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

// Copyright Materialize, Inc. and contributors. All rights reserved.
//
// Use of this software is governed by the Business Source License
// included in the LICENSE file.
//
// As of the Change Date specified in that file, in accordance with
// the Business Source License, use of this software will be governed
// by the Apache License, Version 2.0.

//! Error handling.
//!
//! Errors inside of the testdrive library are represented as an
//! `anyhow::Error`. As the error bubbles up the stack, it may be upgraded to a
//! `PosError`, which attaches source code position information. The position
//! information tracked by a `PosError` uses a parser-specific representation
//! that is not human-readable, so `PosError`s are upgraded to `Error`s before
//! they are returned externally.

use std::fmt::{self, Write as _};
use std::io::{self, Write};
use std::path::{Path, PathBuf};

use atty::Stream;
use mz_ore::error::ErrorExt;
use termcolor::{Color, ColorChoice, ColorSpec, StandardStream, WriteColor};

/// An error produced when parsing or executing a testdrive script.
///
/// Errors are optionally associated with a location in a testdrive script. When
/// printed with the [`Error::print_stderr`] method, the location of the error
/// along with a snippet of the source code at that location will be printed
/// alongside the error message.
pub struct Error {
    source: anyhow::Error,
    location: Option<ErrorLocation>,
}

impl Error {
    pub(crate) fn new(source: anyhow::Error, location: Option<ErrorLocation>) -> Self {
        Error { source, location }
    }

    /// Prints the error to `stderr`, with coloring if the terminal supports it.
    pub fn print_stderr(&self) -> io::Result<()> {
        let color_choice = if atty::is(Stream::Stderr) {
            ColorChoice::Auto
        } else {
            ColorChoice::Never
        };
        let mut stderr = StandardStream::stderr(color_choice);
        eprintln!("^^^ +++");
        match &self.location {
            Some(location) => {
                let mut color_spec = ColorSpec::new();
                color_spec.set_bold(true);
                stderr.set_color(&color_spec)?;
                if let Some(filename) = &location.filename {
                    write!(
                        &mut stderr,
                        "{}:{}:{}: ",
                        filename.display(),
                        location.line,
                        location.col
                    )?;
                } else {
                    write!(&mut stderr, "{}:{}: ", location.line, location.col)?;
                }
                write_error_heading(&mut stderr, &color_spec)?;
                writeln!(&mut stderr, "{}", self.source.display_with_causes())?;
                color_spec.set_bold(false);
                stderr.set_color(&color_spec)?;
                write!(&mut stderr, "{}", location.snippet)?;
                writeln!(&mut stderr, "{}^", " ".repeat(location.col - 1))?;
            }
            None => {
                let color_spec = ColorSpec::new();
                write_error_heading(&mut stderr, &color_spec)?;
                writeln!(&mut stderr, "{}", self.source.display_with_causes())?;
            }
        }
        std::io::stderr().flush()
    }
}

impl fmt::Display for Error {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}", self.source.display_with_causes())
    }
}

fn write_error_heading(stream: &mut StandardStream, color_spec: &ColorSpec) -> io::Result<()> {
    stream.set_color(color_spec.clone().set_fg(Some(Color::Red)))?;
    write!(stream, "error: ")?;
    stream.set_color(color_spec)
}

impl From<anyhow::Error> for Error {
    fn from(source: anyhow::Error) -> Error {
        Error {
            source,
            location: None,
        }
    }
}

pub(crate) struct ErrorLocation {
    filename: Option<PathBuf>,
    snippet: String,
    line: usize,
    col: usize,
}

impl ErrorLocation {
    pub(crate) fn new(
        filename: Option<&Path>,
        contents: &str,
        line: usize,
        col: usize,
    ) -> ErrorLocation {
        let mut snippet = String::new();
        writeln!(&mut snippet, "     |").unwrap();
        for (i, l) in contents.lines().enumerate() {
            let l_lc = l.to_lowercase();
            if i >= line {
                break;
            } else if l_lc.contains("postgres-") || l_lc.contains("secret") || l_lc.contains("url")
            {
                writeln!(
                    &mut snippet,
                    "{:4} | {} ... [rest of line truncated for security]",
                    i + 1,
                    l.get(0..20).unwrap_or(l)
                )
                .unwrap();
            } else if i + 2 >= line {
                writeln!(&mut snippet, "{:4} | {}", i + 1, l).unwrap();
            }
        }
        write!(&mut snippet, "     | ").unwrap();

        ErrorLocation {
            filename: filename.map(|f| f.to_path_buf()),
            snippet,
            line,
            col,
        }
    }
}

pub(crate) struct PosError {
    pub(crate) source: anyhow::Error,
    pub(crate) pos: Option<usize>,
}

impl PosError {
    pub(crate) fn new(source: anyhow::Error, pos: usize) -> PosError {
        PosError {
            source,
            pos: Some(pos),
        }
    }
}

impl From<anyhow::Error> for PosError {
    fn from(source: anyhow::Error) -> PosError {
        PosError { source, pos: None }
    }
}