hy/tests/native_tests/core.hy

;; Copyright 2020 the authors.
;; This file is part of Hy, which is free software licensed under the Expat
;; license. See the LICENSE.

;;;; some simple helpers

(defn assert-true [x]
  (assert (= True x)))

(defn assert-false [x]
  (assert (= False x)))

(defn assert-equal [x y]
  (assert (= x y)))

(defn assert-none [x]
  (assert (is x None)))

(defn assert-requires-num [f]
  (for [x ["foo" [] None]]
    (try (f x)
         (except [TypeError] True)
         (else (assert False)))))

(defn test-coll? []
  "NATIVE: testing coll?"
  (assert-true (coll? [1 2 3]))
  (assert-true (coll? {"a" 1 "b" 2}))
  (assert-true (coll? (range 10)))
  (assert-false (coll? "abc"))
  (assert-false (coll? 1)))

(defn test-butlast []
  "NATIVE: testing butlast function"
  (assert-equal (list (butlast (range 10)))
                [0 1 2 3 4 5 6 7 8])
  (assert-equal (list (butlast [1]))
                [])
  (assert-equal (list (butlast []))
                [])
  ; with an infinite sequence
  (import itertools)
  (assert-equal (list (take 5 (butlast (itertools.count 10))))
                [10 11 12 13 14]))

(defn test-cycle []
  "NATIVE: testing cycle"
  (assert-equal (list (cycle [])) [])
  (assert-equal (list (take 7 (cycle [1 2 3]))) [1 2 3 1 2 3 1])
  (assert-equal (list (take 2 (cycle [1 2 3]))) [1 2])
  (assert-equal (list (take 4 (cycle [1 None 3]))) [1 None 3 1]))

(defn test-dec []
  "NATIVE: testing the dec function"
  (assert-equal 0 (dec 1))
  (assert-equal -1 (dec 0))
  (assert-equal 0 (dec (dec 2)))
  (assert-requires-num dec))

(defn test-setv []
  "NATIVE: testing setv mutation"
  (setv x 1)
  (setv y 1)
  (assert-equal x y)
  (setv y 12)
  (setv x y)
  (assert-equal x 12)
  (assert-equal y 12)
  (setv y (fn [x] 9))
  (setv x y)
  (assert-equal (x y) 9)
  (assert-equal (y x) 9)
  (try (do (setv a.b 1) (assert False))
       (except [e [NameError]] (assert (in "name 'a' is not defined" (str e)))))
  (try (do (setv b.a (fn [x] x)) (assert False))
       (except [e [NameError]] (assert (in "name 'b' is not defined" (str e)))))
  (import itertools)
  (setv foopermutations (fn [x] (itertools.permutations x)))
  (setv p (set [(, 1 3 2) (, 3 2 1) (, 2 1 3) (, 3 1 2) (, 1 2 3) (, 2 3 1)]))
  (assert-equal (set (itertools.permutations [1 2 3])) p)
  (assert-equal (set (foopermutations [3 1 2])) p)
  (setv permutations- itertools.permutations)
  (setv itertools.permutations (fn [x] 9))
  (assert-equal (itertools.permutations p) 9)
  (assert-equal (foopermutations foopermutations) 9)
  (setv itertools.permutations permutations-)
  (assert-equal (set (itertools.permutations [2 1 3])) p)
  (assert-equal (set (foopermutations [2 3 1])) p))

(defn test-distinct []
  "NATIVE: testing the distinct function"
  (setv res (list (distinct [ 1 2 3 4 3 5 2 ])))
  (assert-equal res [1 2 3 4 5])
  ;; distinct of an empty list should be []
  (setv res (list (distinct [])))
  (assert-equal res [])
  ;; now with an iter
  (setv test_iter (iter [1 2 3 4 3 5 2]))
  (setv res (list (distinct test_iter)))
  (assert-equal res [1 2 3 4 5])
  ; make sure we can handle None in the list
  (setv res (list (distinct [1 2 3 2 5 None 3 4 None])))
  (assert-equal res [1 2 3 5 None 4]))

