hy/tests/native_tests/py3_only_tests.hy

;; Copyright 2017 the authors.
;; This file is part of Hy, which is free software licensed under the Expat
;; license. See the LICENSE.

;; Tests where the emitted code relies on Python 3.
;; conftest.py skips this file when running on Python 2.


(defn test-exception-cause []
  (try (raise ValueError :from NameError)
  (except [e [ValueError]]
    (assert (= (type (. e __cause__)) NameError)))))


(defn test-kwonly []
  "NATIVE: test keyword-only arguments"
  ;; keyword-only with default works
  (defn kwonly-foo-default-false [&kwonly [foo False]] foo)
  (assert (= (kwonly-foo-default-false) False))
  (assert (= (kwonly-foo-default-false :foo True) True))
  ;; keyword-only without default ...
  (defn kwonly-foo-no-default [&kwonly foo] foo)
  (setv attempt-to-omit-default (try
                                (kwonly-foo-no-default)
                                (except [e [Exception]] e)))
  ;; works
  (assert (= (kwonly-foo-no-default :foo "quux") "quux"))
  ;; raises TypeError with appropriate message if not supplied
  (assert (isinstance attempt-to-omit-default TypeError))
  (assert (in "missing 1 required keyword-only argument: 'foo'"
              (. attempt-to-omit-default args [0])))
  ;; keyword-only with other arg types works
  (defn function-of-various-args [a b &rest args &kwonly foo &kwargs kwargs]
    (, a b args foo kwargs))
  (assert (= (function-of-various-args 1 2 3 4 :foo 5 :bar 6 :quux 7)
             (, 1 2 (, 3 4)  5 {"bar" 6 "quux" 7}))))


(defn test-extended-unpacking-1star-lvalues []
  (setv [x #*y] [1 2 3 4])
  (assert (= x 1))
  (assert (= y [2 3 4]))
  (setv [a #*b c] "ghijklmno")
  (assert (= a "g"))
  (assert (= b (list "hijklmn")))
  (assert (= c "o")))


(defn test-yield-from []
  "NATIVE: testing yield from"
  (defn yield-from-test []
    (for* [i (range 3)]
      (yield i))
    (yield-from [1 2 3]))
  (assert (= (list (yield-from-test)) [0 1 2 1 2 3])))


(defn test-yield-from-exception-handling []
  "NATIVE: Ensure exception handling in yield from works right"
  (defn yield-from-subgenerator-test []
    (yield 1)
    (yield 2)
    (yield 3)
    (assert 0))
  (defn yield-from-test []
    (for* [i (range 3)]
       (yield i))
    (try
     (yield-from (yield-from-subgenerator-test))
     (except [e AssertionError]
       (yield 4))))
  (assert (= (list (yield-from-test)) [0 1 2 1 2 3 4])))