Specification compliant `ToBigInt` (`to_bigint`) (#450)

- Merged Ast `BigInt` to Builtin `BigInt`.
 - Split `BigInt` logic to separate files.
 - Added `builtins/bigint/operations.rs` for `BigInt` operations.
 - Added `builtins/bigint/conversions.rs` for `BigInt` conversions.
 - Added` builtins/bigint/equality.rs` for `BigInt` equality checking.
 - Added tests.

boa/src/builtins/bigint/conversions.rs

@@ -0,0 +1,96 @@
+use super::BigInt;
+
+use crate::{
+    builtins::{Number, Value},
+    exec::Interpreter,
+};
+use num_traits::cast::{FromPrimitive, ToPrimitive};
+
+use std::convert::TryFrom;
+use std::str::FromStr;
+
+impl BigInt {
+    /// This function takes a string and conversts it to BigInt type.
+    ///
+    /// More information:
+    ///  - [ECMAScript reference][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-stringtobigint
+    #[inline]
+    pub(crate) fn from_string(string: &str, _ctx: &mut Interpreter) -> Result<Self, Value> {
+        if string.is_empty() {
+            return Ok(BigInt::from(0));
+        }
+
+        match num_bigint::BigInt::from_str(string) {
+            Ok(bigint) => Ok(Self(bigint)),
+            _ => panic!("SyntaxError: cannot convert {} to a BigInt", string),
+        }
+    }
+
+    /// Converts a string to a BigInt with the specified radix.
+    #[inline]
+    pub fn from_string_radix(buf: &str, radix: u32) -> Option<Self> {
+        num_bigint::BigInt::parse_bytes(buf.as_bytes(), radix).map(Self)
+    }
+
+    /// Convert bigint to string with radix.
+    #[inline]
+    pub fn to_string_radix(&self, radix: u32) -> String {
+        self.0.to_str_radix(radix)
+    }
+
+    /// Converts the BigInt to a f64 type.
+    ///
+    /// Returns `std::f64::INFINITY` if the BigInt is too big.
+    #[inline]
+    pub fn to_f64(&self) -> f64 {
+        self.0.to_f64().unwrap_or(std::f64::INFINITY)
+    }
+
+    #[inline]
+    pub(crate) fn from_str(string: &str) -> Option<Self> {
+        match num_bigint::BigInt::from_str(string) {
+            Ok(bigint) => Some(BigInt(bigint)),
+            Err(_) => None,
+        }
+    }
+}
+
+impl From<i64> for BigInt {
+    fn from(n: i64) -> BigInt {
+        BigInt(num_bigint::BigInt::from(n))
+    }
+}
+
+impl From<i32> for BigInt {
+    fn from(n: i32) -> BigInt {
+        BigInt(num_bigint::BigInt::from(n))
+    }
+}
+
+#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, PartialOrd, Ord)]
+pub struct TryFromF64Error;
+
+impl std::fmt::Display for TryFromF64Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "Could not convert f64 value to a BigInt type")
+    }
+}
+
+impl TryFrom<f64> for BigInt {
+    type Error = TryFromF64Error;
+
+    fn try_from(n: f64) -> Result<Self, Self::Error> {
+        // If the truncated version of the number is not the
+        // same as the non-truncated version then the floating-point
+        // number conains a fractional part.
+        if !Number::equal(n.trunc(), n) {
+            return Err(TryFromF64Error);
+        }
+        match num_bigint::BigInt::from_f64(n) {
+            Some(bigint) => Ok(BigInt(bigint)),
+            None => Err(TryFromF64Error),
+        }
+    }
+}

boa/src/builtins/bigint/equality.rs

@@ -0,0 +1,74 @@
+use super::BigInt;
+
+impl BigInt {
+    /// Checks for `SameValueZero` equality.
+    ///
+    /// More information:
+    ///  - [ECMAScript reference][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-numeric-types-bigint-equal
+    #[inline]
+    pub(crate) fn same_value_zero(x: &Self, y: &Self) -> bool {
+        // Return BigInt::equal(x, y)
+        Self::equal(x, y)
+    }
+
+    /// Checks for `SameValue` equality.
+    ///
+    ///
+    /// More information:
+    ///  - [ECMAScript reference][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-numeric-types-bigint-sameValue
+    #[inline]
+    pub(crate) fn same_value(x: &Self, y: &Self) -> bool {
+        // Return BigInt::equal(x, y)
+        Self::equal(x, y)
+    }
+
+    /// Checks for mathematical equality.
+    ///
+    /// The abstract operation BigInt::equal takes arguments x (a `BigInt`) and y (a `BigInt`).
+    /// It returns `true` if x and y have the same mathematical integer value and false otherwise.
+    ///
+    /// More information:
+    ///  - [ECMAScript reference][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-numeric-types-bigint-sameValueZero
+    #[inline]
+    pub(crate) fn equal(x: &Self, y: &Self) -> bool {
+        x == y
+    }
+}
+
+impl PartialEq<i32> for BigInt {
+    fn eq(&self, other: &i32) -> bool {
+        self.0 == num_bigint::BigInt::from(*other)
+    }
+}
+
+impl PartialEq<BigInt> for i32 {
+    fn eq(&self, other: &BigInt) -> bool {
+        num_bigint::BigInt::from(*self) == other.0
+    }
+}
+
+impl PartialEq<f64> for BigInt {
+    fn eq(&self, other: &f64) -> bool {
+        if other.fract() != 0.0 {
+            return false;
+        }
+
+        self.0 == num_bigint::BigInt::from(*other as i64)
+    }
+}
+
+impl PartialEq<BigInt> for f64 {
+    fn eq(&self, other: &BigInt) -> bool {
+        if self.fract() != 0.0 {
+            return false;
+        }
+
+        num_bigint::BigInt::from(*self as i64) == other.0
+    }
+}

boa/src/builtins/bigint/mod.rs

@@ -15,21 +15,67 @@
 use crate::{
     builtins::{
         function::{make_builtin_fn, make_constructor_fn},
-        value::{ResultValue, Value},
+        value::{ResultValue, Value, ValueData},
     },
     exec::Interpreter,
-    syntax::ast::bigint::BigInt as AstBigInt,
     BoaProfiler,
 };
 
+use gc::{unsafe_empty_trace, Finalize, Trace};
+
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
+pub mod conversions;
+pub mod equality;
+pub mod operations;
+
+pub use conversions::*;
+pub use equality::*;
+pub use operations::*;
+
 #[cfg(test)]
 mod tests;
 
