googletest/matchers/
some_matcher.rs

1// Copyright 2022 Google LLC
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//      http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15use crate::{
16    description::Description,
17    matcher::{Matcher, MatcherBase, MatcherResult},
18};
19use std::fmt::Debug;
20
21/// Matches an `Option` containing a value matched by `inner`.
22///
23/// ```
24/// # use googletest::prelude::*;
25/// # fn should_pass() -> Result<()> {
26/// verify_that!(Some("Some value"), some(eq("Some value")))?;  // Passes
27/// #     Ok(())
28/// # }
29/// # fn should_fail_1() -> Result<()> {
30/// verify_that!(None::<&str>, some(eq("Some value")))?;   // Fails
31/// #     Ok(())
32/// # }
33/// # fn should_fail_2() -> Result<()> {
34/// verify_that!(Some("Some value"), some(eq("Some other value")))?;   // Fails
35/// #     Ok(())
36/// # }
37/// # should_pass().unwrap();
38/// # should_fail_1().unwrap_err();
39/// # should_fail_2().unwrap_err();
40/// ```
41pub fn some<Inner>(inner: Inner) -> SomeMatcher<Inner> {
42    SomeMatcher { inner }
43}
44
45#[derive(MatcherBase)]
46pub struct SomeMatcher<InnerMatcherT> {
47    inner: InnerMatcherT,
48}
49
50impl<T: Debug + Copy, InnerMatcherT: Matcher<T>> Matcher<Option<T>> for SomeMatcher<InnerMatcherT> {
51    fn matches(&self, actual: Option<T>) -> MatcherResult {
52        actual.map(|v| self.inner.matches(v)).unwrap_or(MatcherResult::NoMatch)
53    }
54
55    fn explain_match(&self, actual: Option<T>) -> Description {
56        match (self.matches(actual), actual) {
57            (_, Some(t)) => {
58                Description::new().text("which has a value").nested(self.inner.explain_match(t))
59            }
60            (_, None) => "which is None".into(),
61        }
62    }
63
64    fn describe(&self, matcher_result: MatcherResult) -> Description {
65        match matcher_result {
66            MatcherResult::Match => {
67                format!("has a value which {}", self.inner.describe(MatcherResult::Match)).into()
68            }
69            MatcherResult::NoMatch => format!(
70                "is None or has a value which {}",
71                self.inner.describe(MatcherResult::NoMatch)
72            )
73            .into(),
74        }
75    }
76}
77
78impl<'a, T: Debug, InnerMatcherT: Matcher<&'a T>> Matcher<&'a Option<T>>
79    for SomeMatcher<InnerMatcherT>
80{
81    fn matches(&self, actual: &'a Option<T>) -> MatcherResult {
82        actual.as_ref().map(|v| self.inner.matches(v)).unwrap_or(MatcherResult::NoMatch)
83    }
84
85    fn explain_match(&self, actual: &'a Option<T>) -> Description {
86        match (self.matches(actual), actual) {
87            (_, Some(t)) => {
88                Description::new().text("which has a value").nested(self.inner.explain_match(t))
89            }
90            (_, None) => "which is None".into(),
91        }
92    }
93
94    fn describe(&self, matcher_result: MatcherResult) -> Description {
95        match matcher_result {
96            MatcherResult::Match => {
97                format!("has a value which {}", self.inner.describe(MatcherResult::Match)).into()
98            }
99            MatcherResult::NoMatch => format!(
100                "is None or has a value which {}",
101                self.inner.describe(MatcherResult::NoMatch)
102            )
103            .into(),
104        }
105    }
106}
107
108#[cfg(test)]
109mod tests {
110    use crate::matcher::MatcherResult;
111    use crate::prelude::*;
112    use crate::Result;
113    use indoc::indoc;
114
115    #[test]
116    fn some_matches_option_with_value() -> Result<()> {
117        let matcher = some(eq(1));
118
119        let result = matcher.matches(Some(1));
120
121        verify_that!(result, eq(MatcherResult::Match))
122    }
123
124    #[test]
125    fn some_does_not_match_option_with_wrong_value() -> Result<()> {
126        let matcher = some(eq(1));
127
128        let result = matcher.matches(Some(0));
129
130        verify_that!(result, eq(MatcherResult::NoMatch))
131    }
132
