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
15 use crate::{
16 description::Description,
17 matcher::{Matcher, MatcherResult},
18 };
19 use std::{fmt::Debug, marker::PhantomData};
20
21 /// Matches a value greater than or equal to (in the sense of `>=`) `expected`.
22 ///
23 /// The types of `ActualT` of `actual` and `ExpectedT` of `expected` must be
24 /// comparable via the `PartialOrd` trait. Namely, `ActualT` must implement
25 /// `PartialOrd<ExpectedT>`.
26 ///
27 /// ```
28 /// # use googletest::prelude::*;
29 /// # fn should_pass() -> Result<()> {
30 /// verify_that!(1, ge(0))?; // Passes
31 /// # Ok(())
32 /// # }
33 /// # fn should_fail() -> Result<()> {
34 /// verify_that!(0, ge(1))?; // Fails
35 /// # Ok(())
36 /// # }
37 /// # should_pass().unwrap();
38 /// # should_fail().unwrap_err();
39 /// ```
40 ///
41 /// In most cases the params neeed to be the same type or they need to be cast
42 /// explicitly. This can be surprising when comparing integer types or
43 /// references:
44 ///
45 /// ```compile_fail
46 /// # use googletest::prelude::*;
47 /// # fn should_not_compile() -> Result<()> {
48 /// verify_that!(123u32, ge(0u64))?; // Does not compile
49 /// verify_that!(123u32 as u64, ge(0u64))?; // Passes
50 /// # Ok(())
51 /// # }
52 /// ```
53 ///
54 /// ```compile_fail
55 /// # use googletest::prelude::*;
56 /// # fn should_not_compile() -> Result<()> {
57 /// let actual: &u32 = &2;
58 /// let expected: u32 = 0;
59 /// verify_that!(actual, ge(expected))?; // Does not compile
60 /// # Ok(())
61 /// # }
62 /// ```
63 ///
64 /// ```
65 /// # use googletest::prelude::*;
66 /// # fn should_pass() -> Result<()> {
67 /// let actual: &u32 = &2;
68 /// let expected: u32 = 0;
69 /// verify_that!(actual, ge(&expected))?; // Compiles and passes
70 /// # Ok(())
71 /// # }
72 /// # should_pass().unwrap();
73 /// ```
74 ///
75 /// You can find the standard library `PartialOrd` implementation in
76 /// <https://doc.rust-lang.org/core/cmp/trait.PartialOrd.html#implementors>
ge<ActualT: Debug + PartialOrd<ExpectedT>, ExpectedT: Debug>( expected: ExpectedT, ) -> impl Matcher<ActualT = ActualT>77 pub fn ge<ActualT: Debug + PartialOrd<ExpectedT>, ExpectedT: Debug>(
78 expected: ExpectedT,
79 ) -> impl Matcher<ActualT = ActualT> {
80 GeMatcher::<ActualT, _> { expected, phantom: Default::default() }
81 }
82
83 struct GeMatcher<ActualT, ExpectedT> {
84 expected: ExpectedT,
85 phantom: PhantomData<ActualT>,
86 }
87
88 impl<ActualT: Debug + PartialOrd<ExpectedT>, ExpectedT: Debug> Matcher
89 for GeMatcher<ActualT, ExpectedT>
90 {
91 type ActualT = ActualT;
92
matches(&self, actual: &ActualT) -> MatcherResult93 fn matches(&self, actual: &ActualT) -> MatcherResult {
94 (*actual >= self.expected).into()
95 }
96
describe(&self, matcher_result: MatcherResult) -> Description97 fn describe(&self, matcher_result: MatcherResult) -> Description {
98 match matcher_result {
99 MatcherResult::Match => {
100 format!("is greater than or equal to {:?}", self.expected).into()
101 }
102 MatcherResult::NoMatch => format!("is less than {:?}", self.expected).into(),
103 }
104 }
105 }
106
107 #[cfg(test)]
108 mod tests {
109 use super::ge;
110 use crate::matcher::{Matcher, MatcherResult};
111 use crate::prelude::*;
112 use indoc::indoc;
113 use std::ffi::OsString;
114
115 #[test]
ge_matches_i32_with_i32() -> Result<()>116 fn ge_matches_i32_with_i32() -> Result<()> {
117 let actual: i32 = 0;
118 let expected: i32 = 0;
119 verify_that!(actual, ge(expected))