 /// `BigInt` implementation.
-#[derive(Debug, Clone, Copy)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-pub(crate) struct BigInt;
+#[derive(Clone, Hash, PartialEq, Eq, PartialOrd, Ord, Default)]
+pub struct BigInt(num_bigint::BigInt);
 
 impl BigInt {
+    /// The abstract operation thisBigIntValue takes argument value.
+    ///
+    /// The phrase “this BigInt value” within the specification of a method refers to the
+    /// result returned by calling the abstract operation thisBigIntValue with the `this` value
+    /// of the method invocation passed as the argument.
+    ///
+    /// More information:
+    ///  - [ECMAScript reference][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-thisbigintvalue
+    #[inline]
+    fn this_bigint_value(value: &Value, ctx: &mut Interpreter) -> Result<Self, Value> {
+        match value.data() {
+            // 1. If Type(value) is BigInt, return value.
+            ValueData::BigInt(ref bigint) => return Ok(bigint.clone()),
+
+            // 2. If Type(value) is Object and value has a [[BigIntData]] internal slot, then
+            //    a. Assert: Type(value.[[BigIntData]]) is BigInt.
+            //    b. Return value.[[BigIntData]].
+            ValueData::Object(_) => {
+                let bigint = value.get_internal_slot("BigIntData");
+                if let ValueData::BigInt(bigint) = bigint.data() {
+                    return Ok(bigint.clone());
+                }
+            }
+            _ => {}
+        }
+
+        // 3. Throw a TypeError exception.
+        ctx.throw_type_error("'this' is not a BigInt")?;
+        unreachable!();
+    }
+
     /// `BigInt()`
     ///
     /// The `BigInt()` constructor is used to create BigInt objects.
@@ -46,34 +92,12 @@ impl BigInt {
         ctx: &mut Interpreter,
     ) -> ResultValue {
         let data = match args.get(0) {
-            Some(ref value) => {
+            Some(ref value) => Value::from(ctx.to_bigint(value)?),
-                if let Some(bigint) = value.to_bigint() {
+            None => Value::from(Self::from(0)),
-                    Value::from(bigint)
-                } else {
-                    let message = format!(
-                        "{} can't be converted to BigInt because it isn't an integer",
-                        ctx.to_string(value)?
-                    );
-                    return ctx.throw_range_error(message);
-                }
-            }
-            None => Value::from(AstBigInt::from(0)),
         };
         Ok(data)
     }
 
-    #[inline]
-    #[allow(clippy::wrong_self_convention)]
-    pub(crate) fn to_native_string_radix(bigint: &AstBigInt, radix: u32) -> String {
-        bigint.to_str_radix(radix)
-    }
-
-    #[inline]
-    #[allow(clippy::wrong_self_convention)]
-    pub(crate) fn to_native_string(bigint: &AstBigInt) -> String {
-        bigint.to_string()
-    }
-
     /// `BigInt.prototype.toString( [radix] )`
     ///
     /// The `toString()` method returns a string representing the specified BigInt object.
@@ -99,10 +123,9 @@ impl BigInt {
             return ctx
                 .throw_range_error("radix must be an integer at least 2 and no greater than 36");
         }
-        Ok(Value::from(Self::to_native_string_radix(
+        Ok(Value::from(
-            &this.to_bigint().unwrap(),
+            Self::this_bigint_value(this, ctx)?.to_string_radix(radix as u32),
-            radix as u32,
+        ))
-        )))
     }
 
     /// `BigInt.prototype.valueOf()`
@@ -118,17 +141,15 @@ impl BigInt {
     pub(crate) fn value_of(
         this: &mut Value,
         _args: &[Value],
-        _ctx: &mut Interpreter,
+        ctx: &mut Interpreter,
     ) -> ResultValue {
-        Ok(Value::from(
+        Ok(Value::from(Self::this_bigint_value(this, ctx)?))
-            this.to_bigint().expect("BigInt.prototype.valueOf"),
-        ))
     }
 
     /// Create a new `Number` object
     pub(crate) fn create(global: &Value) -> Value {
         let prototype = Value::new_object(Some(global));
-        prototype.set_internal_slot("BigIntData", Value::from(AstBigInt::from(0)));
+        prototype.set_internal_slot("BigIntData", Value::from(Self::from(0)));
 
         make_builtin_fn(Self::to_string, "toString", &prototype, 1);
         make_builtin_fn(Self::value_of, "valueOf", &prototype, 0);
@@ -143,3 +164,11 @@ impl BigInt {
         global.set_field("BigInt", Self::create(global));
     }
 }
+
+impl Finalize for BigInt {}
+unsafe impl Trace for BigInt {
+    // BigInt type implements an empty trace becasue the inner structure
+    // `num_bigint::BigInt` does not implement `Trace` trait.
+    // If it did this would be unsound.
+    unsafe_empty_trace!();
+}

boa/src/builtins/bigint/operations.rs

@@ -0,0 +1,104 @@
+//! This module implements the `BigInt` operations.
+
+use num_traits::cast::ToPrimitive;
+use num_traits::pow::Pow;
+
+use super::BigInt;
+
+impl BigInt {
+    #[inline]
+    pub fn pow(self, other: &Self) -> Self {
+        Self(
+            self.0.pow(
+                other
+                    .0
+                    .to_biguint()
+                    .expect("RangeError: \"BigInt negative exponent\""),
+            ),
+        )
+    }
+}
+
+macro_rules! impl_bigint_operator {
+    ($op:ident, $op_method:ident, $assign_op:ident, $assign_op_method:ident) => {
+        impl std::ops::$op for BigInt {
+            type Output = Self;
+
+            fn $op_method(mut self, other: Self) -> Self {
+                std::ops::$assign_op::$assign_op_method(&mut self.0, other.0);
+                self
+            }
+        }
+    };
+}
+
+impl_bigint_operator!(Add, add, AddAssign, add_assign);
+impl_bigint_operator!(Sub, sub, SubAssign, sub_assign);
+impl_bigint_operator!(Mul, mul, MulAssign, mul_assign);
+impl_bigint_operator!(Div, div, DivAssign, div_assign);
+impl_bigint_operator!(Rem, rem, RemAssign, rem_assign);
+impl_bigint_operator!(BitAnd, bitand, BitAndAssign, bitand_assign);
+impl_bigint_operator!(BitOr, bitor, BitOrAssign, bitor_assign);
+impl_bigint_operator!(BitXor, bitxor, BitXorAssign, bitxor_assign);
+
+impl std::ops::Shr for BigInt {
+    type Output = Self;
+
+    fn shr(mut self, other: Self) -> Self::Output {
+        use std::ops::ShlAssign;
+        use std::ops::ShrAssign;
+
+        if let Some(n) = other.0.to_i32() {
+            if n > 0 {
+                self.0.shr_assign(n as usize)
+            } else {
+                self.0.shl_assign(n.abs() as usize)
+            }
+
+            return self;
+        }
+
+        panic!("RangeError: Maximum BigInt size exceeded");
+    }
+}
+
+impl std::ops::Shl for BigInt {
+    type Output = Self;
+
+    fn shl(mut self, other: Self) -> Self::Output {
+        use std::ops::ShlAssign;
+        use std::ops::ShrAssign;
+
+        if let Some(n) = other.0.to_i32() {
+            if n > 0 {
+                self.0.shl_assign(n as usize)
+            } else {
+                self.0.shr_assign(n.abs() as usize)
+            }
+
+            return self;
+        }
+
+        panic!("RangeError: Maximum BigInt size exceeded");
+    }
+}
+
+impl std::ops::Neg for BigInt {
+    type Output = Self;
+
+    fn neg(self) -> Self::Output {
+        Self(-self.0)
+    }
+}
+
+impl std::fmt::Debug for BigInt {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
+
+impl std::fmt::Display for BigInt {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}

boa/src/builtins/bigint/tests.rs

@@ -1,4 +1,4 @@
-use crate::{forward, Interpreter, Realm};
+use crate::{forward, forward_val, Interpreter, Realm};
 
