deno.land / x / deno@v1.28.2 / core / error.rs
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use crate::runtime::GetErrorClassFn;use crate::runtime::JsRuntime;use crate::source_map::apply_source_map;use crate::source_map::get_source_line;use crate::url::Url;use anyhow::Error;use std::borrow::Cow;use std::collections::HashSet;use std::fmt;use std::fmt::Debug;use std::fmt::Display;use std::fmt::Formatter;
/// A generic wrapper that can encapsulate any concrete error type.// TODO(ry) Deprecate AnyError and encourage deno_core::anyhow::Error instead.pub type AnyError = anyhow::Error;
/// Creates a new error with a caller-specified error class name and message.pub fn custom_error( class: &'static str, message: impl Into<Cow<'static, str>>,) -> Error { CustomError { class, message: message.into(), } .into()}
pub fn generic_error(message: impl Into<Cow<'static, str>>) -> Error { custom_error("Error", message)}
pub fn type_error(message: impl Into<Cow<'static, str>>) -> Error { custom_error("TypeError", message)}
pub fn range_error(message: impl Into<Cow<'static, str>>) -> Error { custom_error("RangeError", message)}
pub fn invalid_hostname(hostname: &str) -> Error { type_error(format!("Invalid hostname: '{}'", hostname))}
pub fn uri_error(message: impl Into<Cow<'static, str>>) -> Error { custom_error("URIError", message)}
pub fn bad_resource(message: impl Into<Cow<'static, str>>) -> Error { custom_error("BadResource", message)}
pub fn bad_resource_id() -> Error { custom_error("BadResource", "Bad resource ID")}
pub fn not_supported() -> Error { custom_error("NotSupported", "The operation is not supported")}
pub fn resource_unavailable() -> Error { custom_error( "Busy", "Resource is unavailable because it is in use by a promise", )}
/// A simple error type that lets the creator specify both the error message and/// the error class name. This type is private; externally it only ever appears/// wrapped in an `anyhow::Error`. To retrieve the error class name from a wrapped/// `CustomError`, use the function `get_custom_error_class()`.#[derive(Debug)]struct CustomError { class: &'static str, message: Cow<'static, str>,}
impl Display for CustomError { fn fmt(&self, f: &mut Formatter) -> fmt::Result { f.write_str(&self.message) }}
impl std::error::Error for CustomError {}
/// If this error was crated with `custom_error()`, return the specified error/// class name. In all other cases this function returns `None`.pub fn get_custom_error_class(error: &Error) -> Option<&'static str> { error.downcast_ref::<CustomError>().map(|e| e.class)}
pub fn to_v8_error<'a>( scope: &mut v8::HandleScope<'a>, get_class: GetErrorClassFn, error: &Error,) -> v8::Local<'a, v8::Value> { let cb = JsRuntime::state(scope) .borrow() .js_build_custom_error_cb .clone() .expect("Custom error builder must be set"); let cb = cb.open(scope); let this = v8::undefined(scope).into(); let class = v8::String::new(scope, get_class(error)).unwrap(); let message = v8::String::new(scope, &format!("{:#}", error)).unwrap(); let mut args = vec![class.into(), message.into()]; if let Some(code) = crate::error_codes::get_error_code(error) { args.push(v8::String::new(scope, code).unwrap().into()); } let exception = cb .call(scope, this, &args) .expect("Custom error class must have a builder registered"); exception}
/// A `JsError` represents an exception coming from V8, with stack frames and/// line numbers. The deno_cli crate defines another `JsError` type, which wraps/// the one defined here, that adds source map support and colorful formatting./// When updating this struct, also update errors_are_equal_without_cause() in/// fmt_error.rs.#[derive(Debug, PartialEq, Clone, serde::Deserialize, serde::Serialize)]#[serde(rename_all = "camelCase")]pub struct JsError { pub name: Option<String>, pub message: Option<String>, pub stack: Option<String>, pub cause: Option<Box<JsError>>, pub exception_message: String, pub frames: Vec<JsStackFrame>, pub source_line: Option<String>, pub source_line_frame_index: Option<usize>, pub aggregated: Option<Vec<JsError>>,}
#[derive(Debug, Eq, PartialEq, Clone, serde::Deserialize, serde::Serialize)]#[serde(rename_all = "camelCase")]pub struct JsStackFrame { pub type_name: Option<String>, pub function_name: Option<String>, pub method_name: Option<String>, pub file_name: Option<String>, pub line_number: Option<i64>, pub column_number: Option<i64>, pub eval_origin: Option<String>, // Warning! isToplevel has inconsistent snake<>camel case, "typo" originates in v8: // https://source.chromium.org/search?q=isToplevel&sq=&ss=chromium%2Fchromium%2Fsrc:v8%2F #[serde(rename = "isToplevel")] pub is_top_level: Option<bool>, pub is_eval: bool, pub is_native: bool, pub is_constructor: bool, pub is_async: bool, pub is_promise_all: bool, pub promise_index: Option<i64>,}
