predicates/str/
basics.rs

1// Copyright (c) 2018 The predicates-rs Project Developers.
2//
3// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
4// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
5// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
6// option. This file may not be copied, modified, or distributed
7// except according to those terms.
8
9use std::fmt;
10
11use crate::reflection;
12use crate::utils;
13use crate::Predicate;
14
15/// Predicate that checks for empty strings.
16///
17/// This is created by `predicates::str::is_empty`.
18#[derive(Debug, Clone, Copy, PartialEq, Eq)]
19pub struct IsEmptyPredicate {}
20
21impl Predicate<str> for IsEmptyPredicate {
22    fn eval(&self, variable: &str) -> bool {
23        variable.is_empty()
24    }
25
26    fn find_case<'a>(&'a self, expected: bool, variable: &str) -> Option<reflection::Case<'a>> {
27        utils::default_find_case(self, expected, variable)
28            .map(|case| case.add_product(reflection::Product::new("var", variable.to_owned())))
29    }
30}
31
32impl reflection::PredicateReflection for IsEmptyPredicate {}
33
34impl fmt::Display for IsEmptyPredicate {
35    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
36        let palette = crate::Palette::new(f.alternate());
37        write!(
38            f,
39            "{}.{}()",
40            palette.var("var"),
41            palette.description("is_empty"),
42        )
43    }
44}
45
46/// Creates a new `Predicate` that ensures a str is empty
47///
48/// # Examples
49///
50/// ```
51/// use predicates::prelude::*;
52///
53/// let predicate_fn = predicate::str::is_empty();
54/// assert_eq!(true, predicate_fn.eval(""));
55/// assert_eq!(false, predicate_fn.eval("Food World"));
56/// ```
57pub fn is_empty() -> IsEmptyPredicate {
58    IsEmptyPredicate {}
59}
60
61/// Predicate checks start of str
62///
63/// This is created by `predicates::str::starts_with`.
64#[derive(Debug, Clone, PartialEq, Eq)]
65pub struct StartsWithPredicate {
66    pattern: String,
67}
68
69impl Predicate<str> for StartsWithPredicate {
70    fn eval(&self, variable: &str) -> bool {
71        variable.starts_with(&self.pattern)
72    }
73
74    fn find_case<'a>(&'a self, expected: bool, variable: &str) -> Option<reflection::Case<'a>> {
75        utils::default_find_case(self, expected, variable)
76            .map(|case| case.add_product(reflection::Product::new("var", variable.to_owned())))
77    }
78}
79
80impl reflection::PredicateReflection for StartsWithPredicate {}
81
82impl fmt::Display for StartsWithPredicate {
83    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
84        let palette = crate::Palette::new(f.alternate());
85        write!(
86            f,
87            "{}.{}({:?})",
88            palette.var("var"),
89            palette.description("starts_with"),
90            self.pattern
91        )
92    }
93}
94
95/// Creates a new `Predicate` that ensures a str starts with `pattern`
96///
97/// # Examples
98///
99/// ```
100/// use predicates::prelude::*;
101///
102/// let predicate_fn = predicate::str::starts_with("Hello");
103/// assert_eq!(true, predicate_fn.eval("Hello World"));
104/// assert_eq!(false, predicate_fn.eval("Goodbye World"));
105/// ```
106pub fn starts_with<P>(pattern: P) -> StartsWithPredicate
107where
108    P: Into<String>,
109{
110    StartsWithPredicate {
111        pattern: pattern.into(),
112    }
113}
114
115/// Predicate checks end of str
116///
117/// This is created by `predicates::str::ends_with`.
118#[derive(Debug, Clone, PartialEq, Eq)]
119pub struct EndsWithPredicate {
120    pattern: String,
121}
122
123impl Predicate<str> for EndsWithPredicate {
124    fn eval(&self, variable: &str) -> bool {
125        variable.ends_with(&self.pattern)
126    }
127
128    fn find_case<'a>(&'a self, expected: bool, variable: &str) -> Option<reflection::Case<'a>> {
129        utils::default_find_case(self, expected, variable)
130            .map(|case| case.add_product(reflection::Product::new("var", variable.to_owned())))
131    }
132}
133
134impl reflection::PredicateReflection for EndsWithPredicate {}
135
136impl fmt::Display for EndsWithPredicate {
137    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
138        let palette = crate::Palette::new(f.alternate());
139        write!(
140            f,
141            "{}.{}({:?})",
142            palette.var("var"),
143            palette.description("ends_with"),
144            self.pattern
145        )
146    }
147}
148
149/// Creates a new `Predicate` that ensures a str ends with `pattern`
150///
151/// # Examples
152///
153/// ```
154/// use predicates::prelude::*;
155///
156/// let predicate_fn = predicate::str::ends_with("World");
157/// assert_eq!(true, predicate_fn.eval("Hello World"));
158/// assert_eq!(false, predicate_fn.eval("Hello Moon"));
159/// ```
160pub fn ends_with<P>(pattern: P) -> EndsWithPredicate
161where
162    P: Into<String>,
163{
164    EndsWithPredicate {
165        pattern: pattern.into(),
166    }
167}
168
169/// Predicate that checks for patterns.
