<commit_before>/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

//! Conversions of Rust values to and from `JSVal`.
//!
//! | IDL type                | Argument type   | Return type    |
//! |-------------------------|-----------------|----------------|
//! | any                     | `JSVal`                          |
//! | boolean                 | `bool`                           |
//! | byte                    | `i8`                             |
//! | octet                   | `u8`                             |
//! | short                   | `i16`                            |
//! | unsigned short          | `u16`                            |
//! | long                    | `i32`                            |
//! | unsigned long           | `u32`                            |
//! | long long               | `i64`                            |
//! | unsigned long long      | `u64`                            |
//! | float                   | `f32`                            |
//! | double                  | `f64`                            |
//! | DOMString               | `DOMString`                      |
//! | USVString               | `USVString`                      |
//! | ByteString              | `ByteString`                     |
//! | object                  | `*mut JSObject`                  |
//! | interface types         | `JSRef<T>`      | `Temporary<T>` |
//! | dictionary types        | `&T`            | *unsupported*  |
//! | enumeration types       | `T`                              |
//! | callback function types | `T`                              |
//! | nullable types          | `Option<T>`                      |
//! | sequences               | `Vec<T>`                         |
//! | union types             | `T`                              |

use dom::bindings::codegen::PrototypeList;
use dom::bindings::js::{JSRef, Root, Unrooted};
use dom::bindings::str::{ByteString, USVString};
use dom::bindings::utils::{Reflectable, Reflector, DOMClass};
use util::str::DOMString;

use js;
use js::glue::{RUST_JSID_TO_STRING, RUST_JSID_IS_STRING};
use js::glue::RUST_JS_NumberValue;
use js::jsapi::{JSBool, JSContext, JSObject, JSString, jsid};
use js::jsapi::{JS_ValueToUint64, JS_ValueToInt64};
use js::jsapi::{JS_ValueToECMAUint32, JS_ValueToECMAInt32};
use js::jsapi::{JS_ValueToUint16, JS_ValueToNumber, JS_ValueToBoolean};
use js::jsapi::{JS_ValueToString, JS_GetStringCharsAndLength};
use js::jsapi::{JS_NewUCStringCopyN, JS_NewStringCopyN};
use js::jsapi::{JS_WrapValue};
use js::jsapi::{JSClass, JS_GetClass};
use js::jsval::JSVal;
use js::jsval::{UndefinedValue, NullValue, BooleanValue, Int32Value, UInt32Value};
use js::jsval::{StringValue, ObjectValue, ObjectOrNullValue};

use libc;
use std::borrow::ToOwned;
use std::default;
use std::slice;

/// A trait to retrieve the constants necessary to check if a `JSObject`
/// implements a given interface.
pub trait IDLInterface {
    /// Returns the prototype ID.
    fn get_prototype_id() -> PrototypeList::ID;
    /// Returns the prototype depth, i.e., the number of interfaces this
    /// interface inherits from.
    fn get_prototype_depth() -> usize;
}

/// A trait to convert Rust types to `JSVal`s.
pub trait ToJSValConvertible {
    /// Convert `self` to a `JSVal`. JSAPI failure causes a task failure.
    fn to_jsval(&self, cx: *mut JSContext) -> JSVal;
}

/// A trait to convert `JSVal`s to Rust types.
pub trait FromJSValConvertible {
    type Config;
    /// Convert `val` to type `Self`.
    /// Optional configuration of type `T` can be passed as the `option`
    /// argument.
    /// If it returns `Err(())`, a JSAPI exception is pending.
    fn from_jsval(cx: *mut JSContext, val: JSVal, option: Self::Config) -> Result<Self, ()>;
}


impl ToJSValConvertible for () {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        UndefinedValue()
    }
}

impl ToJSValConvertible for JSVal {
    fn to_jsval(&self, cx: *mut JSContext) -> JSVal {
        let mut value = *self;
        if unsafe { JS_WrapValue(cx, &mut value) } == 0 {
            panic!("JS_WrapValue failed.");
        }
        value
    }
}

unsafe fn convert_from_jsval<T: default::Default>(
    cx: *mut JSContext, value: JSVal,
    convert_fn: unsafe extern "C" fn(*mut JSContext, JSVal, *mut T) -> JSBool) -> Result<T, ()> {
    let mut ret = default::Default::default();
    if convert_fn(cx, value, &mut ret) == 0 {
        Err(())
    } else {
        Ok(ret)
    }
}


impl ToJSValConvertible for bool {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        BooleanValue(*self)
    }
}