 #[test]
 fn equality() {
@@ -55,7 +55,7 @@ fn equality() {
 }
 
 #[test]
-fn bigint_function_conversion() {
+fn bigint_function_conversion_from_integer() {
     let realm = Realm::create();
     let mut engine = Interpreter::new(realm);
 
@@ -70,6 +70,83 @@ fn bigint_function_conversion() {
     );
 }
 
+#[test]
+fn bigint_function_conversion_from_rational() {
+    let realm = Realm::create();
+    let mut engine = Interpreter::new(realm);
+
+    assert_eq!(forward(&mut engine, "BigInt(0.0)"), "0n");
+    assert_eq!(forward(&mut engine, "BigInt(1.0)"), "1n");
+    assert_eq!(forward(&mut engine, "BigInt(10000.0)"), "10000n");
+}
+
+#[test]
+fn bigint_function_conversion_from_rational_with_fractional_part() {
+    let realm = Realm::create();
+    let mut engine = Interpreter::new(realm);
+
+    let scenario = r#"
+        var x = false;
+        try {
+            BigInt(0.1);
+        } catch (e) {
+            x = true;
+        }
+    "#;
+    forward_val(&mut engine, scenario).unwrap();
+    assert_eq!(forward(&mut engine, "x"), "true");
+}
+
+#[test]
+fn bigint_function_conversion_from_null() {
+    let realm = Realm::create();
+    let mut engine = Interpreter::new(realm);
+
+    let scenario = r#"
+        var x = false;
+        try {
+            BigInt(null);
+        } catch (e) {
+            x = true;
+        }
+    "#;
+    forward_val(&mut engine, scenario).unwrap();
+    assert_eq!(forward(&mut engine, "x"), "true");
+}
+
+#[test]
+fn bigint_function_conversion_from_undefined() {
+    let realm = Realm::create();
+    let mut engine = Interpreter::new(realm);
+
+    let scenario = r#"
+        var x = false;
+        try {
+            BigInt(undefined);
+        } catch (e) {
+            x = true;
+        }
+    "#;
+    forward_val(&mut engine, scenario).unwrap();
+    assert_eq!(forward(&mut engine, "x"), "true");
+}
+
+#[test]
+fn bigint_function_conversion_from_string() {
+    let realm = Realm::create();
+    let mut engine = Interpreter::new(realm);
+
+    assert_eq!(forward(&mut engine, "BigInt('')"), "0n");
+    assert_eq!(
+        forward(&mut engine, "BigInt('200000000000000000')"),
+        "200000000000000000n"
+    );
+    assert_eq!(
+        forward(&mut engine, "BigInt('1000000000000000000000000000000000')"),
+        "1000000000000000000000000000000000n"
+    );
+}
+
 #[test]
 fn add() {
     let realm = Realm::create();
@@ -138,10 +215,7 @@ fn to_string() {
     let mut engine = Interpreter::new(realm);
 
     assert_eq!(forward(&mut engine, "1000n.toString()"), "1000");
-
     assert_eq!(forward(&mut engine, "1000n.toString(2)"), "1111101000");
-
     assert_eq!(forward(&mut engine, "255n.toString(16)"), "ff");
-
     assert_eq!(forward(&mut engine, "1000n.toString(36)"), "rs");
 }

boa/src/builtins/mod.rs

@@ -21,6 +21,7 @@ pub(crate) use self::{
     bigint::BigInt,
     boolean::Boolean,
     error::{Error, RangeError, TypeError},
+    function::Function,
     number::Number,
     regexp::RegExp,
     string::String,

boa/src/builtins/number/mod.rs

@@ -445,8 +445,8 @@ impl Number {
     ///
     /// https://tc39.es/ecma262/#sec-numeric-types-number-equal
     #[allow(clippy::float_cmp)]
-    pub(crate) fn equals(a: f64, b: f64) -> bool {
+    pub(crate) fn equal(x: f64, y: f64) -> bool {
-        a == b
+        x == y
     }
 
     /// The abstract operation Number::sameValue takes arguments
@@ -476,11 +476,11 @@ impl Number {
     ///
     /// https://tc39.es/ecma262/#sec-numeric-types-number-sameValueZero
     #[allow(clippy::float_cmp)]
-    pub(crate) fn same_value_zero(a: f64, b: f64) -> bool {
+    pub(crate) fn same_value_zero(x: f64, y: f64) -> bool {
-        if a.is_nan() && b.is_nan() {
+        if x.is_nan() && y.is_nan() {
             return true;
         }
 
-        a == b
+        x == y
     }
 }

boa/src/builtins/number/tests.rs

@@ -403,13 +403,13 @@ fn value_of() {
 
 #[test]
 fn equal() {
-    assert_eq!(Number::equals(0.0, 0.0), true);
+    assert_eq!(Number::equal(0.0, 0.0), true);
-    assert_eq!(Number::equals(-0.0, 0.0), true);
+    assert_eq!(Number::equal(-0.0, 0.0), true);
-    assert_eq!(Number::equals(0.0, -0.0), true);
+    assert_eq!(Number::equal(0.0, -0.0), true);
-    assert_eq!(Number::equals(f64::NAN, -0.0), false);
+    assert_eq!(Number::equal(f64::NAN, -0.0), false);
-    assert_eq!(Number::equals(0.0, f64::NAN), false);
+    assert_eq!(Number::equal(0.0, f64::NAN), false);
 
-    assert_eq!(Number::equals(1.0, 1.0), true);
+    assert_eq!(Number::equal(1.0, 1.0), true);
 }
 
 #[test]
@@ -419,7 +419,7 @@ fn same_value() {
     assert_eq!(Number::same_value(0.0, -0.0), false);
     assert_eq!(Number::same_value(f64::NAN, -0.0), false);
     assert_eq!(Number::same_value(0.0, f64::NAN), false);
-    assert_eq!(Number::equals(1.0, 1.0), true);
+    assert_eq!(Number::equal(1.0, 1.0), true);
 }
 
 #[test]
@@ -429,7 +429,7 @@ fn same_value_zero() {
     assert_eq!(Number::same_value_zero(0.0, -0.0), true);
     assert_eq!(Number::same_value_zero(f64::NAN, -0.0), false);
     assert_eq!(Number::same_value_zero(0.0, f64::NAN), false);
-    assert_eq!(Number::equals(1.0, 1.0), true);
+    assert_eq!(Number::equal(1.0, 1.0), true);
 }
 
