musli 0.1.5

Müsli is a flexible and efficient serialization framework.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147

use anyhow::Result;
use musli::alloc::Global;
use musli::json;
use musli::value::{self, Value};
use musli::{Decode, Encode};

#[derive(Decode, Encode)]
struct Struct {
    #[musli(default, skip_encoding_if = Option::is_none)]
    field: Option<u32>,
}

/// We want to assert that an option type can be decode from a plain unknown value.
#[test]
fn option() -> Result<()> {
    let value: Value<Global> = json::from_str(r#"{"field":null}"#)?;
    let st: Struct = value::decode_text(&value)?;
    assert_eq!(st.field, None);

    let value: Value<Global> = json::from_str(r#"{"field":42}"#)?;
    let st: Struct = value::decode_text(&value)?;
    assert_eq!(st.field, Some(42));

    let value: Value<Global> = json::from_str(r#"{}"#)?;
    let st: Struct = value::decode_text(&value)?;
    assert_eq!(st.field, None);
    Ok(())
}

/// Numbers are implicitly converted when decoded out of a value.
#[test]
fn number_coercion() -> Result<()> {
    let value = Value::<Global>::from(42u8);
    assert_eq!(value::decode::<u64>(&value)?, 42u64);
    assert_eq!(value::decode::<i32>(&value)?, 42i32);
    assert_eq!(value::decode::<f32>(&value)?, 42.0f32);

    let value = Value::<Global>::from(-1i64);
    assert_eq!(value::decode::<i8>(&value)?, -1i8);
    assert_eq!(value::decode::<f64>(&value)?, -1.0f64);
    assert!(value::decode::<u32>(&value).is_err());

    let value = Value::<Global>::from(3.5f32);
    assert_eq!(value::decode::<f64>(&value)?, 3.5f64);
    assert_eq!(value::decode::<u32>(&value)?, 3u32);

    let value = Value::<Global>::from(u128::MAX);
    assert_eq!(value::decode::<u128>(&value)?, u128::MAX);
    assert!(value::decode::<i128>(&value).is_err());

    let value = Value::<Global>::from(i128::MIN);
    assert_eq!(value::decode::<i128>(&value)?, i128::MIN);
    Ok(())
}

/// Floats which do not fit in the target integer type are rejected rather than
/// silently saturating.
#[test]
fn float_to_integer_coercion() -> Result<()> {
    // Truncation towards zero is fine as long as the result is in range.
    assert_eq!(value::decode::<i32>(&Value::<Global>::from(-3.5f64))?, -3);
    assert_eq!(value::decode::<u8>(&Value::<Global>::from(255.9f64))?, 255);
    assert_eq!(
        value::decode::<u64>(&Value::<Global>::from(9.007199254740992e15f64))?,
        9007199254740992
    );

    // Out of range in either direction.
    assert!(value::decode::<u8>(&Value::<Global>::from(1e30f64)).is_err());
    assert!(value::decode::<u64>(&Value::<Global>::from(1e30f64)).is_err());
    assert!(value::decode::<u32>(&Value::<Global>::from(-1.0f64)).is_err());
    assert!(value::decode::<i8>(&Value::<Global>::from(128.0f64)).is_err());
    assert!(value::decode::<u64>(&Value::<Global>::from(1.8446744073709552e19f64)).is_err());

    // Non-finite values are never integers.
    assert!(value::decode::<u8>(&Value::<Global>::from(f64::NAN)).is_err());
    assert!(value::decode::<i32>(&Value::<Global>::from(f64::INFINITY)).is_err());
    assert!(value::decode::<i32>(&Value::<Global>::from(f64::NEG_INFINITY)).is_err());
    Ok(())
}

/// A JSON document with numerical map keys must decode the same whether or not
/// it is routed through a [`Value`], since object keys are always strings.
#[test]
fn numeric_map_keys() -> Result<()> {
    use std::collections::BTreeMap;

    for (input, expected) in [
        (r#"{}"#, BTreeMap::new()),
        (r#"{"1":2}"#, BTreeMap::from([(1u32, 2u32)])),
        (
            r#"{"0":1,"4294967295":2}"#,
            BTreeMap::from([(0u32, 1u32), (u32::MAX, 2u32)]),
        ),
    ] {
        assert_eq!(json::from_str::<BTreeMap<u32, u32>>(input)?, expected);

        let value: Value<Global> = json::from_str(input)?;
        assert_eq!(value::decode_text::<BTreeMap<u32, u32>>(&value)?, expected);
    }

    // Signed and wide keys.
    let expected = BTreeMap::from([(i64::MIN, 1u32), (-1i64, 2u32)]);
    let value: Value<Global> = json::from_str(&json::to_string(&expected)?)?;
    assert_eq!(value::decode_text::<BTreeMap<i64, u32>>(&value)?, expected);

    let expected = BTreeMap::from([(u128::MAX, 1u32)]);
    let value: Value<Global> = json::from_str(&json::to_string(&expected)?)?;
    assert_eq!(value::decode_text::<BTreeMap<u128, u32>>(&value)?, expected);

    // Binary mode does not coerce string keys into numbers.
    let value: Value<Global> = json::from_str(r#"{"1":2}"#)?;
    assert!(value::decode::<BTreeMap<u32, u32>>(&value).is_err());
    Ok(())
}

/// The exact number representation is preserved.
#[test]
fn number_representation() -> Result<()> {
    let value: Value<Global> = value::encode(-3i16)?;
    assert!(value.is_i16());
    assert_eq!(format!("{value:?}"), "-3");

    let value: Value<Global> = value::encode(1.5f32)?;
    assert!(value.is_f32());
    assert_eq!(format!("{value:?}"), "1.5");
    Ok(())
}

/// A `usize` and an `isize` use the platform specific representation.
#[test]
fn platform_sized_integers() -> Result<()> {
    let value: Value<Global> = value::encode(42usize)?;
    assert!(value.is_usize());
    #[cfg(target_pointer_width = "32")]
    assert_eq!(value, Value::from(42u32));
    #[cfg(target_pointer_width = "64")]
    assert_eq!(value, Value::from(42u64));

    let value: Value<Global> = value::encode(-42isize)?;
    assert!(value.is_isize());
    #[cfg(target_pointer_width = "32")]
    assert_eq!(value, Value::from(-42i32));
    #[cfg(target_pointer_width = "64")]
    assert_eq!(value, Value::from(-42i64));
    Ok(())
}