vendor/unic-char-range/tests/iter_tests.rs

   1 // Copyright 2017 The UNIC Project Developers.
   2 //
   3 // See the COPYRIGHT file at the top-level directory of this distribution.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 use std::{char, u32, vec};
  12
  13 use unic_char_range::CharRange;
  14
  15 fn all_chars() -> vec::IntoIter<char> {
  16     (u32::MIN..u32::MAX)
  17         .take_while(|&u| u <= char::MAX as u32)
  18         .filter_map(char::from_u32)
  19         .collect::<Vec<_>>()
  20         .into_iter()
  21 }
  22
  23 #[test]
  24 fn test_iter_all_chars() {
  25     assert!(CharRange::all().iter().eq(all_chars()))
  26 }
  27
  28 #[test]
  29 fn test_iter_all_chars_rev() {
  30     assert!(CharRange::all().iter().rev().eq(all_chars().rev()))
  31 }
  32
  33 #[test]
  34 fn test_iter_all_chars_mixed_next_back() {
  35     let mut custom = CharRange::all().iter();
  36     let mut simple = all_chars();
  37     while let Some(custom_char) = custom.next() {
  38         assert_eq!(Some(custom_char), simple.next());
  39         assert_eq!(custom.next_back(), simple.next_back());
  40     }
  41     assert_eq!(None, simple.next());
  42 }
  43
  44 #[test]
  45 fn test_iter_all_chars_into_iter() {
  46     for _ch in CharRange::all() {
  47         // nothing
  48     }
  49 }
  50
  51 #[test]
  52 fn test_iter_fused() {
  53     let mut iter = CharRange::all().iter();
  54     let mut fused = all_chars().fuse();
  55     assert!(iter.by_ref().eq(fused.by_ref()));
  56     for _ in 0..100 {
  57         assert_eq!(iter.next(), fused.next());
  58     }
  59 }
  60
  61 #[test]
  62 fn test_iter_exact_trusted_len() {
  63     fn assert_presents_right_len<I: ExactSizeIterator>(iter: &I, len: usize) {
  64         assert_eq!(iter.len(), len);
  65         assert_eq!(iter.size_hint(), (len, Some(len)));
  66     }
  67
  68     let mut iter = CharRange::all().iter();
  69     let mut predicted_length = iter.len();
  70     assert_eq!(predicted_length, all_chars().len());
  71
  72     while let Some(_) = iter.next() {
  73         predicted_length -= 1;
  74         assert_presents_right_len(&iter, predicted_length);
  75     }
  76
  77     assert_presents_right_len(&iter, 0);
  78 }