impl FromJSValConvertible for bool {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<bool, ()> {
        let result = unsafe { convert_from_jsval(cx, val, JS_ValueToBoolean) };
        result.map(|b| b != 0)
    }
}

impl ToJSValConvertible for i8 {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        Int32Value(*self as i32)
    }
}

impl FromJSValConvertible for i8 {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<i8, ()> {
        let result = unsafe { convert_from_jsval(cx, val, JS_ValueToECMAInt32) };
        result.map(|v| v as i8)
    }
}

impl ToJSValConvertible for u8 {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        Int32Value(*self as i32)
    }
}

impl FromJSValConvertible for u8 {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<u8, ()> {
        let result = unsafe { convert_from_jsval(cx, val, JS_ValueToECMAInt32) };
        result.map(|v| v as u8)
    }
}

impl ToJSValConvertible for i16 {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        Int32Value(*self as i32)
    }
}

impl FromJSValConvertible for i16 {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<i16, ()> {
        let result = unsafe { convert_from_jsval(cx, val, JS_ValueToECMAInt32) };
        result.map(|v| v as i16)
    }
}

impl ToJSValConvertible for u16 {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        Int32Value(*self as i32)
    }
}

impl FromJSValConvertible for u16 {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<u16, ()> {
        unsafe { convert_from_jsval(cx, val, JS_ValueToUint16) }
    }
}

impl ToJSValConvertible for i32 {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        Int32Value(*self)
    }
}

impl FromJSValConvertible for i32 {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<i32, ()> {
        unsafe { convert_from_jsval(cx, val, JS_ValueToECMAInt32) }
    }
}

impl ToJSValConvertible for u32 {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        UInt32Value(*self)
    }
}

impl FromJSValConvertible for u32 {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<u32, ()> {
        unsafe { convert_from_jsval(cx, val, JS_ValueToECMAUint32) }
    }
}

impl ToJSValConvertible for i64 {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        unsafe {
            RUST_JS_NumberValue(*self as f64)
        }
    }
}

impl FromJSValConvertible for i64 {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<i64, ()> {
        unsafe { convert_from_jsval(cx, val, JS_ValueToInt64) }
    }
}

impl ToJSValConvertible for u64 {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        unsafe {
            RUST_JS_NumberValue(*self as f64)
        }
    }
}

impl FromJSValConvertible for u64 {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<u64, ()> {
        unsafe { convert_from_jsval(cx, val, JS_ValueToUint64) }
    }
}

impl ToJSValConvertible for f32 {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        unsafe {
            RUST_JS_NumberValue(*self as f64)
        }
    }
}

impl FromJSValConvertible for f32 {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<f32, ()> {
        let result = unsafe { convert_from_jsval(cx, val, JS_ValueToNumber) };
        result.map(|f| f as f32)
    }
}

impl ToJSValConvertible for f64 {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        unsafe {
            RUST_JS_NumberValue(*self)
        }
    }
}

impl FromJSValConvertible for f64 {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<f64, ()> {
        unsafe { convert_from_jsval(cx, val, JS_ValueToNumber) }
    }
}

impl ToJSValConvertible for str {
    fn to_jsval(&self, cx: *mut JSContext) -> JSVal {
        unsafe {
            let string_utf16: Vec<u16> = self.utf16_units().collect();
            let jsstr = JS_NewUCStringCopyN(cx, string_utf16.as_ptr(), string_utf16.len() as libc::size_t);
            if jsstr.is_null() {
                panic!("JS_NewUCStringCopyN failed");
            }
            StringValue(&*jsstr)
        }
    }
}

impl ToJSValConvertible for DOMString {
    fn to_jsval(&self, cx: *mut JSContext) -> JSVal {
        self.as_slice().to_jsval(cx)
    }
}

/// Behavior for stringification of `JSVal`s.
#[derive(PartialEq)]
pub enum StringificationBehavior {
    /// Convert `null` to the string `"null"`.
    Default,
    /// Convert `null` to the empty string.
    Empty,
}

impl default::Default for StringificationBehavior {
    fn default() -> StringificationBehavior {
        StringificationBehavior::Default
    }
}

/// Convert the given `JSString` to a `DOMString`. Fails if the string does not
/// contain valid UTF-16.
pub fn jsstring_to_str(cx: *mut JSContext, s: *mut JSString) -> DOMString {
    unsafe {
        let mut length = 0;
        let chars = JS_GetStringCharsAndLength(cx, s, &mut length);
        let char_vec = slice::from_raw_parts(chars, length as usize);
        String::from_utf16(char_vec).unwrap()
    }
}