133    #[test]
134    fn some_does_not_match_option_with_none() -> Result<()> {
135        let matcher = some(eq(1));
136
137        let result = matcher.matches(None::<i32>);
138
139        verify_that!(result, eq(MatcherResult::NoMatch))
140    }
141
142    #[test]
143    fn some_matches_option_with_by_ref_value() -> Result<()> {
144        verify_that!(Some("123".to_string()), some(eq("123")))
145    }
146
147    #[test]
148    fn some_does_not_match_option_with_wrong_by_ref_value() -> Result<()> {
149        verify_that!(Some("321".to_string()), not(some(eq("123"))))
150    }
151
152    #[test]
153    fn some_does_not_match_option_with_by_ref_none() -> Result<()> {
154        verify_that!(None::<String>, not(some(eq("123"))))
155    }
156
157    #[test]
158    fn some_full_error_message() -> Result<()> {
159        let result = verify_that!(Some(2), some(eq(1)));
160        verify_that!(
161            result,
162            err(displays_as(contains_substring(indoc!(
163                "
164                    Value of: Some(2)
165                    Expected: has a value which is equal to 1
166                    Actual: Some(2),
167                      which has a value
168                        which isn't equal to 1
169                "
170            ))))
171        )
172    }
173
174    #[test]
175    fn some_describe_matches() -> Result<()> {
176        verify_that!(
177            Matcher::<Option<i32>>::describe(&some(eq(1)), MatcherResult::Match),
178            displays_as(eq("has a value which is equal to 1"))
179        )
180    }
181
182    #[test]
183    fn some_describe_does_not_match() -> Result<()> {
184        verify_that!(
185            Matcher::<Option<i32>>::describe(&some(eq(1)), MatcherResult::NoMatch),
186            displays_as(eq("is None or has a value which isn't equal to 1"))
187        )
188    }
189
190    #[test]
191    fn some_describe_matches_of_by_ref() -> Result<()> {
192        verify_that!(
193            Matcher::<Option<&String>>::describe(&some(eq("123")), MatcherResult::Match),
194            displays_as(eq("has a value which is equal to \"123\""))
195        )
196    }
197
198    #[test]
199    fn some_describe_does_not_match_of_by_ref() -> Result<()> {
200        verify_that!(
201            Matcher::<Option<&String>>::describe(&some(eq("123")), MatcherResult::NoMatch),
202            displays_as(eq("is None or has a value which isn't equal to \"123\""))
203        )
204    }
205
206    #[test]
207    fn some_explain_match_with_none() -> Result<()> {
208        verify_that!(some(eq(1)).explain_match(None::<i32>), displays_as(eq("which is None")))
209    }
210
211    #[test]
212    fn some_explain_match_with_some_success() -> Result<()> {
213        verify_that!(
214            some(eq(1)).explain_match(Some(1)),
215            displays_as(eq("which has a value\n  which is equal to 1"))
216        )
217    }
218
219    #[test]
220    fn some_explain_match_with_some_fail() -> Result<()> {
221        verify_that!(
222            some(eq(1)).explain_match(Some(2)),
223            displays_as(eq("which has a value\n  which isn't equal to 1"))
224        )
225    }
226
227    #[test]
228    fn some_explain_match_with_none_by_ref() -> Result<()> {
229        verify_that!(
230            some(eq("123")).explain_match(&None::<String>),
231            displays_as(eq("which is None"))
232        )
233    }
234
235    #[test]
236    fn some_explain_match_with_some_success_by_ref() -> Result<()> {
237        verify_that!(
238            some(eq("123")).explain_match(&Some("123".to_string())),
239            displays_as(eq("which has a value\n  which is equal to \"123\""))
240        )
241    }
242
243    #[test]
244    fn some_explain_match_with_some_fail_by_ref() -> Result<()> {
245        verify_that!(
246            some(eq("123")).explain_match(&Some("321".to_string())),
247            displays_as(eq("which has a value\n  which isn't equal to \"123\""))
248        )
249    }
250}
googletest/matchers/some_matcher.rs

googletest/matchers/
some_matcher.rs