(defn test-drop []
  "NATIVE: testing drop function"
  (setv res (list (drop 2 [1 2 3 4 5])))
  (assert-equal res [3 4 5])
  (setv res (list (drop 3 (iter [1 2 3 4 5]))))
  (assert-equal res [4 5])
  (setv res (list (drop 3 (iter [1 2 3 None 4 5]))))
  (assert-equal res [None 4 5])
  (setv res (list (drop 0 [1 2 3 4 5])))
  (assert-equal res [1 2 3 4 5])
  (try (do (list (drop -1 [1 2 3 4 5])) (assert False))
       (except [e [ValueError]] None))
  (setv res (list (drop 6 (iter [1 2 3 4 5]))))
  (assert-equal res [])
  (setv res (list (take 5 (drop 2 (iterate inc 0)))))
  (assert-equal res [2 3 4 5 6]))

(defn test-drop-last []
  "NATIVE: testing drop-last function"
  (assert-equal (list (drop-last 5 (range 10 20)))
                [10 11 12 13 14])
  (assert-equal (list (drop-last 0 (range 5)))
                [0 1 2 3 4])
  (assert-equal (list (drop-last 100 (range 100)))
                [])
  ; with an infinite sequence
  (import itertools)
  (assert-equal (list (take 5 (drop-last 100 (itertools.count 10))))
                [10 11 12 13 14]))

(defn test-drop-while []
  "NATIVE: testing drop-while function"
  (setv res (list (drop-while even? [2 4 7 8 9])))
  (assert (= res [7 8 9]))
  (setv res (list (drop-while pos? [2 4 7 8 9])))
  (assert (= res []))
  (setv res (list (drop-while numeric? [1 2 3 None "a"])))
  (assert (= res [None "a"])))

(defn test-empty? []
  "NATIVE: testing the empty? function"
  (assert-true (empty? ""))
  (assert-false (empty? "None"))
  (assert-true (empty? (,)))
  (assert-false (empty? (, None)))
  (assert-true (empty? []))
  (assert-false (empty? [None]))
  (assert-true (empty? {}))
  (assert-false (empty? {"a" None}))
  (assert-true (empty? (set)))
  (assert-false (empty? (set [None]))))

(defn test-even []
  "NATIVE: testing the even? function"
  (assert-true (even? -2))
  (assert-false (even? 1))
  (assert-true (even? 0))
  (assert-requires-num even?))

(defn test-every? []
  "NATIVE: testing the every? function"
  (assert-true (every? even? [2 4 6]))
  (assert-false (every? even? [1 3 5]))
  (assert-false (every? even? [2 4 5]))
  (assert-true (every? even? [])))

(setv globalvar 1)
(defn test-exec []
  (setv localvar 1)
  (setv code "
result['localvar in locals'] = 'localvar' in locals()
result['localvar in globals'] = 'localvar' in globals()
result['globalvar in locals'] = 'globalvar' in locals()
result['globalvar in globals'] = 'globalvar' in globals()
result['x in locals'] = 'x' in locals()
result['x in globals'] = 'x' in globals()
result['y in locals'] = 'y' in locals()
result['y in globals'] = 'y' in globals()")

  (setv result {})
  (exec code)
  (assert-true (get result "localvar in locals"))
  (assert-false (get result "localvar in globals"))
  (assert-false (get result "globalvar in locals"))
  (assert-true (get result "globalvar in globals"))
  (assert-false (or
    (get result "x in locals") (get result "x in globals")
    (get result "y in locals") (get result "y in globals")))

  (setv result {})
  (exec code {"x" 1 "result" result})
  (assert-false (or
    (get result "localvar in locals") (get result "localvar in globals")
    (get result "globalvar in locals") (get result "globalvar in globals")))
  (assert-true (and
    (get result "x in locals") (get result "x in globals")))
  (assert-false (or
    (get result "y in locals") (get result "y in globals")))

