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

use std::fmt::Display;
use thiserror::*;

/// The termwiz Error type encapsulates a range of internal
/// errors in an opaque manner.  You can use the `source`
/// method to reach the underlying errors if
/// necessary, but it is not expected that most code will
/// need to do so.  Please file an issue if you've got a
/// usecase for this!
#[derive(Error, Debug)]
#[error(transparent)]
pub struct Error(pub(crate) InternalError);

/// A Result whose error type is a termwiz Error
pub type Result<T> = std::result::Result<T, Error>;

impl<E> From<E> for Error
where
    E: Into<InternalError>,
{
    fn from(err: E) -> Self {
        Self(err.into())
    }
}

/// This enum encapsulates the various errors that can be
/// mapped into the termwiz Error type.
/// The intent is that this is effectively private to termwiz
/// itself, but since Rust doesn't allow enums with private
/// variants, we're dancing around with a newtype of an enum
/// and hiding it from the docs.
#[derive(Error, Debug)]
#[non_exhaustive]
#[doc(hidden)]
pub enum InternalError {
    #[error(transparent)]
    Fmt(#[from] std::fmt::Error),

    #[error(transparent)]
    Io(#[from] std::io::Error),

    #[error(transparent)]
    Regex(#[from] regex::Error),

    #[error(transparent)]
    FromUtf8(#[from] std::string::FromUtf8Error),

    #[error(transparent)]
    Utf8(#[from] std::str::Utf8Error),

    #[error(transparent)]
    Base64(#[from] base64::DecodeError),

    #[error(transparent)]
    ParseFloat(#[from] std::num::ParseFloatError),

    #[error(transparent)]
    ParseInt(#[from] std::num::ParseIntError),

    #[error(transparent)]
    FloatIsNan(#[from] ordered_float::FloatIsNan),

    #[error("{0}")]
    StringErr(#[from] StringWrap),

    #[error(transparent)]
    Anyhow(#[from] anyhow::Error),

    #[error(transparent)]
    Terminfo(#[from] terminfo::Error),

    #[error(transparent)]
    FileDescriptor(#[from] filedescriptor::Error),

    #[error("{}", .context)]
    Context {
        context: String,
        source: Box<dyn std::error::Error + Send + Sync + 'static>,
    },
}

impl From<String> for InternalError {
    fn from(s: String) -> Self {
        InternalError::StringErr(StringWrap(s))
    }
}

#[derive(Error, Debug)]
#[doc(hidden)]
#[error("{0}")]
pub struct StringWrap(pub String);

#[macro_export]
macro_rules! format_err {
    ($msg:literal $(,)?) => {
        return $crate::error::Error::from($crate::error::StringWrap($msg.to_string()))
    };
    ($err:expr $(,)?) => {
        return $crate::error::Error::from($crate::error::StringWrap(format!($err)))
    };
    ($fmt:expr, $($arg:tt)*) => {
        return $crate::error::Error::from($crate::error::StringWrap(format!($fmt, $($arg)*)))
    };
}

#[macro_export]
macro_rules! bail {
    ($msg:literal $(,)?) => {
        return Err($crate::error::StringWrap($msg.to_string()).into())
    };
    ($err:expr $(,)?) => {
        return Err($crate::error::StringWrap(format!($err)).into())
    };
    ($fmt:expr, $($arg:tt)*) => {
        return Err($crate::error::StringWrap(format!($fmt, $($arg)*)).into())
    };
}

#[macro_export]
macro_rules! ensure {
    ($cond:expr, $msg:literal $(,)?) => {
        if !$cond {
            return Err($crate::error::StringWrap(format!($msg)).into());
        }
    };
    ($cond:expr, $err:expr $(,)?) => {
        if !$cond {
            return Err($crate::error::StringWrap(format!($err)).into());
        }
    };
    ($cond:expr, $fmt:expr, $($arg:tt)*) => {
        if !$cond {
            return Err($crate::error::StringWrap(format!($fmt, $($arg)*)).into());
        }
    };
}

/// This trait allows extending the Result type so that it can create a
/// `termwiz::Error` that wraps an underlying other error and provide
/// additional context on that error.
pub trait Context<T, E> {
    /// Wrap the error value with additional context.
    fn context<C>(self, context: C) -> Result<T>
    where
        C: Display + Send + Sync + 'static;

    /// Wrap the error value with additional context that is evaluated lazily
    /// only once an error does occur.
    fn with_context<C, F>(self, f: F) -> Result<T>
    where
        C: Display + Send + Sync + 'static,
        F: FnOnce() -> C;
}

impl<T, E> Context<T, E> for std::result::Result<T, E>
where
    E: std::error::Error + Send + Sync + 'static,
{
    fn context<C>(self, context: C) -> Result<T>
    where
        C: Display + Send + Sync + 'static,
    {
        self.map_err(|error| {
            Error(InternalError::Context {
                context: context.to_string(),
                source: Box::new(error),
            })
        })
    }

    fn with_context<C, F>(self, context: F) -> Result<T>
    where
        C: Display + Send + Sync + 'static,
        F: FnOnce() -> C,
    {
        self.map_err(|error| {
            Error(InternalError::Context {
                context: context().to_string(),
                source: Box::new(error),
            })
        })
    }
}