1 use crate::{lowercase, transform}; 2 3 /// This trait defines a snake case conversion. 4 /// 5 /// In snake_case, word boundaries are indicated by underscores. 6 /// 7 /// ## Example: 8 /// 9 /// ```rust 10 /// use heck::SnakeCase; 11 /// 12 /// let sentence = "We carry a new world here, in our hearts."; 13 /// assert_eq!(sentence.to_snake_case(), "we_carry_a_new_world_here_in_our_hearts"); 14 /// ``` 15 pub trait SnakeCase: ToOwned { 16 /// Convert this type to snake case. to_snake_case(&self) -> Self::Owned17 fn to_snake_case(&self) -> Self::Owned; 18 } 19 20 /// Oh heck, SnekCase is an alias for SnakeCase. See SnakeCase for 21 /// more documentation. 22 pub trait SnekCase: ToOwned { 23 /// Convert this type to snek case. to_snek_case(&self) -> Self::Owned24 fn to_snek_case(&self) -> Self::Owned; 25 } 26 27 impl<T: ?Sized + SnakeCase> SnekCase for T { to_snek_case(&self) -> Self::Owned28 fn to_snek_case(&self) -> Self::Owned { 29 self.to_snake_case() 30 } 31 } 32 33 impl SnakeCase for str { to_snake_case(&self) -> String34 fn to_snake_case(&self) -> String { 35 transform(self, lowercase, |s| s.push('_')) 36 } 37 } 38 39 #[cfg(test)] 40 mod tests { 41 use super::SnakeCase; 42 43 macro_rules! t { 44 ($t:ident : $s1:expr => $s2:expr) => { 45 #[test] 46 fn $t() { 47 assert_eq!($s1.to_snake_case(), $s2) 48 } 49 }; 50 } 51 52 t!(test1: "CamelCase" => "camel_case"); 53 t!(test2: "This is Human case." => "this_is_human_case"); 54 t!(test3: "MixedUP CamelCase, with some Spaces" => "mixed_up_camel_case_with_some_spaces"); 55 t!(test4: "mixed_up_ snake_case with some _spaces" => "mixed_up_snake_case_with_some_spaces"); 56 t!(test5: "kebab-case" => "kebab_case"); 57 t!(test6: "SHOUTY_SNAKE_CASE" => "shouty_snake_case"); 58 t!(test7: "snake_case" => "snake_case"); 59 t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "this_contains_all_kinds_of_word_boundaries"); 60 t!(test9: "XΣXΣ baffle" => "xσxς_baffle"); 61 t!(test10: "XMLHttpRequest" => "xml_http_request"); 62 t!(test11: "FIELD_NAME11" => "field_name11"); 63 t!(test12: "99BOTTLES" => "99bottles"); 64 t!(test13: "FieldNamE11" => "field_nam_e11"); 65 66 t!(test14: "abc123def456" => "abc123def456"); 67 t!(test16: "abc123DEF456" => "abc123_def456"); 68 t!(test17: "abc123Def456" => "abc123_def456"); 69 t!(test18: "abc123DEf456" => "abc123_d_ef456"); 70 t!(test19: "ABC123def456" => "abc123def456"); 71 t!(test20: "ABC123DEF456" => "abc123def456"); 72 t!(test21: "ABC123Def456" => "abc123_def456"); 73 t!(test22: "ABC123DEf456" => "abc123d_ef456"); 74 t!(test23: "ABC123dEEf456FOO" => "abc123d_e_ef456_foo"); 75 t!(test24: "abcDEF" => "abc_def"); 76 t!(test25: "ABcDE" => "a_bc_de"); 77 } 78