  (setv result {})
  (exec code {"x" 1 "result" result} {"y" 1})
  (assert-false (or
    (get result "localvar in locals") (get result "localvar in globals")
    (get result "globalvar in locals") (get result "globalvar in globals")))
  (assert-false (get result "x in locals"))
  (assert-true (get result "x in globals"))
  (assert-true (get result "y in locals"))
  (assert-false (get result "y in globals")))

(defn test-filter []
  "NATIVE: testing the filter function"
  (setv res (list (filter pos? [ 1 2 3 -4 5])))
  (assert-equal res [ 1 2 3 5 ])
  ;; test with iter
  (setv res (list (filter pos? (iter [ 1 2 3 -4 5 -6]))))
  (assert-equal res [ 1 2 3 5])
  (setv res (list (filter neg? [ -1 -4 5 3 4])))
  (assert-false (= res [1 2]))
  ;; test with empty list
  (setv res (list (filter neg? [])))
  (assert-equal res [])
  ;; test with None in the list
  (setv res (list (filter even? (filter numeric? [1 2 None 3 4 None 4 6]))))
  (assert-equal res [2 4 4 6])
  (setv res (list (filter none? [1 2 None 3 4 None 4 6])))
  (assert-equal res [None None]))

(defn test-flatten []
  "NATIVE: testing the flatten function"
  (setv res (flatten [1 2 [3 4] 5]))
  (assert-equal res [1 2 3 4 5])
  (setv res (flatten ["foo" (, 1 2) [1 [2 3] 4] "bar"]))
  (assert-equal res ["foo" 1 2 1 2 3 4 "bar"])
  (setv res (flatten [1]))
  (assert-equal res [1])
  (setv res (flatten []))
  (assert-equal res [])
  (setv res (flatten (, 1)))
  (assert-equal res [1])
  ;; test with None
  (setv res (flatten (, 1 (, None 3))))
  (assert-equal res [1 None 3])
  (try (flatten "foo")
       (except [e [TypeError]] (assert (in "not a collection" (str e)))))
  (try (flatten 12.34)
       (except [e [TypeError]] (assert (in "not a collection" (str e))))))

(defn test-float? []
  "NATIVE: testing the float? function"
  (assert-true (float? 4.2))
  (assert-false (float? 0))
  (assert-false (float? -3))
  (assert-true (float? -3.2))
  (assert-false (float? "foo")))

(defn test-symbol? []
  "NATIVE: testing the symbol? function"
  (assert-false (symbol? "hello"))
  (assert-false (symbol? [1 2 3]))
  (assert-false (symbol? '[a b c]))
  (assert-true (symbol? 'im-symbol))
  (assert-false (symbol? (name 'im-symbol))))

(defn test-list? []
  "NATIVE: testing the list? function"
  (assert-false (list? "hello"))
  (assert-true (list? [1 2 3])))

(defn test-tuple? []
  "NATIVE: testing the tuple? function"
  (assert-false (tuple? [4 5]))
  (assert-true (tuple? (, 4 5))))

(defn test-gensym []
  "NATIVE: testing the gensym function"
  (import [hy.models [HySymbol]])
  (setv s1 (gensym))
  (assert (isinstance s1 HySymbol))
  (assert (= 0 (.find s1 "_G\uffff")))
  (setv s2 (gensym "xx"))
  (setv s3 (gensym "xx"))
  (assert (= 0 (.find s2 "_xx\uffff")))
  (assert (not (= s2 s3)))
  (assert (not (= (str s2) (str s3)))))

(defn test-identity []
  "NATIVE: testing the identity function"
  (assert (= 4 (identity 4)))
  (assert (= "hy" (identity "hy")))
  (assert (= [1 2] (identity [1 2]))))

(defn test-inc []
  "NATIVE: testing the inc function"
  (assert-equal 3 (inc 2))
  (assert-equal 0 (inc -1))
  (assert-requires-num inc)

  (defclass X [object]
    (defn __add__ [self other] (.format "__add__ got {}" other)))
  (assert-equal (inc (X)) "__add__ got 1"))