 #[test]

boa/src/builtins/value/conversions.rs

@@ -83,26 +83,6 @@ impl From<&Value> for i32 {
     }
 }
 
-#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
-pub struct TryFromBigIntError;
-
-impl Display for TryFromBigIntError {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "Could not convert value to a BigInt type")
-    }
-}
-
-impl TryFrom<&Value> for BigInt {
-    type Error = TryFromBigIntError;
-
-    fn try_from(value: &Value) -> Result<Self, Self::Error> {
-        match value.data() {
-            ValueData::BigInt(ref bigint) => Ok(bigint.clone()),
-            _ => Err(TryFromBigIntError),
-        }
-    }
-}
-
 impl From<BigInt> for Value {
     fn from(value: BigInt) -> Self {
         Value::bigint(value)

boa/src/builtins/value/equality.rs

@@ -0,0 +1,215 @@
+use super::*;
+use crate::{builtins::Number, Interpreter};
+
+use std::borrow::Borrow;
+
+impl Value {
+    /// Strict equality comparison.
+    ///
+    /// This method is executed when doing strict equality comparisons with the `===` operator.
+    /// For more information, check <https://tc39.es/ecma262/#sec-strict-equality-comparison>.
+    pub fn strict_equals(&self, other: &Self) -> bool {
+        // 1. If Type(x) is different from Type(y), return false.
+        if self.get_type() != other.get_type() {
+            return false;
+        }
+
+        match (self.data(), other.data()) {
+            // 2. If Type(x) is Number or BigInt, then
+            //    a. Return ! Type(x)::equal(x, y).
+            (ValueData::BigInt(x), ValueData::BigInt(y)) => BigInt::equal(x, y),
+            (ValueData::Rational(x), ValueData::Rational(y)) => Number::equal(*x, *y),
+            (ValueData::Rational(x), ValueData::Integer(y)) => Number::equal(*x, f64::from(*y)),
+            (ValueData::Integer(x), ValueData::Rational(y)) => Number::equal(f64::from(*x), *y),
+            (ValueData::Integer(x), ValueData::Integer(y)) => x == y,
+
+            //Null has to be handled specially because "typeof null" returns object and if we managed
+            //this without a special case we would compare self and other as if they were actually
+            //objects which unfortunately fails
+            //Specification Link: https://tc39.es/ecma262/#sec-typeof-operator
+            (ValueData::Null, ValueData::Null) => true,
+
+            // 3. Return ! SameValueNonNumeric(x, y).
+            (_, _) => same_value_non_numeric(self, other),
+        }
+    }
+
+    /// Abstract equality comparison.
+    ///
+    /// This method is executed when doing abstract equality comparisons with the `==` operator.
+    ///  For more information, check <https://tc39.es/ecma262/#sec-abstract-equality-comparison>
+    #[allow(clippy::float_cmp)]
+    pub fn equals(&mut self, other: &mut Self, interpreter: &mut Interpreter) -> bool {
+        // 1. If Type(x) is the same as Type(y), then
+        //     a. Return the result of performing Strict Equality Comparison x === y.
+        if self.get_type() == other.get_type() {
+            return self.strict_equals(other);
+        }
+
+        match (self.data(), other.data()) {
+            // 2. If x is null and y is undefined, return true.
+            // 3. If x is undefined and y is null, return true.
+            _ if self.is_null_or_undefined() && other.is_null_or_undefined() => true,
+
+            // 3. If Type(x) is Number and Type(y) is String, return the result of the comparison x == ! ToNumber(y).
+            // 4. If Type(x) is String and Type(y) is Number, return the result of the comparison ! ToNumber(x) == y.
+            //
+            // https://github.com/rust-lang/rust/issues/54883
+            (ValueData::Integer(_), ValueData::String(_))
+            | (ValueData::Rational(_), ValueData::String(_))
+            | (ValueData::String(_), ValueData::Integer(_))
+            | (ValueData::String(_), ValueData::Rational(_))
+            | (ValueData::Rational(_), ValueData::Boolean(_))
+            | (ValueData::Integer(_), ValueData::Boolean(_)) => {
+                let a: &Value = self.borrow();
+                let b: &Value = other.borrow();
+                Number::equal(f64::from(a), f64::from(b))
+            }
+
+            // 6. If Type(x) is BigInt and Type(y) is String, then
+            //    a. Let n be ! StringToBigInt(y).
+            //    b. If n is NaN, return false.
+            //    c. Return the result of the comparison x == n.
+            (ValueData::BigInt(ref a), ValueData::String(ref b)) => match string_to_bigint(b) {
+                Some(ref b) => a == b,
+                None => false,
+            },
+
+            // 7. If Type(x) is String and Type(y) is BigInt, return the result of the comparison y == x.
+            (ValueData::String(ref a), ValueData::BigInt(ref b)) => match string_to_bigint(a) {
+                Some(ref a) => a == b,
+                None => false,
+            },
+
+            // 8. If Type(x) is Boolean, return the result of the comparison ! ToNumber(x) == y.
+            (ValueData::Boolean(_), _) => {
+                other.equals(&mut Value::from(self.to_integer()), interpreter)
+            }
+
+            // 9. If Type(y) is Boolean, return the result of the comparison x == ! ToNumber(y).
+            (_, ValueData::Boolean(_)) => {
+                self.equals(&mut Value::from(other.to_integer()), interpreter)
+            }
+
+            // 10. If Type(x) is either String, Number, BigInt, or Symbol and Type(y) is Object, return the result
+            // of the comparison x == ? ToPrimitive(y).
+            (ValueData::Object(_), _) => {
+                let mut primitive = interpreter.to_primitive(self, None);
+                primitive.equals(other, interpreter)
+            }
+
+            // 11. If Type(x) is Object and Type(y) is either String, Number, BigInt, or Symbol, return the result
+            // of the comparison ? ToPrimitive(x) == y.
+            (_, ValueData::Object(_)) => {
+                let mut primitive = interpreter.to_primitive(other, None);
+                primitive.equals(self, interpreter)
+            }
+
+            // 12. If Type(x) is BigInt and Type(y) is Number, or if Type(x) is Number and Type(y) is BigInt, then
+            //    a. If x or y are any of NaN, +∞, or -∞, return false.
+            //    b. If the mathematical value of x is equal to the mathematical value of y, return true; otherwise return false.
+            (ValueData::BigInt(ref a), ValueData::Rational(ref b)) => a == b,
+            (ValueData::Rational(ref a), ValueData::BigInt(ref b)) => a == b,
+            (ValueData::BigInt(ref a), ValueData::Integer(ref b)) => a == b,
+            (ValueData::Integer(ref a), ValueData::BigInt(ref b)) => a == b,
+
+            // 13. Return false.
+            _ => false,
+        }
+    }
+}
+
+/// This function takes a string and conversts it to BigInt type.
+///
+/// If the result is `NaN` than `None` is returned.
+///
+/// More information:
+///  - [ECMAScript reference][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#sec-stringtobigint
+pub fn string_to_bigint(string: &str) -> Option<BigInt> {
+    if string.is_empty() {
+        return Some(BigInt::from(0));
+    }
+
+    BigInt::from_str(string)
+}
+
+/// The internal comparison abstract operation SameValue(x, y),
+/// where x and y are ECMAScript language values, produces true or false.
+/// Such a comparison is performed as follows:
+///
+/// https://tc39.es/ecma262/#sec-samevalue
+/// strict mode currently compares the pointers
+pub fn same_value(x: &Value, y: &Value, strict: bool) -> bool {
+    if strict {
+        // Do both Values point to the same underlying valueData?
+        return std::ptr::eq(x.data(), y.data());
+    }
+
+    // 1. If Type(x) is different from Type(y), return false.
+    if x.get_type() != y.get_type() {
+        return false;
+    }
+
+    match (x.data(), y.data()) {
+        // 2. If Type(x) is Number or BigInt, then
+        //    a. Return ! Type(x)::SameValue(x, y).
+        (ValueData::BigInt(x), ValueData::BigInt(y)) => BigInt::same_value(x, y),
+        (ValueData::Rational(x), ValueData::Rational(y)) => Number::same_value(*x, *y),
+        (ValueData::Rational(x), ValueData::Integer(y)) => Number::same_value(*x, f64::from(*y)),
+        (ValueData::Integer(x), ValueData::Rational(y)) => Number::same_value(f64::from(*x), *y),
+        (ValueData::Integer(x), ValueData::Integer(y)) => x == y,
+
+        // 3. Return ! SameValueNonNumeric(x, y).
+        (_, _) => same_value_non_numeric(x, y),
+    }
+}
+
+/// The internal comparison abstract operation SameValueZero(x, y),
+/// where x and y are ECMAScript language values, produces true or false.
+/// SameValueZero differs from SameValue only in its treatment of +0 and -0.
+///
+/// Such a comparison is performed as follows:
+///
+/// <https://tc39.es/ecma262/#sec-samevaluezero>
+pub fn same_value_zero(x: &Value, y: &Value) -> bool {
+    if x.get_type() != y.get_type() {
+        return false;
+    }
+
+    match (x.data(), y.data()) {
+        // 2. If Type(x) is Number or BigInt, then
+        //    a. Return ! Type(x)::SameValueZero(x, y).
+        (ValueData::BigInt(x), ValueData::BigInt(y)) => BigInt::same_value_zero(x, y),
+
+        (ValueData::Rational(x), ValueData::Rational(y)) => Number::same_value_zero(*x, *y),
+        (ValueData::Rational(x), ValueData::Integer(y)) => {
+            Number::same_value_zero(*x, f64::from(*y))
+        }
+        (ValueData::Integer(x), ValueData::Rational(y)) => {
+            Number::same_value_zero(f64::from(*x), *y)
+        }
+        (ValueData::Integer(x), ValueData::Integer(y)) => x == y,
+
+        // 3. Return ! SameValueNonNumeric(x, y).
+        (_, _) => same_value_non_numeric(x, y),
+    }
+}
+
+pub fn same_value_non_numeric(x: &Value, y: &Value) -> bool {
+    debug_assert!(x.get_type() == y.get_type());
+    match x.get_type() {
+        "undefined" => true,
+        "null" => true,
+        "string" => {
+            if x.to_string() == y.to_string() {
+                return true;
+            }
+            false
+        }
+        "boolean" => bool::from(x) == bool::from(y),
+        "object" => std::ptr::eq(x, y),
+        _ => false,
+    }
+}

