bitpanda_csv/trade/
option.rs

1//! # Option
2//!
3//! This module defines the CsvOption type
4
5/// A CSV option
6#[derive(Debug, Deserialize, Copy, Clone, Eq, PartialEq, Hash)]
7#[serde(untagged)]
8pub enum CsvOption<T> {
9    Some(T),
10    None(NoneValue),
11}
12
13/// A dummy value to allow deserialization of `-`
14#[derive(Debug, Deserialize, Copy, Clone, Eq, PartialEq, Hash)]
15pub enum NoneValue {
16    #[serde(rename = "-")]
17    Null,
18}
19
20impl<T> CsvOption<T> {
21    pub fn unwrap(self) -> T {
22        match self {
23            Self::Some(v) => v,
24            Self::None(_) => panic!("unwrap on a None value"),
25        }
26    }
27
28    pub fn unwrap_or(self, alt: T) -> T {
29        match self {
30            Self::Some(v) => v,
31            Self::None(_) => alt,
32        }
33    }
34
35    /// Convert `CsvOption<T>` into a std `Option<T>`
36    pub fn option(self) -> Option<T> {
37        self.into()
38    }
39
40    pub fn none() -> Self {
41        Self::None(NoneValue::Null)
42    }
43}
44
45impl<T> From<CsvOption<T>> for Option<T> {
46    fn from(opt: CsvOption<T>) -> Self {
47        match opt {
48            CsvOption::Some(v) => Some(v),
49            CsvOption::None(_) => None,
50        }
51    }
52}
53
54#[cfg(test)]
55mod test {
56
57    use super::*;
58    use crate::Fiat;
59
60    use pretty_assertions::assert_eq;
61    use std::io::Cursor;
62
63    #[test]
64    fn should_unwrap_csv_option() {
65        assert_eq!(CsvOption::Some(Fiat::Eur).unwrap(), Fiat::Eur);
66    }
67
68    #[test]
69    #[should_panic]
70    fn should_panic_on_unwrap_csv_option() {
71        CsvOption::None(NoneValue::Null).unwrap()
72    }
73
74    #[test]
75    fn should_unwrap_csv_option_with_fallback() {
76        assert_eq!(CsvOption::Some(Fiat::Eur).unwrap_or(Fiat::Usd), Fiat::Eur);
77        assert_eq!(
78            CsvOption::None(NoneValue::Null).unwrap_or(Fiat::Usd),
79            Fiat::Usd
80        );
81    }
82
83    #[test]
84    fn should_convert_csv_option_to_option() {
85        let opt: Option<Fiat> = CsvOption::Some(Fiat::Eur).into();
86        assert_eq!(opt, Some(Fiat::Eur));
87        let opt: Option<Fiat> = CsvOption::None(NoneValue::Null).into();
88        assert_eq!(opt, None);
89    }
90
91    #[test]
92    fn should_decode_csv_option() {
93        let csv = r#"id,fiat
940,EUR
951,-
96"#;
97        let buffer = Cursor::new(csv);
98        let mut reader = csv::Reader::from_reader(buffer);
99        let mut fakes: Vec<CsvOption<Fiat>> = Vec::new();
100        for result in reader.deserialize::<Fake>() {
101            fakes.push(result.expect("failed to decode").fiat);
102        }
103        assert_eq!(
104            fakes,
105            vec![CsvOption::Some(Fiat::Eur), CsvOption::None(NoneValue::Null)]
106        );
107    }
108
109    #[derive(Deserialize)]
110    #[allow(dead_code)]
111    struct Fake {
112        id: u64,
113        fiat: CsvOption<Fiat>,
114    }
115}
bitpanda_csv/trade/option.rs

bitpanda_csv/trade/
option.rs
