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denoland-deno/core/error.rs
2022-08-11 11:57:20 +02:00

523 lines
16 KiB
Rust

// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
use crate::runtime::GetErrorClassFn;
use crate::runtime::JsRealm;
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 = JsRealm::state_from_scope(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, &error.to_string()).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.
#[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, 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::Value>>,
) -> 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_else(|| "".to_string());
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(&cause) {
None
} else {
seen.insert(cause);
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");
}
}