(defn test-instance []
  "NATIVE: testing instance? function"
  (defclass Foo [object])
  (defclass Foo2 [object])
  (defclass Foo3 [Foo])
  (setv foo (Foo))
  (setv foo3 (Foo3))
  (assert-true (instance? Foo foo))
  (assert-false (instance? Foo2 foo))
  (assert-true (instance? Foo foo3))
  (assert-true (instance? float 1.0))
  (assert-true (instance? int (int  3)))
  (assert-true (instance? str (str "hello"))))

(defn test-integer? []
  "NATIVE: testing the integer? function"
  (assert-true (integer? 0))
  (assert-true (integer? 3))
  (assert-true (integer? -3))
  (assert-true (integer? (int "-3")))
  (assert-true (integer? (int 3)))
  (assert-false (integer? 4.2))
  (assert-false (integer? None))
  (assert-false (integer? "foo")))

(defn test-integer-char? []
  "NATIVE: testing the integer-char? function"
  (assert-true (integer-char? "1"))
  (assert-true (integer-char? "-1"))
  (assert-true (integer-char? (str (int 300))))
  (assert-false (integer-char? "foo"))
  (assert-false (integer-char? None)))

(defn test-interleave []
  "NATIVE: testing the interleave function"
  ;; with more than 2 sequences
  (assert-equal (list (take 9 (interleave (range 10)
                                          (range 10 20)
                                          (range 20 30))))
                [0 10 20 1 11 21 2 12 22])
  ;; with sequences of different length
  (assert-equal (list (interleave (range 1000000)
                                  (range 0 -3 -1)))
                [0 0 1 -1 2 -2])
  ;; with infinite sequences
  (import itertools)
  (assert-equal (list (take 10 (interleave (itertools.count)
                                           (itertools.count 100))))
                [0 100 1 101 2 102 3 103 4 104]))

(defn test-interpose []
  "NATIVE: testing the interpose function"
  ;; with a list
  (assert-equal (list (interpose "!" ["a" "b" "c"]))
                ["a" "!" "b" "!" "c"])
  ;; with an infinite sequence
  (import itertools)
  (assert-equal (list (take 7 (interpose -1 (itertools.count))))
                [0 -1 1 -1 2 -1 3]))

(defn test-iterable []
  "NATIVE: testing iterable? function"
  ;; should work for a string
  (setv s (str "abcde"))
  (assert-true (iterable? s))
  ;; should work for unicode
  (setv u "hello")
  (assert-true (iterable? u))
  (assert-true (iterable? (iter u)))
  ;; should work for a list
  (setv l [1 2 3 4])
  (assert-true (iterable? l))
  (assert-true (iterable? (iter l)))
  ;; should work for a dict
  (setv d {:a 1 :b 2 :c 3})
  (assert-true (iterable? d))
  ;; should work for a tuple?
  (setv t (, 1 2 3 4))
  (assert-true (iterable? t))
  ;; should work for a generator
  (assert-true (iterable? (repeat 3)))
  ;; shouldn't work for an int
  (assert-false (iterable? 5)))

(defn test-iterate []
  "NATIVE: testing the iterate function"
  (setv res (list (take 5 (iterate inc 5))))
  (assert-equal res [5 6 7 8 9])
  (setv res (list (take 3 (iterate (fn [x] (* x x)) 5))))
  (assert-equal res [5 25 625])
  (setv f (take 4 (iterate inc 5)))
  (assert-equal (list f) [5 6 7 8]))

(defn test-iterator []
  "NATIVE: testing iterator? function"
  ;; should not work for a list
  (setv l [1 2 3 4])
  (assert-false (iterator? l))
  ;; should work for an iter over a list
  (setv i (iter [1 2 3 4]))
  (assert-true (iterator? i))
  ;; should not work for a dict
  (setv d {:a 1 :b 2 :c 3})
  (assert-false (iterator? d))
  ;; should not work for a tuple?
  (setv t (, 1 2 3 4))
  (assert-false (iterator? t))
  ;; should work for a generator
  (assert-true (iterator? (repeat 3)))
  ;; should not work for an int
  (assert-false (iterator? 5)))

(defn test-last []
  "NATIVE: testing the last function"
  (assert-equal (last [1 2 3 4]) 4)
  (assert-equal (last [5]) 5))
  (import itertools)
  (assert-equal (last (take 5 (itertools.count 10))) 14)

(defn test-neg []
  "NATIVE: testing the neg? function"
  (assert-true (neg? -2))
  (assert-false (neg? 1))
  (assert-false (neg? 0))
  (assert-requires-num neg?))

