| 1 | 1 | | //! Greetings. |
| 2 | 2 | | |
| 3 | | - | /// The greeting for `name`. |
| 4 | | - | pub fn greeting(name: &str) -> String { |
| 5 | | - | let trimmed = name.trim(); |
| 6 | | - | let display_name = if trimmed.is_empty() { "world" } else { trimmed }; |
| 7 | | - | format!("Hello, {display_name}!") |
| 3 | + | /// Languages that can be greeted in, as accepted by `--lang`. |
| 4 | + | pub const LANGUAGES: [&str; 3] = ["en", "es", "fr"]; |
| 5 | + | |
| 6 | + | /// The greeting for `name` in the language `lang`. |
| 7 | + | /// |
| 8 | + | /// Returns an error naming the supported languages if `lang` is unknown. |
| 9 | + | pub fn greeting(name: &str, lang: &str) -> Result<String, String> { |
| 10 | + | match lang { |
| 11 | + | "en" => Ok(format!("Hello, {name}!")), |
| 12 | + | "es" => Ok(format!("¡Hola, {name}!")), |
| 13 | + | "fr" => Ok(format!("Bonjour, {name} !")), |
| 14 | + | _ => Err(format!( |
| 15 | + | "unsupported language '{lang}' (supported: {})", |
| 16 | + | LANGUAGES.join(", ") |
| 17 | + | )), |
| 18 | + | } |
| 8 | 19 | | } |
| 9 | 20 | | |
| 10 | 21 | | #[cfg(test)] |
| ⋯ |
| 13 | 24 | | |
| 14 | 25 | | #[test] |
| 15 | 26 | | fn greets_by_name() { |
| 16 | | - | assert_eq!(greeting("Ada"), "Hello, Ada!"); |
| 27 | + | assert_eq!(greeting("Ada", "en").unwrap(), "Hello, Ada!"); |
| 17 | 28 | | } |
| 18 | 29 | | |
| 19 | 30 | | #[test] |
| 20 | | - | fn greets_world_with_empty_string() { |
| 21 | | - | assert_eq!(greeting(""), "Hello, world!"); |
| 31 | + | fn greets_in_spanish() { |
| 32 | + | assert_eq!(greeting("Ana", "es").unwrap(), "¡Hola, Ana!"); |
| 22 | 33 | | } |
| 23 | 34 | | |
| 24 | 35 | | #[test] |
| 25 | | - | fn greets_world_with_whitespace_only() { |
| 26 | | - | assert_eq!(greeting(" "), "Hello, world!"); |
| 36 | + | fn greets_in_french() { |
| 37 | + | assert_eq!(greeting("Luc", "fr").unwrap(), "Bonjour, Luc !"); |
| 27 | 38 | | } |
| 28 | 39 | | |
| 29 | 40 | | #[test] |
| 30 | | - | fn trims_whitespace_from_name() { |
| 31 | | - | assert_eq!(greeting(" Ada "), "Hello, Ada!"); |
| 41 | + | fn rejects_unknown_language() { |
| 42 | + | let err = greeting("Ada", "de").unwrap_err(); |
| 43 | + | assert!(err.contains("en, es, fr")); |
| 32 | 44 | | } |
| 33 | 45 | | } |