rustyscript/

error.rs

//! Contains the error type for the runtime
//! And some associated utilities
use std::path::PathBuf;

use deno_core::error::CoreErrorKind;
use thiserror::Error;

use crate::Module;

/// Options for [`Error::as_highlighted`]
#[allow(clippy::struct_excessive_bools)]
#[derive(Debug, Clone)]
pub struct ErrorFormattingOptions {
    /// Include the filename in the output
    /// Appears on the first line
    pub include_filename: bool,

    /// Include the line number in the output
    /// Appears on the first line
    pub include_line_number: bool,

    /// Include the column number in the output
    /// Appears on the first line
    pub include_column_number: bool,

    /// Hide the current directory in the output
    pub hide_current_directory: bool,

    /// Used to set the directory to remove, in cases where the runtime and system CWD differ
    pub current_directory: Option<PathBuf>,
}
impl Default for ErrorFormattingOptions {
    fn default() -> Self {
        Self {
            include_filename: true,
            include_line_number: true,
            include_column_number: true,

            hide_current_directory: false,
            current_directory: None,
        }
    }
}

/// Represents the errors that can occur during execution of a module
#[derive(Error, Debug, Clone, serde::Serialize, serde::Deserialize, deno_error::JsError)]
pub enum Error {
    /// Triggers when a module has no stated entrypoint (default or registered at runtime)
    #[class(generic)]
    #[error("{0} has no entrypoint. Register one, or add a default to the runtime")]
    MissingEntrypoint(Module),

    /// Triggers when an attempt to find a value by name fails
    #[class(generic)]
    #[error("{0} could not be found in global, or module exports")]
    ValueNotFound(String),

    /// Triggers when attempting to call a value as a function
    #[class(generic)]
    #[error("{0} is not a function")]
    ValueNotCallable(String),

    /// Triggers when a string could not be encoded for v8
    #[class(generic)]
    #[error("{0} could not be encoded as a v8 value")]
    V8Encoding(String),

    /// Triggers when a result could not be deserialize to the requested type
    #[class(generic)]
    #[error("value could not be deserialized: {0}")]
    JsonDecode(String),

    /// Triggers when a module could not be loaded from the filesystem
    #[class(generic)]
    #[error("{0}")]
    ModuleNotFound(String),

    /// Triggers when attempting to use a worker that has already been shutdown
    #[class(generic)]
    #[error("This worker has been destroyed")]
    WorkerHasStopped,

    /// Triggers on runtime issues during execution of a module
    #[class(generic)]
    #[error("{0}")]
    Runtime(String),

    /// Runtime error we successfully downcast
    #[class(generic)]
    #[error("{0}")]
    JsError(Box<deno_core::error::JsError>),

    /// Triggers when a module times out before finishing
    #[class(generic)]
    #[error("Module timed out: {0}")]
    Timeout(String),

    /// Triggers when the heap (via `max_heap_size`) is exhausted during execution
    #[class(generic)]
    #[error("Heap exhausted")]
    HeapExhausted,
}

impl From<deno_core::error::JsError> for Error {
    fn from(err: deno_core::error::JsError) -> Self {
        Self::JsError(Box::new(err))
    }
}

impl Error {
    /// Formats an error for display in a terminal
    /// If the error is a `JsError`, it will attempt to highlight the source line
    /// in this format:
    /// ```text
    /// | let x = 1 + 2
    /// |       ^
    /// = Unexpected token '='
    /// ```
    ///
    /// Otherwise, it will just display the error message normally
    #[must_use]
    pub fn as_highlighted(&self, options: ErrorFormattingOptions) -> String {
        let mut e = if let Error::JsError(e) = self {
            // Extract basic information about position
            let (filename, row, col) = match e.frames.first() {
                Some(f) => (
                    match &f.file_name {
                        Some(f) if f.is_empty() => None::<&str>,
                        Some(f) => Some(f.as_ref()),
                        None => None,
                    },
                    usize::try_from(f.line_number.unwrap_or(1)).unwrap_or_default(),
                    usize::try_from(f.column_number.unwrap_or(1)).unwrap_or_default(),
                ),
                None => (None, 1, 1),
            };

            let mut line = e.source_line.as_ref().map(|s| s.trim_end());
            let col = col - 1;

            // Get at most 50 characters, centered on column_number
            let mut padding = String::new();
            match line {
                None => {}
                Some(s) => {
                    let (start, end) = if s.len() < 50 {
                        (0, s.len())
                    } else if col < 25 {
                        (0, 50)
                    } else if col > s.len() - 25 {
                        (s.len() - 50, s.len())
                    } else {
                        (col - 25, col + 25)
                    };

                    line = Some(s.get(start..end).unwrap_or(s));
                    padding = " ".repeat(col - start);
                }
            }

            let msg_lines = e.exception_message.split('\n').collect::<Vec<_>>();