(defn test-zero []
  "NATIVE: testing the zero? function"
  (assert-false (zero? -2))
  (assert-false (zero? 1))
  (assert-true (zero? 0)))

(defn test-none []
  "NATIVE: testing for `is None`"
  (assert-true (none? None))
  (setv f None)
  (assert-true (none? f))
  (assert-false (none? 0))
  (assert-false (none? "")))

(defn test-nth []
  "NATIVE: testing the nth function"
  (assert-equal 2 (nth [1 2 4 7] 1))
  (assert-equal 7 (nth [1 2 4 7] 3))
  (assert-none (nth [1 2 4 7] 5))
  (assert-equal (nth [1 2 4 7] 5 "some default value")
                "some default value")  ; with default specified
  (try (do (nth [1 2 4 7] -1) (assert False))
       (except [e [ValueError]] None))
  ;; now for iterators
  (assert-equal 2 (nth (iter [1 2 4 7]) 1))
  (assert-equal 7 (nth (iter [1 2 4 7]) 3))
  (assert-none (nth (iter [1 2 4 7]) 5))
  (assert-equal (nth (iter [1 2 4 7]) 5 "some default value")
                "some default value")  ; with default specified
  (try (do (nth (iter [1 2 4 7]) -1) (assert False))
       (except [e [ValueError]] None))
  (assert-equal 5 (nth (take 3 (drop 2 [1 2 3 4 5 6])) 2)))

(defn test-numeric? []
  "NATIVE: testing the numeric? function"
  (assert-true (numeric? 1))
  (assert-true (numeric? 3.4))
  (assert-true (numeric? 0.0))
  (assert-true (numeric? -1.45))
  (assert-false (numeric? "Foo"))
  (assert-false (numeric? None)))

(defn test-odd []
  "NATIVE: testing the odd? function"
  (assert-true (odd? -3))
  (assert-true (odd? 1))
  (assert-false (odd? 0))
  (assert-requires-num odd?))

(defn test-parse-args []
  "NATIVE: testing the parse-args function"
  ; https://github.com/hylang/hy/issues/1875
  (setv parsed-args (parse-args [["strings" :nargs "+" :help "Strings"]
                                 ["-n" :action "append" :type int :help "Numbers" "--numbers"]]
                                ["a" "b" "-n" "1" "--numbers" "2"]
                                :description "Parse strings and numbers from args"))
  (assert-equal parsed-args.strings ["a" "b"])
  (assert-equal parsed-args.numbers [1 2]))

(defn test-partition []
  "NATIVE: testing the partition function"
  (setv ten (range 10))
  ;; no remainder
  (assert-equal (list (partition ten 3))
                [(, 0 1 2) (, 3 4 5) (, 6 7 8)])
  ;; pair by default
  (assert-equal (list (partition ten))
                [(, 0 1) (, 2 3) (, 4 5) (, 6 7) (, 8 9)])
  ;; length 1 is valid
  (assert-equal (list (partition ten 1))
                [(, 0) (, 1) (, 2) (, 3) (, 4) (, 5) (, 6) (, 7) (, 8) (, 9)])
  ;; length 0 returns an empty sequence
  (assert-equal (list (partition ten 0)) [])
  ;; negative length raises ValueError
  (try (do (partition ten -1) (assert False))
       (except [ValueError]))
  ;; keep remainder with a fillvalue
  (assert-equal (list (partition ten 3 :fillvalue "x"))
                [(, 0 1 2) (, 3 4 5) (, 6 7 8) (, 9 "x" "x")])
  ;; skip elements with step > n
  (assert-equal (list (partition ten 2 3))
                [(, 0 1) (, 3 4) (, 6 7)])
  ;; overlap with step < n
  (assert-equal (list (partition (range 5) 2 1))
                [(, 0 1) (, 1 2) (, 2 3) (, 3 4)])
  ;; tee the input as necessary
  ;; https://github.com/hylang/hy/issues/1237
  (assert-equal (list (take 4 (partition (cycle [1 2 3]) 3)))
                [(, 1 2 3) (, 1 2 3) (, 1 2 3) (, 1 2 3)])
  (assert-equal (list (partition (iter (range 10))))
                [(, 0 1) (, 2 3) (, 4 5) (, 6 7) (, 8 9)]))

