rustlings/exercises/generics/generics3.rs

// An imaginary magical school has a new report card generation system written in Rust!
// Currently the system only supports creating report cards where the student's grade
// is represented numerically (e.g. 1.0 -> 5.5).
// However, the school also issues alphabetical grades (A+ -> F-) and needs
// to be able to print both types of report card!

// Make the necessary code changes in the struct ReportCard and the impl block
// to support alphabetical report cards. Change the Grade in the second test to "A+"
// to show that your changes allow alphabetical grades.

// Execute 'rustlings hint generics3' for hints!

fn main() {}

pub struct ReportCard {
    pub grade: f32,
    pub student_name: String,
    pub student_age: u8,
    pub alpha: bool,
}

impl ReportCard {
    pub fn get_alpha(&self) -> String {
        if self.grade > 4.0 {
            format!("A+")
        } else {
            format!("B")
        }
    }
    pub fn print(&self) -> String {
        let grade = if self.alpha {
            self.get_alpha()
        } else {
            self.grade.to_string()
        };
        format!(
            "{} ({}) - achieved a grade of {}",
            &self.student_name, &self.student_age, grade
        )
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn generate_numeric_report_card() {
        let report_card = ReportCard {
            grade: 2.1,
            student_name: "Tom Wriggle".to_string(),
            student_age: 12,
            alpha: false,
        };
        assert_eq!(
            report_card.print(),
            "Tom Wriggle (12) - achieved a grade of 2.1"
        );
    }

    #[test]
    fn generate_alphabetic_report_card() {
        // TODO: Make sure to change the grade here after you finish the exercise.
        let report_card = ReportCard {
            grade: 4.1,
            student_name: "Gary Plotter".to_string(),
            student_age: 11,
            alpha: true,
        };
        assert_eq!(
            report_card.print(),
            "Gary Plotter (11) - achieved a grade of A+"
        );
    }
}