            //
            // Format all the parts using the options
            //

            let line_number_part = if options.include_line_number {
                format!("{row}:")
            } else {
                String::new()
            };

            let col_number_part = if options.include_column_number {
                format!("{col}:")
            } else {
                String::new()
            };

            let source_line_part = match line {
                Some(s) => format!("| {s}\n| {padding}^\n"),
                None => String::new(),
            };

            let msg_part = msg_lines
                .into_iter()
                .map(|l| format!("= {l}"))
                .collect::<Vec<_>>()
                .join("\n");

            let position_part = format!("{line_number_part}{col_number_part}");
            let position_part = match filename {
                None if position_part.is_empty() => String::new(),
                Some(f) if options.include_filename => format!("At {f}:{position_part}\n"),
                _ => format!("At {position_part}\n"),
            };

            // Combine all the parts
            format!("{position_part}{source_line_part}{msg_part}",)
        } else {
            self.to_string()
        };

        //
        // Hide directory
        if options.hide_current_directory {
            let dir = options.current_directory.or(std::env::current_dir().ok());
            if let Some(dir) = dir {
                let dir = dir.to_string_lossy().replace('\\', "/");
                e = e.replace(&dir, "");
                e = e.replace("file:////", "file:///");
            }
        }

        e
    }
}

#[macro_use]
mod error_macro {
    /// Maps one error type to another
    macro_rules! map_error {
        ($source_error:path, $impl:expr) => {
            impl From<$source_error> for Error {
                fn from(e: $source_error) -> Self {
                    let fmt: &dyn Fn($source_error) -> Self = &$impl;
                    fmt(e)
                }
            }
        };
    }
}

#[cfg(feature = "node_experimental")]
map_error!(node_resolver::analyze::TranslateCjsToEsmError, |e| {
    Error::Runtime(e.to_string())
});

map_error!(deno_ast::TranspileError, |e| Error::Runtime(e.to_string()));
map_error!(deno_core::error::CoreError, |e| {
    let e = e.into_kind();
    match e {
        CoreErrorKind::Js(js_error) => Error::JsError(Box::new(js_error)),
        _ => Error::Runtime(e.to_string()),
    }
});
map_error!(std::cell::BorrowMutError, |e| Error::Runtime(e.to_string()));
map_error!(std::io::Error, |e| Error::ModuleNotFound(e.to_string()));
map_error!(deno_core::v8::DataError, |e| Error::Runtime(e.to_string()));
map_error!(deno_core::ModuleResolutionError, |e| Error::Runtime(
    e.to_string()
));
map_error!(deno_core::url::ParseError, |e| Error::Runtime(
    e.to_string()
));
map_error!(deno_core::serde_json::Error, |e| Error::JsonDecode(
    e.to_string()
));
map_error!(deno_core::serde_v8::Error, |e| Error::JsonDecode(
    e.to_string()
));

map_error!(deno_core::anyhow::Error, |e| {
    Error::Runtime(e.to_string())
});

map_error!(tokio::time::error::Elapsed, |e| {
    Error::Timeout(e.to_string())
});
map_error!(tokio::task::JoinError, |e| {
    Error::Timeout(e.to_string())
});
map_error!(deno_core::futures::channel::oneshot::Canceled, |e| {
    Error::Timeout(e.to_string())
});

#[cfg(feature = "broadcast_channel")]
map_error!(deno_broadcast_channel::BroadcastChannelError, |e| {
    Error::Runtime(e.to_string())
});

#[cfg(test)]
mod test {
    use crate::{error::ErrorFormattingOptions, Module, Runtime, RuntimeOptions, Undefined};

    #[test]
    #[rustfmt::skip]
    fn test_highlights() {
        let mut runtime = Runtime::new(RuntimeOptions::default()).unwrap();

        let e = runtime.eval::<Undefined>("1+1;\n1 + x").unwrap_err().as_highlighted(ErrorFormattingOptions::default());
        assert_eq!(e, concat!(
            "At 2:4:\n",
            "= Uncaught ReferenceError: x is not defined"
        ));

        let module = Module::new("test.js", "1+1;\n1 + x");
        let e = runtime.load_module(&module).unwrap_err().as_highlighted(ErrorFormattingOptions {
            include_filename: false,
            ..Default::default()
        });
        assert_eq!(e, concat!(
            "At 2:4:\n",
            "| 1 + x\n",
            "|     ^\n",
            "= Uncaught (in promise) ReferenceError: x is not defined"
        ));

        let module = Module::new("test.js", "1+1;\n1 + x");
        let e = runtime.load_module(&module).unwrap_err().as_highlighted(ErrorFormattingOptions {
            hide_current_directory: true,
            ..Default::default()
        });
        assert_eq!(e, concat!(
            "At file:///test.js:2:4:\n",
            "| 1 + x\n",
            "|     ^\n",
            "= Uncaught (in promise) ReferenceError: x is not defined"
        ));
    }
}