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
//! Format Ruby `Exception` backtraces.

use std::error;
use std::io;
use termcolor::{ColorSpec, WriteColor};

use crate::prelude::*;

/// Format an `Exception` backtrace into an [`io::Write`] suitable for
/// displaying in a Ruby REPL.
///
/// This backtrace has the same style and formatting as one returned from the
/// `irb` command in MRI.
///
/// # Examples
///
/// Executing the following Ruby code:
///
/// ```ruby
/// def fail; raise RuntimeError, "bang!"; end
/// fail
/// ```
///
/// Results in this stacktrace:
///
/// ```txt
/// Traceback (most recent call last):
///     2: from (airb):2
///     1: from (airb):1:in fail
/// RuntimeError (bang!)
/// ```
///
/// # Errors
///
/// If writing into the provided `out` writer fails, an error is returned.
pub fn format_repl_trace_into<W, E>(
    mut error: W,
    interp: &mut Artichoke,
    exc: &E,
) -> Result<(), Box<dyn error::Error>>
where
    W: io::Write + WriteColor,
    E: RubyException,
{
    // reset colors
    error.reset()?;

    // Format backtrace if present
    if let Some(backtrace) = exc.vm_backtrace(interp) {
        error.set_color(ColorSpec::new().set_bold(true))?;
        write!(error, "Traceback")?;
        error.reset()?;
        writeln!(error, " (most recent call last):")?;
        for (num, frame) in backtrace.into_iter().enumerate().rev() {
            write!(error, "\t{}: from ", num + 1)?;
            error.write_all(frame.as_slice())?;
            writeln!(error)?;
        }
    }

    // Format exception class and message
    error.set_color(ColorSpec::new().set_bold(true))?;
    write!(error, "{} (", exc.name())?;
    error.set_color(ColorSpec::new().set_bold(true).set_underline(true))?;
    error.write_all(&exc.message())?;
    error.set_color(ColorSpec::new().set_bold(true))?;
    writeln!(error, ")")?;

    // reset colors
    error.reset()?;

    Ok(())
}

/// Format an `Exception` backtrace into an [`io::Write`] suitable for
/// displaying in a Ruby CLI.
///
/// This backtrace has the same style and formatting as one returned from the
/// `ruby` command in MRI.
///
/// # Examples
///
/// Executing the following Ruby code:
///
/// ```ruby
/// def fail; raise RuntimeError, "bang!"; end
/// fail
/// ```
///
/// Results in this stacktrace:
///
/// ```txt
/// Traceback (most recent call last):
///     2: from -e:1
/// -e:1:in fail: bang! (RuntimeError)
/// ```
///
/// # Errors
///
/// If writing into the provided `out` writer fails, an error is returned.
pub fn format_cli_trace_into<W, E>(
    mut error: W,
    interp: &mut Artichoke,
    exc: &E,
) -> Result<(), Box<dyn error::Error>>
where
    W: io::Write + WriteColor,
    E: RubyException,
{
    // reset colors
    error.reset()?;

    let mut top = None;

    // Format backtrace if present
    if let Some(backtrace) = exc.vm_backtrace(interp) {
        error.set_color(ColorSpec::new().set_bold(true))?;
        write!(error, "Traceback")?;
        error.reset()?;
        writeln!(error, " (most recent call last):")?;
        let mut iter = backtrace.into_iter().enumerate();
        top = iter.next();
        for (num, frame) in iter.rev() {
            write!(error, "\t{}: from ", num + 1)?;
            error.write_all(frame.as_slice())?;
            writeln!(error)?;
        }
    }

    if let Some((_, frame)) = top {
        error.write_all(frame.as_slice())?;
        write!(error, ": ")?;
    }

    // Format exception class and message
    error.set_color(ColorSpec::new().set_bold(true))?;
    error.write_all(&exc.message())?;
    error.set_color(ColorSpec::new().set_bold(true))?;
    write!(error, " (")?;
    error.set_color(ColorSpec::new().set_bold(true).set_underline(true))?;
    write!(error, "{}", exc.name())?;
    error.set_color(ColorSpec::new().set_bold(true))?;
    writeln!(error, ")")?;

    // reset colors
    error.reset()?;

    Ok(())
}