/// Convert the given `jsid` to a `DOMString`. Fails if the `jsid` is not a
/// string, or if the string does not contain valid UTF-16.
pub fn jsid_to_str(cx: *mut JSContext, id: jsid) -> DOMString {
    unsafe {
        assert!(RUST_JSID_IS_STRING(id) != 0);
        jsstring_to_str(cx, RUST_JSID_TO_STRING(id))
    }
}

impl FromJSValConvertible for DOMString {
    type Config = StringificationBehavior;
    fn from_jsval(cx: *mut JSContext, value: JSVal,
                  null_behavior: StringificationBehavior)
                  -> Result<DOMString, ()> {
        if null_behavior == StringificationBehavior::Empty && value.is_null() {
            Ok("".to_owned())
        } else {
            let jsstr = unsafe { JS_ValueToString(cx, value) };
            if jsstr.is_null() {
                debug!("JS_ValueToString failed");
                Err(())
            } else {
                Ok(jsstring_to_str(cx, jsstr))
            }
        }
    }
}

impl ToJSValConvertible for USVString {
    fn to_jsval(&self, cx: *mut JSContext) -> JSVal {
        self.0.to_jsval(cx)
    }
}

impl FromJSValConvertible for USVString {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, value: JSVal, _: ())
                  -> Result<USVString, ()> {
        let jsstr = unsafe { JS_ValueToString(cx, value) };
        if jsstr.is_null() {
            debug!("JS_ValueToString failed");
            Err(())
        } else {
            unsafe {
                let mut length = 0;
                let chars = JS_GetStringCharsAndLength(cx, jsstr, &mut length);
                let char_vec = slice::from_raw_parts(chars, length as usize);
                Ok(USVString(String::from_utf16_lossy(char_vec)))
            }<commit_msg>Null-check the result of JS_GetStringCharsAndLength.<commit_after>/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

//! Conversions of Rust values to and from `JSVal`.
//!
//! | IDL type                | Argument type   | Return type    |
//! |-------------------------|-----------------|----------------|
//! | any                     | `JSVal`                          |
//! | boolean                 | `bool`                           |
//! | byte                    | `i8`                             |
//! | octet                   | `u8`                             |
//! | short                   | `i16`                            |
//! | unsigned short          | `u16`                            |
//! | long                    | `i32`                            |
//! | unsigned long           | `u32`                            |
//! | long long               | `i64`                            |
//! | unsigned long long      | `u64`                            |
//! | float                   | `f32`                            |
//! | double                  | `f64`                            |
//! | DOMString               | `DOMString`                      |
//! | USVString               | `USVString`                      |
//! | ByteString              | `ByteString`                     |
//! | object                  | `*mut JSObject`                  |
//! | interface types         | `JSRef<T>`      | `Temporary<T>` |
//! | dictionary types        | `&T`            | *unsupported*  |
//! | enumeration types       | `T`                              |
//! | callback function types | `T`                              |
//! | nullable types          | `Option<T>`                      |
//! | sequences               | `Vec<T>`                         |
//! | union types             | `T`                              |

use dom::bindings::codegen::PrototypeList;
use dom::bindings::js::{JSRef, Root, Unrooted};
use dom::bindings::str::{ByteString, USVString};
use dom::bindings::utils::{Reflectable, Reflector, DOMClass};
use util::str::DOMString;

use js;
use js::glue::{RUST_JSID_TO_STRING, RUST_JSID_IS_STRING};
use js::glue::RUST_JS_NumberValue;
use js::jsapi::{JSBool, JSContext, JSObject, JSString, jsid};
use js::jsapi::{JS_ValueToUint64, JS_ValueToInt64};
use js::jsapi::{JS_ValueToECMAUint32, JS_ValueToECMAInt32};
use js::jsapi::{JS_ValueToUint16, JS_ValueToNumber, JS_ValueToBoolean};
use js::jsapi::{JS_ValueToString, JS_GetStringCharsAndLength};
use js::jsapi::{JS_NewUCStringCopyN, JS_NewStringCopyN};
use js::jsapi::{JS_WrapValue};
use js::jsapi::{JSClass, JS_GetClass};
use js::jsval::JSVal;
use js::jsval::{UndefinedValue, NullValue, BooleanValue, Int32Value, UInt32Value};
use js::jsval::{StringValue, ObjectValue, ObjectOrNullValue};

use libc;
use std::borrow::ToOwned;
use std::default;
use std::slice;

