fluent_assertions/assertions/
string_assertion.rs

1use crate::Assertion;
2
3/// Specific assertions for strings
4impl<T: AsRef<str>> Assertion<T> {
5    /// Asserts that the string is empty
6    pub fn be_empty(&self) -> &Self {
7        assert!(
8            self.value.as_ref().is_empty(),
9            "Expected string to be empty, but got '{}'",
10            self.value.as_ref()
11        );
12        self
13    }
14    /// Asserts that the string is not empty
15    pub fn not_be_empty(&self) -> &Self {
16        assert!(
17            !self.value.as_ref().is_empty(),
18            "Expected string to not be empty, but got empty string"
19        );
20        self
21    }
22    /// Asserts that the string starts with a given prefix
23    pub fn start_with(&self, prefix: &str) -> &Self {
24        assert!(
25            self.value.as_ref().starts_with(prefix),
26            "Expected string to start with '{}', but it started with '{}'",
27            prefix,
28            &self.value.as_ref()[0..prefix.len()]
29        );
30        self
31    }
32    /// Asserts that the string ends with a given suffix
33    pub fn end_with(&self, suffix: &str) -> &Self {
34        assert!(
35            self.value.as_ref().ends_with(suffix),
36            "Expected string to end with '{}', but it ended with '{}'",
37            suffix,
38            &self.value.as_ref()[self.value.as_ref().len() - suffix.len()..]
39        );
40        self
41    }
42
43    /// Asserts that the string contains a given substring
44    pub fn contain(&self, substring: &str) -> &Self {
45        assert!(
46            self.value.as_ref().contains(substring),
47            "Expected string to contain '{}', but it didn't",
48            substring
49        );
50        self
51    }
52
53    /// Asserts that the string has a given length
54    pub fn have_length(&self, length: usize) -> &Self {
55        assert!(
56            self.value.as_ref().len() == length,
57            "Expected string to have length {}, but it had length {}",
58            length,
59            self.value.as_ref().len()
60        );
61        self
62    }
63}
64
65#[cfg(test)]
66mod tests {
67    use crate::assertions::*;
68    use rstest::*;
69
70    #[test]
71    fn test_str_assertions() {
72        let actual = "ABCDEFGHI";
73        actual
74            .should()
75            .start_with("AB")
76            .end_with("HI")
77            .contain("EF")
78            .have_length(9);
79    }
80
81    #[test]
82    fn test_string_assertions() {
83        let actual_string = "ABCDEFGHI".to_string();
84        actual_string
85            .should()
86            .start_with("AB")
87            .end_with("HI")
88            .contain("EF")
89            .have_length(9);
90    }
91
92    #[rstest]
93    #[case(String::default())]
94    #[case(String::from(""))]
95    #[case("".to_string())]
96    fn should_be_empty(#[case] input: String) {
97        input.should().be_empty();
98    }
99
100    #[rstest]
101    #[case(String::from("hello"))]
102    #[case("42".to_string())]
103    fn should_not_be_empty(#[case] input: String) {
104        input.should().not_be_empty();
105    }
106
107    #[rstest]
108    #[case("hello")]
109    #[case("42")]
110    fn should_be(#[case] input: &str) {
111        input.should().be(input);
112    }
113}
fluent_assertions/assertions/string_assertion.rs

fluent_assertions/assertions/
string_assertion.rs
