我的Clojure规格如下：
(spec/def ::global-id string?)
(spec/def ::part-of string?)
(spec/def ::type string?)
(spec/def ::value string?)
(spec/def ::name string?)
(spec/def ::text string?)
(spec/def ::date (spec/nilable (spec/and string? #(re-matches #"^\d{4}-\d{2}-\d{2}$" %))))
(spec/def ::interaction-name string?)
(spec/def ::center (spec/coll-of string? :kind vector? :count 2))
(spec/def ::context- (spec/keys :req [::global-id ::type]
:opt [::part-of ::center]))
(spec/def ::contexts (spec/coll-of ::context-))
(spec/def ::datasource string?)
(spec/def ::datasource- (spec/nilable (spec/keys :req [::global-id ::name])))
(spec/def ::datasources (spec/coll-of ::datasource-))
(spec/def ::location string?)
(spec/def ::location-meaning- (spec/keys :req [::global-id ::location ::contexts ::type]))
(spec/def ::location-meanings (spec/coll-of ::location-meaning-))
(spec/def ::context string?)
(spec/def ::context-association-type string?)
(spec/def ::context-association-name string?)
(spec/def ::priority string?)
(spec/def ::has-context- (spec/keys :req [::context ::context-association-type ::context-association-name ::priority]))
(spec/def ::has-contexts (spec/coll-of ::has-context-))
(spec/def ::fact- (spec/keys :req [::global-id ::type ::name ::value]))
(spec/def ::facts (spec/coll-of ::fact-))
(spec/def ::attribute- (spec/keys :req [::name ::type ::value]))
(spec/def ::attributes (spec/coll-of ::attribute-))
(spec/def ::fulltext (spec/keys :req [::global-id ::text]))
(spec/def ::feature- (spec/keys :req [::global-id ::date ::location-meanings ::has-contexts ::facts ::attributes ::interaction-name]
:opt [::fulltext]))
(spec/def ::features (spec/coll-of ::feature-))
(spec/def ::attribute- (spec/keys :req [::name ::type ::value]))
(spec/def ::attributes (spec/coll-of ::attribute-))
(spec/def ::ioi-slice string?)
(spec/def ::ioi- (spec/keys :req [::global-id ::type ::datasource ::features ::attributes ::ioi-slice]))
(spec/def ::iois (spec/coll-of ::ioi-))
(spec/def ::data (spec/keys :req [::contexts ::datasources ::iois]))
(spec/def ::data- ::data)
但是它无法生成具有以下内容的样本：
(spec/fdef data->graph
:args (spec/cat :data ::xml-spec/data-))
(println (stest/check `data->graph))
然后它将无法生成，并带有以下异常：
Couldn't satisfy such-that predicate after 100 tries.
使用stest/check自动生成规范非常方便，但是如何除了规范之外也有生成器？
答案 0 :(得分：7)
当您从规范生成数据时看到错误Couldn't satisfy such-that predicate after 100 tries.时，常见的原因是s/and规范，因为规范仅基于 first <为<{1}}规范构建生成器/ em>内部规格。
此规范似乎最有可能引起这种情况，因为s/and中的第一个内部规范/谓词为s/and，而以下谓词为正则表达式：
string?如果您对(s/def ::date (s/nilable (s/and string? #(re-matches #"^\d{4}-\d{2}-\d{2}$" %))))
生成器进行采样，则会看到它生成的内容不太可能与您的正则表达式匹配：
string? test.check将尝试（默认情况下为100次）获取满足(gen/sample (s/gen string?))
=> ("" "" "X" "" "" "hT9" "7x97" "S" "9" "1Z")
条件的值，然后引发您看到的异常（如果不满足）。
您可以通过多种方式为此规范实现自定义生成器。这是一个test.check生成器，它将创建ISO本地日期字符串：
such-that这种方法获取有效时期的范围，用它来控制(def gen-local-date-str
(let [day-range (.range (ChronoField/EPOCH_DAY))
day-min (.getMinimum day-range)
day-max (.getMaximum day-range)]
(gen/fmap #(str (LocalDate/ofEpochDay %))
(gen/large-integer* {:min day-min :max day-max}))))
生成器的范围，然后控制生成的整数的large-integer* fmap的范围。
LocalDate/ofEpochDay这从默认的(def gen-local-date-str
(gen/fmap #(-> (Instant/ofEpochMilli %)
(LocalDateTime/ofInstant ZoneOffset/UTC)
(.toLocalDate)
(str))
gen/large-integer))
生成器开始，并使用large-integer提供一个函数，该函数从生成的整数创建fmap，将其转换为java.time.Instant，然后进行转换恰好与您的日期字符串格式匹配的字符串。 （在Java 9及更高版本上，java.time.LocalDate稍微简单一些。）
另一种方法可能使用test.chuck的regex-based string generator或其他日期类/格式器。请注意，我的两个示例都将生成-9999 / + 9999之前/之后的年份，这与您的java.time.LocalDate/ofInstant年正则表达式不匹配，但是生成器应该经常产生令人满意的值，因此对于您的用例。生成日期值的方法有很多！
\d{4}然后，您可以使用(gen/sample gen-local-date-str)
=>
("1969-12-31"
"1970-01-01"
"1970-01-01"
...)
将此生成器与您的规范相关联：
s/with-gen如果您不想将定制生成器直接绑定到规范定义，还可以为带有 overrides 映射的某些规范函数提供“独立”定制生成器：
(s/def ::date
(s/nilable
(s/with-gen
(s/and string? #(re-matches #"^\d{4}-\d{2}-\d{2}$" %))
(constantly gen-local-date-str))))
(gen/sample (s/gen ::date))
=>
("1969-12-31"
nil ;; note that it also makes nils b/c it's wrapped in s/nilable
"1970-01-01"
...)
使用此规范和生成器，我可以生成较大的(gen/sample (s/gen ::data {::date (constantly gen-local-date-str)}))
规范，尽管由于某些集合规范，输出非常很大。您还可以使用规范中的::data选项控制生成过程中的大小。