/// A trait to retrieve the constants necessary to check if a `JSObject`
/// implements a given interface.
pub trait IDLInterface {
    /// Returns the prototype ID.
    fn get_prototype_id() -> PrototypeList::ID;
    /// Returns the prototype depth, i.e., the number of interfaces this
    /// interface inherits from.
    fn get_prototype_depth() -> usize;
}

/// A trait to convert Rust types to `JSVal`s.
pub trait ToJSValConvertible {
    /// Convert `self` to a `JSVal`. JSAPI failure causes a task failure.
    fn to_jsval(&self, cx: *mut JSContext) -> JSVal;
}

/// A trait to convert `JSVal`s to Rust types.
pub trait FromJSValConvertible {
    type Config;
    /// Convert `val` to type `Self`.
    /// Optional configuration of type `T` can be passed as the `option`
    /// argument.
    /// If it returns `Err(())`, a JSAPI exception is pending.
    fn from_jsval(cx: *mut JSContext, val: JSVal, option: Self::Config) -> Result<Self, ()>;
}


impl ToJSValConvertible for () {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        UndefinedValue()
    }
}

impl ToJSValConvertible for JSVal {
    fn to_jsval(&self, cx: *mut JSContext) -> JSVal {
        let mut value = *self;
        if unsafe { JS_WrapValue(cx, &mut value) } == 0 {
            panic!("JS_WrapValue failed.");
        }
        value
    }
}

unsafe fn convert_from_jsval<T: default::Default>(
    cx: *mut JSContext, value: JSVal,
    convert_fn: unsafe extern "C" fn(*mut JSContext, JSVal, *mut T) -> JSBool) -> Result<T, ()> {
    let mut ret = default::Default::default();
    if convert_fn(cx, value, &mut ret) == 0 {
        Err(())
    } else {
        Ok(ret)
    }
}


impl ToJSValConvertible for bool {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        BooleanValue(*self)
    }
}

impl FromJSValConvertible for bool {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<bool, ()> {
        let result = unsafe { convert_from_jsval(cx, val, JS_ValueToBoolean) };
        result.map(|b| b != 0)
    }
}

impl ToJSValConvertible for i8 {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        Int32Value(*self as i32)
    }
}

impl FromJSValConvertible for i8 {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<i8, ()> {
        let result = unsafe { convert_from_jsval(cx, val, JS_ValueToECMAInt32) };
        result.map(|v| v as i8)
    }
}

impl ToJSValConvertible for u8 {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        Int32Value(*self as i32)
    }
}

impl FromJSValConvertible for u8 {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<u8, ()> {
        let result = unsafe { convert_from_jsval(cx, val, JS_ValueToECMAInt32) };
        result.map(|v| v as u8)
    }
}

impl ToJSValConvertible for i16 {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        Int32Value(*self as i32)
    }
}

impl FromJSValConvertible for i16 {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<i16, ()> {
        let result = unsafe { convert_from_jsval(cx, val, JS_ValueToECMAInt32) };
        result.map(|v| v as i16)
    }
}

impl ToJSValConvertible for u16 {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        Int32Value(*self as i32)
    }
}

impl FromJSValConvertible for u16 {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<u16, ()> {
        unsafe { convert_from_jsval(cx, val, JS_ValueToUint16) }
    }
}

impl ToJSValConvertible for i32 {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        Int32Value(*self)
    }
}

impl FromJSValConvertible for i32 {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<i32, ()> {
        unsafe { convert_from_jsval(cx, val, JS_ValueToECMAInt32) }
    }
}

impl ToJSValConvertible for u32 {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        UInt32Value(*self)
    }
}

impl FromJSValConvertible for u32 {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<u32, ()> {
        unsafe { convert_from_jsval(cx, val, JS_ValueToECMAUint32) }
    }
}

impl ToJSValConvertible for i64 {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        unsafe {
            RUST_JS_NumberValue(*self as f64)
        }
    }
}

impl FromJSValConvertible for i64 {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<i64, ()> {
        unsafe { convert_from_jsval(cx, val, JS_ValueToInt64) }
    }
}

impl ToJSValConvertible for u64 {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        unsafe {
            RUST_JS_NumberValue(*self as f64)
        }
    }
}

impl FromJSValConvertible for u64 {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<u64, ()> {
        unsafe { convert_from_jsval(cx, val, JS_ValueToUint64) }
    }
}

impl ToJSValConvertible for f32 {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        unsafe {
            RUST_JS_NumberValue(*self as f64)
        }
    }
}