boa/src/builtins/value/mod.rs

@@ -6,20 +6,20 @@
 mod tests;
 
 use crate::builtins::{
-    function::Function,
     object::{
         internal_methods_trait::ObjectInternalMethods, InternalState, InternalStateCell, Object,
         ObjectKind, INSTANCE_PROTOTYPE, PROTOTYPE,
     },
     property::Property,
+    BigInt, Function,
 };
-use crate::{syntax::ast::bigint::BigInt, BoaProfiler};
+use crate::BoaProfiler;
+
 use gc::{Finalize, Gc, GcCell, GcCellRef, Trace};
 use serde_json::{map::Map, Number as JSONNumber, Value as JSONValue};
 use std::{
     any::Any,
     collections::HashSet,
-    convert::TryFrom,
     f64::NAN,
     fmt::{self, Display},
     ops::{Add, BitAnd, BitOr, BitXor, Deref, DerefMut, Div, Mul, Neg, Not, Rem, Shl, Shr, Sub},
@@ -28,9 +28,12 @@ use std::{
 
 pub mod conversions;
 pub mod display;
+pub mod equality;
 pub mod operations;
+
 pub use conversions::*;
 pub(crate) use display::display_obj;
+pub use equality::*;
 pub use operations::*;
 
 /// The result of a Javascript expression is represented like this so it can succeed (`Ok`) or fail (`Err`)
@@ -220,7 +223,7 @@ impl ValueData {
         }
     }
 
-    /// Returns true if the value is undefined
+    /// Returns true if the value is undefined.
     pub fn is_undefined(&self) -> bool {
         match *self {
             Self::Undefined => true,
@@ -228,7 +231,7 @@ impl ValueData {
         }
     }
 
-    /// Returns true if the value is null
+    /// Returns true if the value is null.
     pub fn is_null(&self) -> bool {
         match *self {
             Self::Null => true,
@@ -236,7 +239,7 @@ impl ValueData {
         }
     }
 
-    /// Returns true if the value is null or undefined
+    /// Returns true if the value is null or undefined.
     pub fn is_null_or_undefined(&self) -> bool {
         match *self {
             Self::Null | Self::Undefined => true,
@@ -244,7 +247,7 @@ impl ValueData {
         }
     }
 
-    /// Returns true if the value is a 64-bit floating-point number
+    /// Returns true if the value is a 64-bit floating-point number.
     pub fn is_double(&self) -> bool {
         match *self {
             Self::Rational(_) => true,
@@ -290,6 +293,14 @@ impl ValueData {
         }
     }
 
+    /// Returns true if the value is a bigint
+    pub fn is_bigint(&self) -> bool {
+        match *self {
+            Self::BigInt(_) => true,
+            _ => false,
+        }
+    }
+
     /// Returns true if the value is true
     ///
     /// [toBoolean](https://tc39.es/ecma262/#sec-toboolean)
@@ -350,27 +361,6 @@ impl ValueData {
         }
     }
 
