/*
# Easy Average Grade Calculator 

This tool is a easy average grade average calulcator written in Rust. It takes a list of graded to calculated the average and can be used as a library by other applications.

See a more complex [grade calulcator](https://www.thebestdegree.com/grade-calculator/) for weighted grade calculation for college or high school students and teachers. 

These tools are all implemented in Rust.

## Usage ##

The easy grade calulcator can either read the input grades from arguments or a text file as shown below:

```bash
grade-avg 3.5 2.5
```

Another way to use the tool would be to create a txt file as the input grades. Create a input file `grades.txt` with the contents:

```
1.5
3.5
2.5
```

The average for these grades can be calculcated as below: 



```bash
cat ~/grades.txt | grade-avg
```
*/
use grades::Grade;

#[test]
fn test_parse_working() {
    if let Ok(grade) = Grade::from("1.3") {
        assert_eq!("1.3", format!("{}", grade));
    }
}

#[test]
fn test_parse_comma() {
    if let Ok(grade) = Grade::from("1,3") {
        assert_eq!("1.3", format!("{}", grade));
    } else {
        panic!("Failed to parse")
    }
}

#[test]
fn test_parse_out_of_bounds() {
    match Grade::from("6.0") {
        Ok(_) => assert!(false, "Should be out of bounds"),
        Err(_) => assert!(true),
    }
}
#[test]
fn test_avg_single() {
    let grade = new_grade("1.3");
    let grade_list = [grade];
    assert_eq!(Some(grade), grades::avg(&grade_list));
}

#[test]
fn test_avg_none() {
    assert_eq!(None, grades::avg(&[]));
}

#[test]
fn test_avg_two() {
    let expected = new_grade("1.5");
    assert_eq!(
        Some(expected),
        grades::avg(&[new_grade("1.0"), new_grade("2.0")])
    );
}

#[test]
fn test_print_correct_grade() {
    assert_eq!("Grade A", new_grade("1.0").verbal());
    assert_eq!("Grade A", new_grade("1.5").verbal());
    assert_ne!("Grade A", new_grade("1.6").verbal());
}

fn new_grade(input: &str) -> Grade {
    Grade::from(input).unwrap()
}