From 8dcfff09256b24bb6032a8be1295b8b54ec16558 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Javier=20Mu=C3=B1oz=20Tous?= <javimtib92@gmail.com>
Date: Thu, 5 Sep 2024 02:21:35 +0200
Subject: [PATCH] refactor(biome_js_parser/syntax): use enumflags2 for
 `TypeContext` (#3789)

---
 .../src/syntax/typescript/types.rs            | 94 +++++++++++++------
 1 file changed, 66 insertions(+), 28 deletions(-)

diff --git a/crates/biome_js_parser/src/syntax/typescript/types.rs b/crates/biome_js_parser/src/syntax/typescript/types.rs
index 07ab297d0a35..9e4bcd9e895f 100644
--- a/crates/biome_js_parser/src/syntax/typescript/types.rs
+++ b/crates/biome_js_parser/src/syntax/typescript/types.rs
@@ -1,3 +1,5 @@
+use std::ops::{BitOr, Sub};
+
 use crate::parser::{RecoveryError, RecoveryResult};
 use crate::prelude::*;
 use crate::state::{EnterType, SignatureFlags};
@@ -27,7 +29,7 @@ use crate::syntax::typescript::ts_parse_error::{
     ts_in_out_modifier_cannot_appear_on_a_type_parameter,
 };
 use biome_parser::parse_lists::{ParseNodeList, ParseSeparatedList};
-use bitflags::bitflags;
+use enumflags2::{bitflags, make_bitflags, BitFlags};
 use smallvec::SmallVec;
 
 use crate::lexer::{JsLexContext, JsReLexContext};
@@ -41,34 +43,54 @@ use biome_js_syntax::{JsSyntaxKind::*, *};
 
 use super::{expect_ts_index_signature_member, is_at_ts_index_signature_member, MemberParent};
 
-bitflags! {
-    /// Context tracking state that applies to the parsing of all types
-    #[derive(Debug, Default, Copy, Clone, Eq, PartialEq)]
-    pub(crate) struct TypeContext: u8 {
-        /// Whether conditional types `extends string ? string : number` are allowed in the current context.
-        ///
-        /// By default, conditional types are allowed.
-        const DISALLOW_CONDITIONAL_TYPES = 1 << 0;
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[bitflags]
+#[repr(u8)]
+enum ContextFlag {
+    DisallowConditionalTypes = 1 << 0,
+    AllowInOutModifier = 1 << 1,
+    AllowConstModifier = 1 << 2,
+    InConditionalExtends = 1 << 3,
+    TypeOrInterfaceDeclaration = 1 << 4,
+}
+
+/// Context tracking state that applies to the parsing of all types
+#[derive(Debug, Default, Copy, Clone)]
+pub(crate) struct TypeContext(BitFlags<ContextFlag>);
+
+impl TypeContext {
+    /// Whether conditional types `extends string ? string : number` are allowed in the current context.
+    ///
+    /// By default, conditional types are allowed.
+    pub const DISALLOW_CONDITIONAL_TYPES: Self =
+        Self(make_bitflags!(ContextFlag::{DisallowConditionalTypes}));
+
+    /// Whether 'in' and 'out' modifiers are allowed in the current context.
+    ///
+    /// By default, 'in' and 'out' modifiers are not allowed.
+    pub const ALLOW_IN_OUT_MODIFIER: Self = Self(make_bitflags!(ContextFlag::{AllowInOutModifier}));
 
-        /// Whether 'in' and 'out' modifiers are allowed in the current context.
-        ///
-        /// By default, 'in' and 'out' modifiers are not allowed.
-        const ALLOW_IN_OUT_MODIFIER = 1 << 1;
+    /// Whether 'const' modifier is allowed in the current context.
+    ///
+    /// By default, 'const' modifier is not allowed.
+    pub const ALLOW_CONST_MODIFIER: Self = Self(make_bitflags!(ContextFlag::{AllowConstModifier}));
 
-        /// Whether 'const' modifier is allowed in the current context.
-        ///
-        /// By default, 'const' modifier is not allowed.
-        const ALLOW_CONST_MODIFIER = 1 << 2;
+    /// Whether the parser is inside a conditional extends
+    pub const IN_CONDITIONAL_EXTENDS: Self =
+        Self(make_bitflags!(ContextFlag::{InConditionalExtends}));
 
-        /// Whether the parser is inside a conditional extends
-        const IN_CONDITIONAL_EXTENDS = 1 << 3;
+    /// Whether the current context is within a type or interface declaration
+    pub const TYPE_OR_INTERFACE_DECLARATION: Self =
+        Self(make_bitflags!(ContextFlag::{TypeOrInterfaceDeclaration}));
 
-        /// Whether the current context is within a type or interface declaration
-        const TYPE_OR_INTERFACE_DECLARATION = 1 << 4;
+    pub const fn empty() -> Self {
+        Self(BitFlags::EMPTY)
+    }
+
+    pub fn contains(&self, other: impl Into<TypeContext>) -> bool {
+        self.0.contains(other.into().0)
     }
-}
 
-impl TypeContext {
     pub(crate) fn and_allow_conditional_types(self, allow: bool) -> Self {
         self.and(TypeContext::DISALLOW_CONDITIONAL_TYPES, !allow)
     }
@@ -89,23 +111,23 @@ impl TypeContext {
         self.and(TypeContext::TYPE_OR_INTERFACE_DECLARATION, allow)
     }
 
-    pub(crate) const fn is_conditional_type_allowed(&self) -> bool {
+    pub(crate) fn is_conditional_type_allowed(&self) -> bool {
         !self.contains(TypeContext::DISALLOW_CONDITIONAL_TYPES)
     }
 
-    pub(crate) const fn is_in_out_modifier_allowed(&self) -> bool {
+    pub(crate) fn is_in_out_modifier_allowed(&self) -> bool {
         self.contains(TypeContext::ALLOW_IN_OUT_MODIFIER)
     }
 
-    pub(crate) const fn is_const_modifier_allowed(&self) -> bool {
+    pub(crate) fn is_const_modifier_allowed(&self) -> bool {
         self.contains(TypeContext::ALLOW_CONST_MODIFIER)
     }
 
-    pub(crate) const fn in_conditional_extends(&self) -> bool {
+    pub(crate) fn in_conditional_extends(&self) -> bool {
         self.contains(TypeContext::IN_CONDITIONAL_EXTENDS)
     }
 
-    pub(crate) const fn is_in_type_or_interface_declaration(&self) -> bool {
+    pub(crate) fn is_in_type_or_interface_declaration(&self) -> bool {
         self.contains(TypeContext::TYPE_OR_INTERFACE_DECLARATION)
     }
 
@@ -119,6 +141,22 @@ impl TypeContext {
     }
 }
 
+impl BitOr for TypeContext {
+    type Output = Self;
+
+    fn bitor(self, rhs: Self) -> Self::Output {
+        Self(self.0 | rhs.0)
+    }
+}
+
+impl Sub for TypeContext {
+    type Output = Self;
+
+    fn sub(self, rhs: Self) -> Self::Output {
+        Self(self.0 & !rhs.0)
+    }
+}
+
 pub(crate) fn is_reserved_type_name(name: &str) -> bool {
     name.len() <= 6
         && name.len() >= 3