impl JsStackFrame { pub fn from_location( file_name: Option<String>, line_number: Option<i64>, column_number: Option<i64>, ) -> Self { Self { type_name: None, function_name: None, method_name: None, file_name, line_number, column_number, eval_origin: None, is_top_level: None, is_eval: false, is_native: false, is_constructor: false, is_async: false, is_promise_all: false, promise_index: None, } }}
fn get_property<'a>( scope: &mut v8::HandleScope<'a>, object: v8::Local<v8::Object>, key: &str,) -> Option<v8::Local<'a, v8::Value>> { let key = v8::String::new(scope, key).unwrap(); object.get(scope, key.into())}
#[derive(Default, serde::Deserialize)]pub(crate) struct NativeJsError { pub name: Option<String>, pub message: Option<String>, // Warning! .stack is special so handled by itself // stack: Option<String>,}
impl JsError { pub fn from_v8_exception( scope: &mut v8::HandleScope, exception: v8::Local<v8::Value>, ) -> Self { Self::inner_from_v8_exception(scope, exception, Default::default()) }
fn inner_from_v8_exception<'a>( scope: &'a mut v8::HandleScope, exception: v8::Local<'a, v8::Value>, mut seen: HashSet<v8::Local<'a, v8::Object>>, ) -> Self { // Create a new HandleScope because we're creating a lot of new local // handles below. let scope = &mut v8::HandleScope::new(scope);
let msg = v8::Exception::create_message(scope, exception);
let mut exception_message = None; let state_rc = JsRuntime::state(scope);
let js_format_exception_cb = state_rc.borrow().js_format_exception_cb.clone(); if let Some(format_exception_cb) = js_format_exception_cb { let format_exception_cb = format_exception_cb.open(scope); let this = v8::undefined(scope).into(); let formatted = format_exception_cb.call(scope, this, &[exception]); if let Some(formatted) = formatted { if formatted.is_string() { exception_message = Some(formatted.to_rust_string_lossy(scope)); } } }
if is_instance_of_error(scope, exception) { // The exception is a JS Error object. let exception: v8::Local<v8::Object> = exception.try_into().unwrap(); let cause = get_property(scope, exception, "cause"); let e: NativeJsError = serde_v8::from_v8(scope, exception.into()).unwrap_or_default(); // Get the message by formatting error.name and error.message. let name = e.name.clone().unwrap_or_else(|| "Error".to_string()); let message_prop = e.message.clone().unwrap_or_default(); let exception_message = exception_message.unwrap_or_else(|| { if !name.is_empty() && !message_prop.is_empty() { format!("Uncaught {}: {}", name, message_prop) } else if !name.is_empty() { format!("Uncaught {}", name) } else if !message_prop.is_empty() { format!("Uncaught {}", message_prop) } else { "Uncaught".to_string() } }); let cause = cause.and_then(|cause| { if cause.is_undefined() || seen.contains(&exception) { None } else { seen.insert(exception); Some(Box::new(JsError::inner_from_v8_exception( scope, cause, seen, ))) } });
// Access error.stack to ensure that prepareStackTrace() has been called. // This should populate error.__callSiteEvals. let stack = get_property(scope, exception, "stack"); let stack: Option<v8::Local<v8::String>> = stack.and_then(|s| s.try_into().ok()); let stack = stack.map(|s| s.to_rust_string_lossy(scope));
// Read an array of structured frames from error.__callSiteEvals. let frames_v8 = get_property(scope, exception, "__callSiteEvals"); // Ignore non-array values let frames_v8: Option<v8::Local<v8::Array>> = frames_v8.and_then(|a| a.try_into().ok());
// Convert them into Vec<JsStackFrame> let mut frames: Vec<JsStackFrame> = match frames_v8 { Some(frames_v8) => serde_v8::from_v8(scope, frames_v8.into()).unwrap(), None => vec![], };
let mut source_line = None; let mut source_line_frame_index = None; { let state = &mut *state_rc.borrow_mut();
// When the stack frame array is empty, but the source location given by // (script_resource_name, line_number, start_column + 1) exists, this is // likely a syntax error. For the sake of formatting we treat it like it // was given as a single stack frame. if frames.is_empty() { let script_resource_name = msg .get_script_resource_name(scope) .and_then(|v| v8::Local::<v8::String>::try_from(v).ok()) .map(|v| v.to_rust_string_lossy(scope)); let line_number: Option<i64> = msg.get_line_number(scope).and_then(|v| v.try_into().ok()); let column_number: Option<i64> = msg.get_start_column().try_into().ok(); if let (Some(f), Some(l), Some(c)) = (script_resource_name, line_number, column_number) { // V8's column numbers are 0-based, we want 1-based. let c = c + 1; if let Some(source_map_getter) = &state.source_map_getter { let (f, l, c) = apply_source_map( f, l, c, &mut state.source_map_cache, source_map_getter.as_ref(), ); frames = vec![JsStackFrame::from_location(Some(f), Some(l), Some(c))]; } else { frames = vec![JsStackFrame::from_location(Some(f), Some(l), Some(c))]; } } }