-    /// Helper function.
-    pub fn to_bigint(&self) -> Option<BigInt> {
-        match self {
-            Self::String(ref string) => string_to_bigint(string),
-            Self::Boolean(true) => Some(BigInt::from(1)),
-            Self::Boolean(false) | Self::Null => Some(BigInt::from(0)),
-            Self::Rational(num) => BigInt::try_from(*num).ok(),
-            Self::Integer(num) => Some(BigInt::from(*num)),
-            ValueData::BigInt(b) => Some(b.clone()),
-            ValueData::Object(ref o) => {
-                let object = (o).deref().borrow();
-                if object.kind == ObjectKind::BigInt {
-                    object.get_internal_slot("BigIntData").to_bigint()
-                } else {
-                    None
-                }
-            }
-            _ => None,
-        }
-    }
-
     pub fn as_object(&self) -> Option<GcCellRef<'_, Object>> {
         match *self {
             ValueData::Object(ref o) => Some(o.borrow()),

boa/src/builtins/value/operations.rs

@@ -1,177 +1,4 @@
 use super::*;
-use crate::{builtins::Number, Interpreter};
-
-use std::borrow::Borrow;
-use std::convert::TryFrom;
-
-impl Value {
-    /// Strict equality comparison.
-    ///
-    /// This method is executed when doing strict equality comparisons with the `===` operator.
-    /// For more information, check <https://tc39.es/ecma262/#sec-strict-equality-comparison>.
-    pub fn strict_equals(&self, other: &Self) -> bool {
-        if self.get_type() != other.get_type() {
-            return false;
-        }
-
-        if self.is_number() {
-            return Number::equals(f64::from(self), f64::from(other));
-        }
-
-        //Null has to be handled specially because "typeof null" returns object and if we managed
-        //this without a special case we would compare self and other as if they were actually
-        //objects which unfortunately fails
-        //Specification Link: https://tc39.es/ecma262/#sec-typeof-operator
-        if self.is_null() {
-            return true;
-        }
-
-        same_value_non_number(self, other)
-    }
-
-    /// Abstract equality comparison.
-    ///
-    /// This method is executed when doing abstract equality comparisons with the `==` operator.
-    ///  For more information, check <https://tc39.es/ecma262/#sec-abstract-equality-comparison>
-    #[allow(clippy::float_cmp)]
-    pub fn equals(&mut self, other: &mut Self, interpreter: &mut Interpreter) -> bool {
-        // 1. If Type(x) is the same as Type(y), then
-        //     a. Return the result of performing Strict Equality Comparison x === y.
-        if self.get_type() == other.get_type() {
-            return self.strict_equals(other);
-        }
-
-        match (self.data(), other.data()) {
-            // 2. If x is null and y is undefined, return true.
-            // 3. If x is undefined and y is null, return true.
-            _ if self.is_null_or_undefined() && other.is_null_or_undefined() => true,
-
-            // 3. If Type(x) is Number and Type(y) is String, return the result of the comparison x == ! ToNumber(y).
-            // 4. If Type(x) is String and Type(y) is Number, return the result of the comparison ! ToNumber(x) == y.
-            //
-            // https://github.com/rust-lang/rust/issues/54883
-            (ValueData::Integer(_), ValueData::String(_))
-            | (ValueData::Rational(_), ValueData::String(_))
-            | (ValueData::String(_), ValueData::Integer(_))
-            | (ValueData::String(_), ValueData::Rational(_))
-            | (ValueData::Rational(_), ValueData::Boolean(_))
-            | (ValueData::Integer(_), ValueData::Boolean(_)) => {
-                let a: &Value = self.borrow();
-                let b: &Value = other.borrow();
-                Number::equals(f64::from(a), f64::from(b))
-            }
-
-            // 6. If Type(x) is BigInt and Type(y) is String, then
-            //    a. Let n be ! StringToBigInt(y).
-            //    b. If n is NaN, return false.
-            //    c. Return the result of the comparison x == n.
-            (ValueData::BigInt(ref a), ValueData::String(ref b)) => match string_to_bigint(b) {
-                Some(ref b) => a == b,
-                None => false,
-            },
-
-            // 7. If Type(x) is String and Type(y) is BigInt, return the result of the comparison y == x.
-            (ValueData::String(ref a), ValueData::BigInt(ref b)) => match string_to_bigint(a) {
-                Some(ref a) => a == b,
-                None => false,
-            },
-
-            // 8. If Type(x) is Boolean, return the result of the comparison ! ToNumber(x) == y.
-            (ValueData::Boolean(_), _) => {
-                other.equals(&mut Value::from(self.to_integer()), interpreter)
-            }
-
-            // 9. If Type(y) is Boolean, return the result of the comparison x == ! ToNumber(y).
-            (_, ValueData::Boolean(_)) => {
-                self.equals(&mut Value::from(other.to_integer()), interpreter)
-            }
-
-            // 10. If Type(x) is either String, Number, BigInt, or Symbol and Type(y) is Object, return the result
-            // of the comparison x == ? ToPrimitive(y).
-            (ValueData::Object(_), _) => {
-                let mut primitive = interpreter.to_primitive(self, None);
-                primitive.equals(other, interpreter)
-            }
-
-            // 11. If Type(x) is Object and Type(y) is either String, Number, BigInt, or Symbol, return the result
-            // of the comparison ? ToPrimitive(x) == y.
-            (_, ValueData::Object(_)) => {
-                let mut primitive = interpreter.to_primitive(other, None);
-                primitive.equals(self, interpreter)
-            }
-
-            // 12. If Type(x) is BigInt and Type(y) is Number, or if Type(x) is Number and Type(y) is BigInt, then
-            //    a. If x or y are any of NaN, +∞, or -∞, return false.
-            //    b. If the mathematical value of x is equal to the mathematical value of y, return true; otherwise return false.
-            (ValueData::BigInt(ref a), ValueData::Rational(ref b)) => a == b,
-            (ValueData::Rational(ref a), ValueData::BigInt(ref b)) => a == b,
-            (ValueData::BigInt(ref a), ValueData::Integer(ref b)) => a == b,
-            (ValueData::Integer(ref a), ValueData::BigInt(ref b)) => a == b,
-
-            // 13. Return false.
-            _ => false,
-        }
-    }
-}
-
-/// This function takes a string and conversts it to BigInt type.
-///
-/// If the result is `NaN` than `None` is returned.
-///
-/// More information:
-///  - [ECMAScript reference][spec]
-///
-/// [spec]: https://tc39.es/ecma262/#sec-stringtobigint
-pub fn string_to_bigint(string: &str) -> Option<BigInt> {
-    if string.is_empty() {
-        return Some(BigInt::from(0));
-    }
-
-    BigInt::from_str(string).ok()
-}
-
-/// The internal comparison abstract operation SameValue(x, y),
-/// where x and y are ECMAScript language values, produces true or false.
-/// Such a comparison is performed as follows:
-///
-/// https://tc39.es/ecma262/#sec-samevalue
-/// strict mode currently compares the pointers
-pub fn same_value(x: &Value, y: &Value, strict: bool) -> bool {
-    if strict {
-        // Do both Values point to the same underlying valueData?
-        return std::ptr::eq(x.data(), y.data());
-    }
-
-    if x.get_type() != y.get_type() {
-        return false;
-    }
-
-    // TODO: check BigInt
-    // https://github.com/jasonwilliams/boa/pull/358
-    if x.is_number() {
-        return Number::same_value(f64::from(x), f64::from(y));
-    }
-
-    same_value_non_number(x, y)
-}
-
-pub fn same_value_non_number(x: &Value, y: &Value) -> bool {
-    debug_assert!(x.get_type() == y.get_type());
-    match x.get_type() {
-        "undefined" => true,
-        "null" => true,
-        "string" => {
-            if x.to_string() == y.to_string() {
-                return true;
-            }
-            false
-        }
-        "bigint" => BigInt::try_from(x).unwrap() == BigInt::try_from(y).unwrap(),
-        "boolean" => bool::from(x) == bool::from(y),
-        "object" => std::ptr::eq(x, y),
-        _ => false,
-    }
-}
 
