked by
instrument, tested by the runner cljs.spec.test.alpha/run-tests, and (if
a macro) used to explain errors during macroexpansion.

Note that :fn specs require the presence of :args and :ret specs to
conform values, and so :fn specs will be ignored if :args or :ret
are missing.

Returns the qualified fn-sym.

For example, to register function specs for the symbol function:

(s/fdef cljs.core/symbol
  :args (s/alt :separate (s/cat :ns string? :n string?)
               :str string?
               :sym symbol?)
  :ret symbol?)

form - function
(form spec)
returns the spec as data

fspec - macro
(fspec & {:keys [args ret fn gen], :or {ret (quote cljs.core/any?)}})
takes :args :ret and (optional) :fn kwargs whose values are preds
and returns a spec whose conform/explain take a fn and validates it
using generative testing. The conformed value is always the fn itself.

See 'fdef' for a single operation that creates an fspec and
registers it, as well as a full description of :args, :ret and :fn

fspecs can generate functions that validate the arguments and
fabricate a return value compliant with the :ret spec, ignoring
the :fn spec if present.

Optionally takes :gen generator-fn, which must be a fn of no args
that returns a test.check generator.

gen - function
(gen spec)
(gen spec overrides)
Given a spec, returns the generator for it, or throws if none can
be constructed. Optionally an overrides map can be provided which
should map spec names or paths (vectors of keywords) to no-arg
generator-creating fns. These will be used instead of the generators at those
names/paths. Note that parent generator (in the spec or overrides
map) will supersede those of any subtrees. A generator for a regex
op must always return a sequential collection (i.e. a generator for
s/? should return either an empty sequence/vector or a
sequence/vector with one item in it)

get-spec - function
(get-spec k)
Returns spec registered for keyword/symbol/var k, or nil.

inst-in - macro
(inst-in start end)
Returns a spec that validates insts in the range from start
(inclusive) to end (exclusive).

inst-in-range? - function
(inst-in-range? start end inst)
Return true if inst at or after start and before end

int-in - macro
(int-in start end)
Returns a spec that validates fixed precision integers in the
range from start (inclusive) to end (exclusive).

int-in-range? - function
(int-in-range? start end val)
Return true if start <= val, val < end and val is a fixed
precision integer.

invalid? - function
(invalid? ret)
tests the validity of a conform return value

keys - macro
(keys & {:keys [req req-un opt opt-un gen]})
Creates and returns a map validating spec. :req and :opt are both
vectors of namespaced-qualified keywords. The validator will ensure
the :req keys are present. The :opt keys serve as documentation and
may be used by the generator.

The :req key vector supports 'and' and 'or' for key groups:

(s/keys :req [::x ::y (or ::secret (and ::user ::pwd))] :opt [::z])

There are also -un versions of :req and :opt. These allow
you to connect unqualified keys to specs.  In each case, fully
qualfied keywords are passed, which name the specs, but unqualified
keys (with the same name component) are expected and checked at
conform-time, and generated during gen:

(s/keys :req-un [:my.ns/x :my.ns/y])

The above says keys :x and :y are required, and will be validated
and generated by specs (if they exist) named :my.ns/x :my.ns/y
respectively.

In addition, the values of *all* namespace-qualified keys will be validated
(and possibly destructured) by any registered specs. Note: there is
no support for inline value specification, by design.

Optionally takes :gen generator-fn, which must be a fn of no args that
returns a test.check generator.

keys* - macro
(keys* & kspecs)
takes the same arguments as spec/keys and returns a regex op that matches sequences of key/values,
converts them into a map, and conforms that map with a corresponding
spec/keys call:

user=> (s/conform (s/keys :req-un [::a ::c]) {:a 1 :c 2})
{:a 1, :c 2}
user=> (s/conform (s/keys* :req-un [::a ::c]) [:a 1 :c 2])
{:a 1, :c 2}

the resulting regex op can be composed into a larger regex:

user=> (s/conform (s/cat :i1 integer? :m (s/keys* :req-un [::a ::c]) :i2 integer?) [42 :a 1 :c 2 :d 4 99])
{:i1 42, :m {:a 1, :c 2, :d 4}, :i2 99}

map-of - macro
(map-of kpred vpred & opts)
Returns a spec for a map whose keys satisfy kpred and vals satisfy
vpred. Unlike 'every-kv', map-of will exhaustively conform every
value.

