38 lines
944 B
Rust
38 lines
944 B
Rust
fn generate_nametag_text(name: String) -> Result<String, String> {
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// ^^^^^^ ^^^^^^
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if name.is_empty() {
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// `Err(String)` instead of `None`.
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Err("Empty names aren't allowed".to_string())
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} else {
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// `Ok` instead of `Some`.
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Ok(format!("Hi! My name is {name}"))
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}
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}
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fn main() {
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// You can optionally experiment here.
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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fn generates_nametag_text_for_a_nonempty_name() {
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assert_eq!(
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generate_nametag_text("Beyoncé".to_string()).as_deref(),
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Ok("Hi! My name is Beyoncé"),
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);
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}
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#[test]
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fn explains_why_generating_nametag_text_fails() {
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assert_eq!(
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generate_nametag_text(String::new())
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.as_ref()
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.map_err(|e| e.as_str()),
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Err("Empty names aren't allowed"),
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);
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}
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}
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