(defn test-pos []
  "NATIVE: testing the pos? function"
  (assert-true (pos? 2))
  (assert-false (pos? -1))
  (assert-false (pos? 0))
  (assert-requires-num pos?))

(defn test-remove []
  "NATIVE: testing the remove function"
  (setv r (list (remove odd? [1 2 3 4 5 6 7])))
  (assert-equal r [2 4 6])
  (assert-equal (list (remove even? [1 2 3 4 5])) [1 3 5])
  (assert-equal (list (remove neg? [1 2 3 4 5])) [1 2 3 4 5])
  (assert-equal (list (remove pos? [1 2 3 4 5])) [])
  ;; deal with embedded None
  (assert-equal (list (remove (fn [x] (not (numeric? x))) [1 2 None 3 None 4])) [1 2 3 4]))

(defn test-repeat []
  "NATIVE: testing repeat"
  (setv r (repeat 10))
  (assert-equal (list (take 5 r)) [10 10 10 10 10])
  (assert-equal (list (take 4 r)) [10 10 10 10])
  (setv r (repeat 10 3))
  (assert-equal (list r) [10 10 10]))

(defn test-repeatedly []
  "NATIVE: testing repeatedly"
  (setv r (repeatedly (fn [] (inc 4))))
  (assert-equal (list (take 5 r)) [5 5 5 5 5])
  (assert-equal (list (take 4 r)) [5 5 5 5])
  (assert-equal (list (take 6 r)) [5 5 5 5 5 5]))

(defn test-second []
  "NATIVE: testing second"
  (assert-equal 2 (second [1 2]))
  (assert-equal 3 (second [2 3 4])))

(defn test-some []
  "NATIVE: testing the some function"
  (assert-true (some even? [2 4 6]))
  (assert-none (some even? [1 3 5]))
  (assert-true (some even? [1 2 3]))
  (assert-none (some even? []))
  ; 0, "" (empty string) and [] (empty list) are all logical false
  (assert-none (some identity [0 "" []]))
  ; non-empty string is logical true
  (assert-equal (some identity [0 "this string is non-empty" []])
                "this string is non-empty")
  ; None if collection is empty
  (assert-none (some even? [])))

(defn test-string? []
  "NATIVE: testing string?"
  (assert-true (string? "foo"))
  (assert-true (string? ""))
  (assert-false (string? 5.3))
  (assert-true (string? (str 5.3)))
  (assert-false (string? None)))

(defn test-take []
  "NATIVE: testing the take function"
  (setv res (list (take 3 [1 2 3 4 5])))
  (assert-equal res [1 2 3])
  (setv res (list (take 4 (repeat "s"))))
  (assert-equal res ["s" "s" "s" "s"])
  (setv res (list (take 0 (repeat "s"))))
  (assert-equal res [])
  (try (do (list (take -1 (repeat "s"))) (assert False))
       (except [e [ValueError]] None))
  (setv res (list (take 6 [1 2 None 4])))
  (assert-equal res [1 2 None 4]))