 impl Add for Value {
     type Output = Self;
@@ -315,22 +142,3 @@ impl Neg for Value {
         }
     }
 }
-
-/// The internal comparison abstract operation SameValueZero(x, y),
-/// where x and y are ECMAScript language values, produces true or false.
-/// SameValueZero differs from SameValue only in its treatment of +0 and -0.
-///
-/// Such a comparison is performed as follows:
-///
-/// <https://tc39.es/ecma262/#sec-samevaluezero>
-pub fn same_value_zero(x: &Value, y: &Value) -> bool {
-    if x.get_type() != y.get_type() {
-        return false;
-    }
-
-    if x.is_number() {
-        return Number::same_value_zero(f64::from(x), f64::from(y));
-    }
-
-    same_value_non_number(x, y)
-}

boa/src/exec/mod.rs

@@ -31,6 +31,7 @@ use crate::{
     },
     BoaProfiler,
 };
+use std::convert::TryFrom;
 use std::{borrow::Borrow, ops::Deref};
 
 pub trait Executable {
@@ -147,7 +148,7 @@ impl Interpreter {
                 self.throw_type_error("can't convert symbol to string")?;
                 unreachable!();
             }
-            ValueData::BigInt(ref bigint) => Ok(BigInt::to_native_string(bigint)),
+            ValueData::BigInt(ref bigint) => Ok(bigint.to_string()),
             ValueData::Object(_) => {
                 let primitive = self.to_primitive(&mut value.clone(), Some("string"));
                 self.to_string(&primitive)
@@ -155,6 +156,44 @@ impl Interpreter {
         }
     }
 
+    /// Helper function.
+    #[allow(clippy::wrong_self_convention)]
+    pub fn to_bigint(&mut self, value: &Value) -> Result<BigInt, Value> {
+        match value.data() {
+            ValueData::Null => {
+                self.throw_type_error("cannot convert null to a BigInt")?;
+                unreachable!();
+            }
+            ValueData::Undefined => {
+                self.throw_type_error("cannot convert undefined to a BigInt")?;
+                unreachable!();
+            }
+            ValueData::String(ref string) => Ok(BigInt::from_string(string, self)?),
+            ValueData::Boolean(true) => Ok(BigInt::from(1)),
+            ValueData::Boolean(false) => Ok(BigInt::from(0)),
+            ValueData::Integer(num) => Ok(BigInt::from(*num)),
+            ValueData::Rational(num) => {
+                if let Ok(bigint) = BigInt::try_from(*num) {
+                    return Ok(bigint);
+                }
+                self.throw_type_error(format!(
+                    "The number {} cannot be converted to a BigInt because it is not an integer",
+                    num
+                ))?;
+                unreachable!();
+            }
+            ValueData::BigInt(b) => Ok(b.clone()),
+            ValueData::Object(_) => {
+                let primitive = self.to_primitive(&mut value.clone(), Some("number"));
+                self.to_bigint(&primitive)
+            }
+            ValueData::Symbol(_) => {
+                self.throw_type_error("cannot convert Symbol to a BigInt")?;
+                unreachable!();
+            }
+        }
+    }
+
     /// Converts an array object into a rust vector of values.
     ///
     /// This is useful for the spread operator, for any other object an `Err` is returned

boa/src/exec/tests.rs

@@ -1,4 +1,4 @@
-use crate::{exec, exec::Interpreter, forward, realm::Realm};
+use crate::{builtins::Value, exec, exec::Interpreter, forward, realm::Realm};
 
 #[test]
 fn empty_let_decl_undefined() {
@@ -753,3 +753,27 @@ fn function_decl_hoisting() {
     "#;
     assert_eq!(&exec(scenario), "5");
 }
+
+#[test]
+fn to_bigint() {
+    let realm = Realm::create();
+    let mut engine = Interpreter::new(realm);
+
+    assert!(engine.to_bigint(&Value::null()).is_err());
+    assert!(engine.to_bigint(&Value::undefined()).is_err());
+    assert!(engine.to_bigint(&Value::integer(55)).is_ok());
+    assert!(engine.to_bigint(&Value::rational(10.0)).is_ok());
+    assert!(engine.to_bigint(&Value::string("100")).is_ok());
+}
+
+#[test]
+fn to_string() {
+    let realm = Realm::create();
+    let mut engine = Interpreter::new(realm);
+
+    assert_eq!(engine.to_string(&Value::null()).unwrap(), "null");
+    assert_eq!(engine.to_string(&Value::undefined()).unwrap(), "undefined");
+    assert_eq!(engine.to_string(&Value::integer(55)).unwrap(), "55");
+    assert_eq!(engine.to_string(&Value::rational(55.0)).unwrap(), "55");
+    assert_eq!(engine.to_string(&Value::string("hello")).unwrap(), "hello");
+}