if let Some(source_map_getter) = &state.source_map_getter { for (i, frame) in frames.iter().enumerate() { if let (Some(file_name), Some(line_number)) = (&frame.file_name, frame.line_number) { if !file_name.trim_start_matches('[').starts_with("deno:") { // Source lookup expects a 0-based line number, ours are 1-based. source_line = get_source_line( file_name, line_number, &mut state.source_map_cache, source_map_getter.as_ref(), ); source_line_frame_index = Some(i); break; } } } } else if let Some(frame) = frames.first() { if let Some(file_name) = &frame.file_name { if !file_name.trim_start_matches('[').starts_with("deno:") { source_line = msg .get_source_line(scope) .map(|v| v.to_rust_string_lossy(scope)); source_line_frame_index = Some(0); } } } }
// Read an array of stored errors, this is only defined for `AggregateError` let aggregated_errors = get_property(scope, exception, "errors"); let aggregated_errors: Option<v8::Local<v8::Array>> = aggregated_errors.and_then(|a| a.try_into().ok());
let mut aggregated: Option<Vec<JsError>> = None;
if let Some(errors) = aggregated_errors { if errors.length() > 0 { let mut agg = vec![]; for i in 0..errors.length() { let error = errors.get_index(scope, i).unwrap(); let js_error = Self::from_v8_exception(scope, error); agg.push(js_error); } aggregated = Some(agg); } }
Self { name: e.name, message: e.message, exception_message, cause, source_line, source_line_frame_index, frames, stack, aggregated, } } else { let exception_message = exception_message .unwrap_or_else(|| msg.get(scope).to_rust_string_lossy(scope)); // The exception is not a JS Error object. // Get the message given by V8::Exception::create_message(), and provide // empty frames. Self { name: None, message: None, exception_message, cause: None, source_line: None, source_line_frame_index: None, frames: vec![], stack: None, aggregated: None, } } }}
impl std::error::Error for JsError {}
fn format_source_loc( file_name: &str, line_number: i64, column_number: i64,) -> String { let line_number = line_number; let column_number = column_number; format!("{}:{}:{}", file_name, line_number, column_number)}
impl Display for JsError { fn fmt(&self, f: &mut Formatter) -> fmt::Result { if let Some(stack) = &self.stack { let stack_lines = stack.lines(); if stack_lines.count() > 1 { return write!(f, "{}", stack); } } write!(f, "{}", self.exception_message)?; let frame = self.frames.first(); if let Some(frame) = frame { if let (Some(f_), Some(l), Some(c)) = (&frame.file_name, frame.line_number, frame.column_number) { let source_loc = format_source_loc(f_, l, c); write!(f, "\n at {}", source_loc)?; } } Ok(()) }}
// TODO(piscisaureus): rusty_v8 should implement the Error trait on// values of type v8::Global<T>.pub(crate) fn to_v8_type_error( scope: &mut v8::HandleScope, err: Error,) -> v8::Global<v8::Value> { let message = err.to_string(); let message = v8::String::new(scope, &message).unwrap(); let exception = v8::Exception::type_error(scope, message); v8::Global::new(scope, exception)}
/// Implements `value instanceof primordials.Error` in JS. Similar to/// `Value::is_native_error()` but more closely matches the semantics/// of `instanceof`. `Value::is_native_error()` also checks for static class/// inheritance rather than just scanning the prototype chain, which doesn't/// work with our WebIDL implementation of `DOMException`.pub(crate) fn is_instance_of_error<'s>( scope: &mut v8::HandleScope<'s>, value: v8::Local<v8::Value>,) -> bool { if !value.is_object() { return false; } let message = v8::String::empty(scope); let error_prototype = v8::Exception::error(scope, message) .to_object(scope) .unwrap() .get_prototype(scope) .unwrap(); let mut maybe_prototype = value.to_object(scope).unwrap().get_prototype(scope); while let Some(prototype) = maybe_prototype { if !prototype.is_object() { return false; } if prototype.strict_equals(error_prototype) { return true; } maybe_prototype = prototype .to_object(scope) .and_then(|o| o.get_prototype(scope)); } false}
const DATA_URL_ABBREV_THRESHOLD: usize = 150;
pub fn format_file_name(file_name: &str) -> String { abbrev_file_name(file_name).unwrap_or_else(|| file_name.to_string())}
fn abbrev_file_name(file_name: &str) -> Option<String> { if file_name.len() <= DATA_URL_ABBREV_THRESHOLD { return None; } let url = Url::parse(file_name).ok()?; if url.scheme() != "data" { return None; } let (head, tail) = url.path().split_once(',')?; let len = tail.len(); let start = tail.get(0..20)?; let end = tail.get(len - 20..)?; Some(format!("{}:{},{}......{}", url.scheme(), head, start, end))}
#[cfg(test)]mod tests { use super::*;
#[test] fn test_bad_resource() { let err = bad_resource("Resource has been closed"); assert_eq!(err.to_string(), "Resource has been closed"); }
#[test] fn test_bad_resource_id() { let err = bad_resource_id(); assert_eq!(err.to_string(), "Bad resource ID"); }}
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