(defn test-take-nth []
  "NATIVE: testing the take-nth function"
  (setv res (list (take-nth 2 [1 2 3 4 5 6 7])))
  (assert-equal res [1 3 5 7])
  (setv res (list (take-nth 3 [1 2 3 4 5 6 7])))
  (assert-equal res [1 4 7])
  (setv res (list (take-nth 4 [1 2 3 4 5 6 7])))
  (assert-equal res [1 5])
  (setv res (list (take-nth 5 [1 2 3 4 5 6 7])))
  (assert-equal res [1 6])
  (setv res (list (take-nth 6 [1 2 3 4 5 6 7])))
  (assert-equal res [1 7])
  (setv res (list (take-nth 7 [1 2 3 4 5 6 7])))
  (assert-equal res [1])
  ;; what if there are None's in list
  (setv res (list (take-nth 2 [1 2 3 None 5 6])))
  (assert-equal res [1 3 5])
  (setv res (list (take-nth 3 [1 2 3 None 5 6])))
  (assert-equal res [1 None])
  ;; using 0 should raise ValueError
  (setv passed False)
  (try
   (setv res (list (take-nth 0 [1 2 3 4 5 6 7])))
   (except [ValueError] (setv passed True)))
  (assert passed))

(defn test-take-while []
  "NATIVE: testing the take-while function"
  (setv res (list (take-while pos? [ 1 2 3 -4 5])))
  (assert-equal res [1 2 3])
  (setv res (list (take-while neg? [ -1 -4 5 3 4])))
  (assert-false (= res [1 2]))
  (setv res (list (take-while none? [None None 1 2 3])))
  (assert-equal res [None None])
  (setv res (list (take-while (fn [x] (not (none? x))) [1 2 3 4 None 5 6 None 7])))
  (assert-equal res [1 2 3 4]))

(defn test-doto []
  "NATIVE: testing doto macro"
  (setv collection [])
  (doto collection (.append 1) (.append 2) (.append 3))
  (assert-equal collection [1 2 3])
  (setv res (doto (set) (.add 2) (.add 1)))
  (assert-equal res (set [1 2]))
  (setv res (doto [] (.append 1) (.append 2) .reverse))
  (assert-equal res [2 1]))

(defn test-is-keyword []
  "NATIVE: testing the keyword? function"
  (assert (keyword? ':bar))
  (assert (keyword? ':baz))
  (setv x :bar)
  (assert (keyword? x))
  (assert (not (keyword? "foo")))
  (assert (not (keyword? ":foo")))
  (assert (not (keyword? 1)))
  (assert (not (keyword? None))))

(defn test-import-init-hy []
  "NATIVE: testing import of __init__.hy"
  (import tests.resources.bin)
  (assert (in "_null_fn_for_import_test" (dir tests.resources.bin))))

(defn test-accumulate []
  "NATIVE: testing the accumulate function"
  (assert-equal (list (accumulate ["a" "b" "c"]))
                ["a" "ab" "abc"])
  (assert-equal (list (accumulate [1 2 3 4 5]))
                [1 3 6 10 15])
  (assert-equal (list (accumulate [1 -2 -3 -4 -5] -))
                [1 3 6 10 15]))

(defn test-complement []
  "NATIVE: test complement"
  (setv helper (complement identity))

  (assert-true (helper False))
  (assert-false (helper True)))

(defn test-constantly []
  "NATIVE: test constantly"
  (setv helper (constantly 42))

  (assert-true (= (helper) 42))
  (assert-true (= (helper 1 2 3) 42))
  (assert-true (= (helper 1 2 :foo 3) 42)))

(defn test-comp []
  "NATIVE: test comp"
  (assert-true ((comp odd? inc second) [1 2 3 4 5]))
  (assert-true (= 1 ((comp first) [1 2 3])))
  (assert-true ((comp even? inc +) 1 2 3 4 5))
  (assert-true (= 5 ((comp) 5)))
  (assert (is (comp) identity)))

(defn test-juxt []
  "NATIVE: test juxt"
  (assert-equal ((juxt min max sum) [1 2 3 4 5 6])
                [1 6 21])
  (assert-equal ((juxt identity) 42)
                [42]))

(defn test-comment []
  (assert-none (comment <h1>This is merely a comment.</h1>
                        <p> Move along. (Nothing to see here.)</p>)))

(defn test-doc [capsys]
  (doc doc)
  (setv out_err (.readouterr capsys))
  (assert (.startswith (.strip (first out_err))
            "Help on function doc in module hy.core.macros:"))
  (assert (empty? (second out_err))))