170///
171/// This is created by `predicates::str:contains`.
172#[derive(Debug, Clone, PartialEq, Eq)]
173pub struct ContainsPredicate {
174    pattern: String,
175}
176
177impl ContainsPredicate {
178    /// Require a specific count of matches.
179    ///
180    /// # Examples
181    ///
182    /// ```
183    /// use predicates::prelude::*;
184    ///
185    /// let predicate_fn = predicate::str::contains("Two").count(2);
186    /// assert_eq!(true, predicate_fn.eval("One Two Three Two One"));
187    /// assert_eq!(false, predicate_fn.eval("One Two Three"));
188    /// ```
189    pub fn count(self, count: usize) -> MatchesPredicate {
190        MatchesPredicate {
191            pattern: self.pattern,
192            count,
193        }
194    }
195}
196
197impl Predicate<str> for ContainsPredicate {
198    fn eval(&self, variable: &str) -> bool {
199        variable.contains(&self.pattern)
200    }
201
202    fn find_case<'a>(&'a self, expected: bool, variable: &str) -> Option<reflection::Case<'a>> {
203        utils::default_find_case(self, expected, variable)
204            .map(|case| case.add_product(reflection::Product::new("var", variable.to_owned())))
205    }
206}
207
208impl reflection::PredicateReflection for ContainsPredicate {}
209
210impl fmt::Display for ContainsPredicate {
211    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
212        let palette = crate::Palette::new(f.alternate());
213        write!(
214            f,
215            "{}.{}({})",
216            palette.var("var"),
217            palette.description("contains"),
218            palette.expected(&self.pattern),
219        )
220    }
221}
222
223/// Predicate that checks for repeated patterns.
224///
225/// This is created by `predicates::str::contains(...).count`.
226#[derive(Debug, Clone, PartialEq, Eq)]
227pub struct MatchesPredicate {
228    pattern: String,
229    count: usize,
230}
231
232impl Predicate<str> for MatchesPredicate {
233    fn eval(&self, variable: &str) -> bool {
234        variable.matches(&self.pattern).count() == self.count
235    }
236
237    fn find_case<'a>(&'a self, expected: bool, variable: &str) -> Option<reflection::Case<'a>> {
238        let actual_count = variable.matches(&self.pattern).count();
239        let result = self.count == actual_count;
240        if result == expected {
241            Some(
242                reflection::Case::new(Some(self), result)
243                    .add_product(reflection::Product::new("var", variable.to_owned()))
244                    .add_product(reflection::Product::new("actual count", actual_count)),
245            )
246        } else {
247            None
248        }
249    }
250}
251
252impl reflection::PredicateReflection for MatchesPredicate {
253    fn parameters<'a>(&'a self) -> Box<dyn Iterator<Item = reflection::Parameter<'a>> + 'a> {
254        let params = vec![reflection::Parameter::new("count", &self.count)];
255        Box::new(params.into_iter())
256    }
257}
258
259impl fmt::Display for MatchesPredicate {
260    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
261        let palette = crate::Palette::new(f.alternate());
262        write!(
263            f,
264            "{}.{}({})",
265            palette.var("var"),
266            palette.description("contains"),
267            palette.expected(&self.pattern),
268        )
269    }
270}
271
272/// Creates a new `Predicate` that ensures a str contains `pattern`
273///
274/// # Examples
275///
276/// ```
277/// use predicates::prelude::*;
278///
279/// let predicate_fn = predicate::str::contains("Two");
280/// assert_eq!(true, predicate_fn.eval("One Two Three"));
281/// assert_eq!(false, predicate_fn.eval("Four Five Six"));
282/// ```
283pub fn contains<P>(pattern: P) -> ContainsPredicate
284where
285    P: Into<String>,
286{
287    ContainsPredicate {
288        pattern: pattern.into(),
289    }
290}
predicates/str/basics.rs

predicates/str/
basics.rs
