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
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192

//! Error types for runtimes.
pub use oasis_core_runtime::types::Error as RuntimeError;

use crate::{dispatcher, module::CallResult};

/// A runtime error that gets propagated to the caller.
///
/// It extends `std::error::Error` with module name and error code so that errors can be easily
/// serialized and transferred between different processes.
///
/// This trait can be derived:
/// ```
/// # #[cfg(feature = "oasis-runtime-sdk-macros")]
/// # mod example {
/// # use oasis_runtime_sdk_macros::Error;
/// const MODULE_NAME: &str = "my-module";
/// #[derive(Clone, Debug, Error, thiserror::Error)]
/// #[sdk_error(autonumber)] // `module_name` meta is required if `MODULE_NAME` isn't in scope
/// enum Error {
///    #[error("invalid argument")]
///    InvalidArgument,          // autonumbered to 0
///
///    #[error("forbidden")]
///    #[sdk_error(code = 401)]  // manually numbered to 403 (`code` or autonumbering is required)
///    Forbidden,
/// }
/// # }
/// ```
pub trait Error: std::error::Error {
    /// Name of the module that emitted the error.
    fn module_name(&self) -> &str;

    /// Error code uniquely identifying the error.
    fn code(&self) -> u32;

    /// Converts the error into a call result.
    fn into_call_result(self) -> CallResult
    where
        Self: Sized,
    {
        match self.into_abort() {
            Ok(err) => CallResult::Aborted(err),
            Err(failed) => CallResult::Failed {
                module: failed.module_name().to_owned(),
                code: failed.code(),
                message: failed.to_string(),
            },
        }
    }

    /// Consumes self and returns either `Ok(err)` (where `err` is a dispatcher error) when batch
    /// should abort or `Err(self)` when this is just a regular error.
    fn into_abort(self) -> Result<dispatcher::Error, Self>
    where
        Self: Sized,
    {
        Err(self)
    }
}

impl Error for std::convert::Infallible {
    fn module_name(&self) -> &str {
        "(none)"
    }

    fn code(&self) -> u32 {
        Default::default()
    }
}

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

    const MODULE_NAME_1: &str = "test1";
    const MODULE_NAME_2: &str = "test2";

    #[derive(thiserror::Error, Debug, oasis_runtime_sdk_macros::Error)]
    #[sdk_error(module_name = "MODULE_NAME_1")]
    enum ChildError {
        #[error("first error")]
        #[sdk_error(code = 1)]
        Error1,

        #[error("second error")]
        #[sdk_error(code = 2)]
        Error2,
    }

    #[derive(thiserror::Error, Debug, oasis_runtime_sdk_macros::Error)]
    #[sdk_error(module_name = "MODULE_NAME_2")]
    enum ParentError {
        #[error("first error")]
        #[sdk_error(code = 1)]
        NotForwarded(#[source] ChildError),

        #[error("nested error")]
        #[sdk_error(transparent)]
        Nested(#[source] ChildError),
    }

    #[derive(thiserror::Error, Debug, oasis_runtime_sdk_macros::Error)]
    enum ParentParentError {
        #[error("nested nested error")]
        #[sdk_error(transparent)]
        Nested(#[source] ParentError),
    }

    #[test]
    fn test_error_sources_1() {
        let err = ParentError::Nested(ChildError::Error1);
        let result = err.into_call_result();

        match result {
            CallResult::Failed {
                module,
                code,
                message: _,
            } => {
                assert_eq!(module, "test1");
                assert_eq!(code, 1);
            }
            _ => panic!("expected failed result, got: {:?}", result),
        }

        let err = ParentError::Nested(ChildError::Error2);
        let result = err.into_call_result();

        match result {
            CallResult::Failed {
                module,
                code,
                message: _,
            } => {
                assert_eq!(module, "test1");
                assert_eq!(code, 2);
            }
            _ => panic!("expected failed result, got: {:?}", result),
        }
    }

    #[test]
    fn test_error_sources_2() {
        let err = ParentError::NotForwarded(ChildError::Error1);
        let result = err.into_call_result();

        match result {
            CallResult::Failed {
                module,
                code,
                message: _,
            } => {
                assert_eq!(module, "test2");
                assert_eq!(code, 1);
            }
            _ => panic!("expected failed result, got: {:?}", result),
        }

        let err = ParentError::NotForwarded(ChildError::Error2);
        let result = err.into_call_result();

        match result {
            CallResult::Failed {
                module,
                code,
                message: _,
            } => {
                assert_eq!(module, "test2");
                assert_eq!(code, 1);
            }
            _ => panic!("expected failed result, got: {:?}", result),
        }
    }

    #[test]
    fn test_error_sources_3() {
        let err = ParentParentError::Nested(ParentError::Nested(ChildError::Error1));
        let result = err.into_call_result();

        match result {
            CallResult::Failed {
                module,
                code,
                message: _,
            } => {
                assert_eq!(module, "test1");
                assert_eq!(code, 1);
            }
            _ => panic!("expected failed result, got: {:?}", result),
        }
    }
}