120 }
121
122 #[test]
ge_does_not_match_smaller_i32() -> Result<()>123 fn ge_does_not_match_smaller_i32() -> Result<()> {
124 let matcher = ge(10);
125 let result = matcher.matches(&9);
126 verify_that!(result, eq(MatcherResult::NoMatch))
127 }
128
129 #[test]
ge_matches_bigger_str() -> Result<()>130 fn ge_matches_bigger_str() -> Result<()> {
131 verify_that!("B", ge("A"))
132 }
133
134 #[test]
ge_does_not_match_lesser_str() -> Result<()>135 fn ge_does_not_match_lesser_str() -> Result<()> {
136 let matcher = ge("z");
137 let result = matcher.matches(&"a");
138 verify_that!(result, eq(MatcherResult::NoMatch))
139 }
140
141 #[test]
ge_mismatch_contains_actual_and_expected() -> Result<()>142 fn ge_mismatch_contains_actual_and_expected() -> Result<()> {
143 let result = verify_that!(591, ge(927));
144
145 verify_that!(
146 result,
147 err(displays_as(contains_substring(indoc!(
148 "
149 Value of: 591
150 Expected: is greater than or equal to 927
151 Actual: 591,
152 which is less than 927
153 "
154 ))))
155 )
156 }
157
158 // Test `ge` matcher where actual is `&OsString` and expected is `&str`.
159 // Note that stdlib is a little bit inconsistent: `PartialOrd` exists for
160 // `OsString` and `str`, but only in one direction: it's only possible to
161 // compare `OsString` with `str` if `OsString` is on the left side of the
162 // ">=" operator (`impl PartialOrd<str> for OsString`).
163 //
164 // The comparison in the other direction is not defined.
165 //
166 // This means that the test case bellow effectively ensures that
167 // `verify_that(actual, ge(expected))` works if `actual >= expected` works
168 // (regardless whether the `expected >= actual` works`).
169 #[test]
ge_matches_owned_osstring_reference_with_string_reference() -> Result<()>170 fn ge_matches_owned_osstring_reference_with_string_reference() -> Result<()> {
171 let expected = "A";
172 let actual: OsString = "B".to_string().into();
173 verify_that!(&actual, ge(expected))
174 }
175
176 #[test]
ge_matches_ipv6addr_with_ipaddr() -> Result<()>177 fn ge_matches_ipv6addr_with_ipaddr() -> Result<()> {
178 use std::net::IpAddr;
179 use std::net::Ipv6Addr;
180 let actual: Ipv6Addr = "2001:4860:4860::8844".parse().unwrap();
181 let expected: IpAddr = "127.0.0.1".parse().unwrap();
182 verify_that!(actual, ge(expected))
183 }
184
185 #[test]
ge_matches_with_custom_partial_ord() -> Result<()>186 fn ge_matches_with_custom_partial_ord() -> Result<()> {
187 /// A custom "number" that is lower than all other numbers. The only
188 /// things we define about this "special" number is `PartialOrd` and
189 /// `PartialEq` against `u32`.
190 #[derive(Debug)]
191 struct VeryLowNumber {}
192
193 impl std::cmp::PartialEq<u32> for VeryLowNumber {
194 fn eq(&self, _other: &u32) -> bool {
195 false
196 }
197 }
198
199 // PartialOrd (required for >) requires PartialEq.
200 impl std::cmp::PartialOrd<u32> for VeryLowNumber {
201 fn partial_cmp(&self, _other: &u32) -> Option<std::cmp::Ordering> {
202 Some(std::cmp::Ordering::Less)
203 }
204 }
205
206 impl std::cmp::PartialEq<VeryLowNumber> for u32 {
207 fn eq(&self, _other: &VeryLowNumber) -> bool {
208 false
209 }
210 }
211
212 impl std::cmp::PartialOrd<VeryLowNumber> for u32 {
213 fn partial_cmp(&self, _other: &VeryLowNumber) -> Option<std::cmp::Ordering> {
214 Some(std::cmp::Ordering::Greater)
215 }
216 }
217
218 let actual: u32 = 42;
219 let expected = VeryLowNumber {};
220
221 verify_that!(actual, ge(expected))
222 }
223 }
224