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Diffstat (limited to 'rustlings/exercises/13_error_handling/errors1.rs')
| -rw-r--r-- | rustlings/exercises/13_error_handling/errors1.rs | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/rustlings/exercises/13_error_handling/errors1.rs b/rustlings/exercises/13_error_handling/errors1.rs new file mode 100644 index 0000000..e07fddc --- /dev/null +++ b/rustlings/exercises/13_error_handling/errors1.rs @@ -0,0 +1,41 @@ +// TODO: This function refuses to generate text to be printed on a nametag if +// you pass it an empty string. It'd be nicer if it explained what the problem +// was instead of just returning `None`. Thankfully, Rust has a similar +// construct to `Option` that can be used to express error conditions. Change +// the function signature and body to return `Result<String, String>` instead +// of `Option<String>`. +fn generate_nametag_text(name: String) -> Option<String> { + if name.is_empty() { + // Empty names aren't allowed + None + } else { + Some(format!("Hi! My name is {name}")) + } +} + +fn main() { + // You can optionally experiment here. +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn generates_nametag_text_for_a_nonempty_name() { + assert_eq!( + generate_nametag_text("Beyoncé".to_string()).as_deref(), + Ok("Hi! My name is Beyoncé"), + ); + } + + #[test] + fn explains_why_generating_nametag_text_fails() { + assert_eq!( + generate_nametag_text(String::new()) + .as_ref() + .map_err(|e| e.as_str()), + Err("Empty names aren't allowed"), + ); + } +} |