boa/src/syntax/ast/bigint.rs

@@ -1,246 +0,0 @@
-//! This module implements the `BigInt` structure, which represents the BigInt values in JavaScript.
-//!
-//! More information:
-//!  - [ECMAScript reference][spec]
-//!  - [MDN documentation][mdn]
-//!
-//! [spec]: https://tc39.es/ecma262/#sec-bigint-objects
-//! [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt
-
-use gc::{unsafe_empty_trace, Finalize, Trace};
-use num_traits::cast::{FromPrimitive, ToPrimitive};
-use num_traits::pow::Pow;
-
-use std::convert::TryFrom;
-use std::str::FromStr;
-
-#[cfg(feature = "serde")]
-use serde::{Deserialize, Serialize};
-
-#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[derive(Clone, Hash, PartialEq, Eq, PartialOrd, Ord, Default)]
-pub struct BigInt(num_bigint::BigInt);
-
-impl BigInt {
-    /// Returns the inner bigint structure.
-    #[inline]
-    pub fn into_inner(self) -> num_bigint::BigInt {
-        self.0
-    }
-
-    /// Converts a string to a BigInt with the specified radix.
-    #[inline]
-    pub fn from_str_radix(buf: &str, radix: u32) -> Option<Self> {
-        num_bigint::BigInt::parse_bytes(buf.as_bytes(), radix).map(Self)
-    }
-
-    #[inline]
-    pub fn pow(self, other: &Self) -> Self {
-        Self(
-            self.0.pow(
-                other
-                    .0
-                    .to_biguint()
-                    .expect("RangeError: \"BigInt negative exponent\""),
-            ),
-        )
-    }
-
-    /// Converts the BigInt to a f64 type.
-    ///
-    /// Returns `std::f64::INFINITY` if the BigInt is too big.
-    #[inline]
-    pub fn to_f64(&self) -> f64 {
-        self.0.to_f64().unwrap_or(std::f64::INFINITY)
-    }
-}
-
-impl From<i64> for BigInt {
-    fn from(n: i64) -> BigInt {
-        BigInt(num_bigint::BigInt::from(n))
-    }
-}
-
-impl From<i32> for BigInt {
-    fn from(n: i32) -> BigInt {
-        BigInt(num_bigint::BigInt::from(n))
-    }
-}
-
-#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, PartialOrd, Ord)]
-pub struct TryFromF64Error;
-
-impl std::fmt::Display for TryFromF64Error {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "Could not convert f64 value to a BigInt type")
-    }
-}
-
-impl TryFrom<f64> for BigInt {
-    type Error = TryFromF64Error;
-
-    fn try_from(n: f64) -> Result<Self, Self::Error> {
-        match num_bigint::BigInt::from_f64(n) {
-            Some(bigint) => Ok(BigInt(bigint)),
-            None => Err(TryFromF64Error),
-        }
-    }
-}
-
-#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, PartialOrd, Ord)]
-pub struct ParseBigIntError;
-
-impl std::fmt::Display for ParseBigIntError {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "Could not parse to BigInt type")
-    }
-}
-
-impl FromStr for BigInt {
-    type Err = ParseBigIntError;
-
-    fn from_str(string: &str) -> Result<Self, Self::Err> {
-        match num_bigint::BigInt::from_str(string) {
-            Ok(bigint) => Ok(BigInt(bigint)),
-            Err(_) => Err(ParseBigIntError),
-        }
-    }
-}
-
-macro_rules! impl_bigint_operator {
-    ($op:ident, $op_method:ident, $assign_op:ident, $assign_op_method:ident) => {
-        impl std::ops::$op for BigInt {
-            type Output = Self;
-
-            fn $op_method(mut self, other: Self) -> Self {
-                std::ops::$assign_op::$assign_op_method(&mut self.0, other.0);
-                self
-            }
-        }
-    };
-}
-
-impl_bigint_operator!(Add, add, AddAssign, add_assign);
-impl_bigint_operator!(Sub, sub, SubAssign, sub_assign);
-impl_bigint_operator!(Mul, mul, MulAssign, mul_assign);
-impl_bigint_operator!(Div, div, DivAssign, div_assign);
-impl_bigint_operator!(Rem, rem, RemAssign, rem_assign);
-impl_bigint_operator!(BitAnd, bitand, BitAndAssign, bitand_assign);
-impl_bigint_operator!(BitOr, bitor, BitOrAssign, bitor_assign);
-impl_bigint_operator!(BitXor, bitxor, BitXorAssign, bitxor_assign);
-
-impl std::ops::Shr for BigInt {
-    type Output = Self;
-
-    fn shr(mut self, other: Self) -> Self::Output {
-        use std::ops::ShlAssign;
-        use std::ops::ShrAssign;
-
-        if let Some(n) = other.0.to_i32() {
-            if n > 0 {
-                self.0.shr_assign(n as usize)
-            } else {
-                self.0.shl_assign(n.abs() as usize)
-            }
-
-            return self;
-        }
-
-        panic!("RangeError: Maximum BigInt size exceeded");
-    }
-}
-
-impl std::ops::Shl for BigInt {
-    type Output = Self;
-
-    fn shl(mut self, other: Self) -> Self::Output {
-        use std::ops::ShlAssign;
-        use std::ops::ShrAssign;
-
-        if let Some(n) = other.0.to_i32() {
-            if n > 0 {
-                self.0.shl_assign(n as usize)
-            } else {
-                self.0.shr_assign(n.abs() as usize)
-            }
-
-            return self;
-        }
-
-        panic!("RangeError: Maximum BigInt size exceeded");
-    }
-}
-
-impl std::ops::Neg for BigInt {
-    type Output = Self;
-
-    fn neg(self) -> Self::Output {
-        Self(-self.0)
-    }
-}
-
-impl PartialEq<i32> for BigInt {
-    fn eq(&self, other: &i32) -> bool {
-        self.0 == num_bigint::BigInt::from(*other)
-    }
-}
-
-impl PartialEq<BigInt> for i32 {
-    fn eq(&self, other: &BigInt) -> bool {
-        num_bigint::BigInt::from(*self) == other.0
-    }
-}
-
-impl PartialEq<f64> for BigInt {
-    fn eq(&self, other: &f64) -> bool {
-        if other.fract() != 0.0 {
-            return false;
-        }
-
-        self.0 == num_bigint::BigInt::from(*other as i64)
-    }
-}
-
-impl PartialEq<BigInt> for f64 {
-    fn eq(&self, other: &BigInt) -> bool {
-        if self.fract() != 0.0 {
-            return false;
-        }
-
-        num_bigint::BigInt::from(*self as i64) == other.0
-    }
-}
-
-impl std::fmt::Debug for BigInt {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "{}", self.0)
-    }
-}
-
-impl std::fmt::Display for BigInt {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "{}", self.0)
-    }
-}
-
-impl std::ops::Deref for BigInt {
-    type Target = num_bigint::BigInt;
-
-    fn deref(&self) -> &Self::Target {
-        &self.0
-    }
-}
-
-impl std::ops::DerefMut for BigInt {
-    fn deref_mut(&mut self) -> &mut Self::Target {
-        &mut self.0
-    }
-}
-
-impl Finalize for BigInt {}
-unsafe impl Trace for BigInt {
-    // BigInt type implements an empty trace becasue the inner structure
-    // `num_bigint::BigInt` does not implement `Trace` trait.
-    // If it did this would be unsound.
-    unsafe_empty_trace!();
-}

boa/src/syntax/ast/constant.rs

@@ -7,7 +7,7 @@
 //! [spec]: https://tc39.es/ecma262/#sec-primary-expression-literals
 //! [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Grammar_and_types#Literals
 
-use crate::syntax::ast::bigint::BigInt;
+use crate::builtins::bigint::BigInt;
 use gc::{Finalize, Trace};
 use std::fmt::{Display, Formatter, Result};
 

boa/src/syntax/ast/mod.rs

@@ -1,6 +1,5 @@
 //! The Javascript Abstract Syntax Tree.
 
-pub mod bigint;
 pub mod constant;
 pub mod keyword;
 pub mod node;

boa/src/syntax/ast/token.rs

@@ -5,8 +5,9 @@
 //!
 //! [spec]: https://tc39.es/ecma262/#sec-tokens
 
+use crate::builtins::BigInt;
 use crate::syntax::{
-    ast::{bigint::BigInt, Keyword, Punctuator, Span},
+    ast::{Keyword, Punctuator, Span},
     lexer::LexerError,
 };
 use bitflags::bitflags;

boa/src/syntax/lexer/mod.rs

@@ -6,7 +6,7 @@
 #[cfg(test)]
 mod tests;
 
-use crate::syntax::ast::bigint::BigInt;
+use crate::builtins::BigInt;
 use crate::{
     syntax::ast::{
         token::{NumericLiteral, Token, TokenKind},
@@ -442,7 +442,7 @@ impl<'a> Lexer<'a> {
         let num = match kind {
                 NumericKind::BigInt(base) => {
                     NumericLiteral::BigInt(
-                        BigInt::from_str_radix(&buf, base as u32).expect("Could not conver to BigInt")
+                        BigInt::from_string_radix(&buf, base as u32).expect("Could not conver to BigInt")
                         )
                 }
                 NumericKind::Rational /* base: 10 */ => {