Same options as 'every', :kind defaults to map?, with the addition of:

:conform-keys - conform keys as well as values (default false)

See also - every-kv

merge - macro
(merge & pred-forms)
Takes map-validating specs (e.g. 'keys' specs) and
returns a spec that returns a conformed map satisfying all of the
specs.  Successive conformed values propagate through rest of
predicates. Unlike 'and', merge can generate maps satisfying the
union of the predicates.

multi-spec - macro
(multi-spec mm retag)
Takes the name of a spec/predicate-returning multimethod and a
tag-restoring keyword or fn (retag).  Returns a spec that when
conforming or explaining data will pass it to the multimethod to get
an appropriate spec. You can e.g. use multi-spec to dynamically and
extensibly associate specs with 'tagged' data (i.e. data where one
of the fields indicates the shape of the rest of the structure).

(defmulti mspec :tag)

The methods should ignore their argument and return a predicate/spec:
(defmethod mspec :int [_] (s/keys :req-un [::tag ::i]))

retag is used during generation to retag generated values with
matching tags. retag can either be a keyword, at which key the
dispatch-tag will be assoc'ed, or a fn of generated value and
dispatch-tag that should return an appropriately retagged value.

Note that because the tags themselves comprise an open set,
the tag key spec cannot enumerate the values, but can e.g.
test for keyword?.

Note also that the dispatch values of the multimethod will be
included in the path, i.e. in reporting and gen overrides, even
though those values are not evident in the spec.

nilable - macro
(nilable pred)
returns a spec that accepts nil and values satisfiying pred

nonconforming - function
(nonconforming spec)
takes a spec and returns a spec that has the same properties except
'conform' returns the original (not the conformed) value. Note, will specize regex ops.

or - macro
(or & key-pred-forms)
Takes key+pred pairs, e.g.

(s/or :even even? :small #(< % 42))

Returns a destructuring spec that returns a map entry containing the
key of the first matching pred and the corresponding value. Thus the
'key' and 'val' functions can be used to refer generically to the
components of the tagged return.

regex? - function
(regex? x)
returns x if x is a (cljs.spec.alpha) regex op, else logical false

registry - function
(registry)
returns the registry map, prefer 'get-spec' to lookup a spec by name

registry-ref - var

spec - macro
(spec form & {:keys [gen]})
Takes a single predicate form, e.g. can be the name of a predicate,
like even?, or a fn literal like #(< % 42). Note that it is not
generally necessary to wrap predicates in spec when using the rest
of the spec macros, only to attach a unique generator

Can also be passed the result of one of the regex ops -
cat, alt, *, +, ?, in which case it will return a regex-conforming
spec, useful when nesting an independent regex.
---

Optionally takes :gen generator-fn, which must be a fn of no args that
returns a test.check generator.

Returns a spec.

spec? - function
(spec? x)
returns x if x is a spec object, else logical false

speced-vars - function
(speced-vars)

tuple - macro
(tuple & preds)
takes one or more preds and returns a spec for a tuple, a vector
where each element conforms to the corresponding pred. Each element
will be referred to in paths using its ordinal.

unform - function
(unform spec x)
Given a spec and a value created by or compliant with a call to
'conform' with the same spec, returns a value with all conform
 destructuring undone.

valid? - function
(valid? spec x)
(valid? spec x form)
Helper function that returns true when x is valid for spec.

with-gen - function
(with-gen spec gen-fn)
Takes a spec and a no-arg, generator-returning fn and returns a version of that spec that uses that generator

Types and Protocols


Spec - protocol

Specize - protocol