impl FromJSValConvertible for f32 {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<f32, ()> {
        let result = unsafe { convert_from_jsval(cx, val, JS_ValueToNumber) };
        result.map(|f| f as f32)
    }
}

impl ToJSValConvertible for f64 {
    fn to_jsval(&self, _cx: *mut JSContext) -> JSVal {
        unsafe {
            RUST_JS_NumberValue(*self)
        }
    }
}

impl FromJSValConvertible for f64 {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, val: JSVal, _option: ()) -> Result<f64, ()> {
        unsafe { convert_from_jsval(cx, val, JS_ValueToNumber) }
    }
}

impl ToJSValConvertible for str {
    fn to_jsval(&self, cx: *mut JSContext) -> JSVal {
        unsafe {
            let string_utf16: Vec<u16> = self.utf16_units().collect();
            let jsstr = JS_NewUCStringCopyN(cx, string_utf16.as_ptr(), string_utf16.len() as libc::size_t);
            if jsstr.is_null() {
                panic!("JS_NewUCStringCopyN failed");
            }
            StringValue(&*jsstr)
        }
    }
}

impl ToJSValConvertible for DOMString {
    fn to_jsval(&self, cx: *mut JSContext) -> JSVal {
        self.as_slice().to_jsval(cx)
    }
}

/// Behavior for stringification of `JSVal`s.
#[derive(PartialEq)]
pub enum StringificationBehavior {
    /// Convert `null` to the string `"null"`.
    Default,
    /// Convert `null` to the empty string.
    Empty,
}

impl default::Default for StringificationBehavior {
    fn default() -> StringificationBehavior {
        StringificationBehavior::Default
    }
}

/// Convert the given `JSString` to a `DOMString`. Fails if the string does not
/// contain valid UTF-16.
pub fn jsstring_to_str(cx: *mut JSContext, s: *mut JSString) -> DOMString {
    unsafe {
        let mut length = 0;
        let chars = JS_GetStringCharsAndLength(cx, s, &mut length);
        assert!(!chars.is_null());
        let char_vec = slice::from_raw_parts(chars, length as usize);
        String::from_utf16(char_vec).unwrap()
    }
}

/// Convert the given `jsid` to a `DOMString`. Fails if the `jsid` is not a
/// string, or if the string does not contain valid UTF-16.
pub fn jsid_to_str(cx: *mut JSContext, id: jsid) -> DOMString {
    unsafe {
        assert!(RUST_JSID_IS_STRING(id) != 0);
        jsstring_to_str(cx, RUST_JSID_TO_STRING(id))
    }
}

impl FromJSValConvertible for DOMString {
    type Config = StringificationBehavior;
    fn from_jsval(cx: *mut JSContext, value: JSVal,
                  null_behavior: StringificationBehavior)
                  -> Result<DOMString, ()> {
        if null_behavior == StringificationBehavior::Empty && value.is_null() {
            Ok("".to_owned())
        } else {
            let jsstr = unsafe { JS_ValueToString(cx, value) };
            if jsstr.is_null() {
                debug!("JS_ValueToString failed");
                Err(())
            } else {
                Ok(jsstring_to_str(cx, jsstr))
            }
        }
    }
}

impl ToJSValConvertible for USVString {
    fn to_jsval(&self, cx: *mut JSContext) -> JSVal {
        self.0.to_jsval(cx)
    }
}

impl FromJSValConvertible for USVString {
    type Config = ();
    fn from_jsval(cx: *mut JSContext, value: JSVal, _: ())
                  -> Result<USVString, ()> {
        let jsstr = unsafe { JS_ValueToString(cx, value) };
        if jsstr.is_null() {
            debug!("JS_ValueToString failed");
            Err(())
        } else {
            unsafe {
                let mut length = 0;
                let chars = JS_GetStringCharsAndLength(cx, jsstr, &mut length);
                assert!(!chars.is_null());
                let char_vec = slice::from_raw_parts(chars, length as usize);
                Ok(USVString(String::from_utf16_lossy(char_vec)))
            }
{'fraction_non_alphanumeric': 0.1347798873356979, 'fraction_numerical': 0.013603171291466723, 'mean_word_length': 2.121792366809952, 'pattern_counts': {'":': 0, '<': 45, '<?xml version=': 0, '>': 121, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 10, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
{'dir': 'git-commits-cleaned', 'id': '6806324', 'n_tokens_mistral': 7998, 'n_tokens_neox': 7737, 'n_words': 1938}