refactor(ast): check whether there is a single quasi in TemplateLiteral::quasi (#12265)

As the changes show, `TemplateLiteral::quasi` is always paired with a check to use, that check is whether there is only one single `quasi` in this `TemplateLiteral`. This PR is to put this check into the `TemplateLiteral::quasi` API, so that we can simplify the use of `TemplateLiteral::quasi`

crates/oxc_ast/src/ast_impl/js.rs

@@ -544,12 +544,12 @@ impl<'a> TemplateLiteral<'a> {
     /// - `` `foo` `` => `true`
     /// - `` `foo${bar}qux` `` => `false`
     pub fn is_no_substitution_template(&self) -> bool {
-        self.expressions.is_empty() && self.quasis.len() == 1
+        self.quasis.len() == 1
     }
 
     /// Get single quasi from `template`
     pub fn quasi(&self) -> Option<Atom<'a>> {
-        self.quasis.first().and_then(|quasi| quasi.value.cooked)
+        if self.is_no_substitution_template() { self.quasis[0].value.cooked } else { None }
     }
 }
 

crates/oxc_ecmascript/src/side_effects/may_have_side_effects.rs

@@ -417,13 +417,9 @@ impl<'a> MayHaveSideEffects<'a> for ComputedMemberExpression<'a> {
             Expression::StringLiteral(s) => {
                 property_access_may_have_side_effects(&self.object, &s.value, ctx)
             }
-            Expression::TemplateLiteral(t) if t.is_no_substitution_template() => {
-                property_access_may_have_side_effects(
-                    &self.object,
-                    &t.quasi().expect("template literal must have at least one quasi"),
-                    ctx,
-                )
-            }
+            Expression::TemplateLiteral(t) => t.quasi().is_some_and(|quasi| {
+                property_access_may_have_side_effects(&self.object, &quasi, ctx)
+            }),
             Expression::NumericLiteral(n) => !n.value.to_integer_index().is_some_and(|n| {
                 !integer_index_property_access_may_have_side_effects(&self.object, n, ctx)
             }),

crates/oxc_ecmascript/src/to_primitive.rs

@@ -93,10 +93,7 @@ pub fn maybe_object_with_to_primitive_related_properties_overridden(
                 matches!(str.value.as_str(), "toString" | "valueOf")
             }
             PropertyKey::TemplateLiteral(temp) => {
-                !temp.is_no_substitution_template()
-                    || temp
-                        .quasi()
-                        .is_some_and(|val| matches!(val.as_str(), "toString" | "valueOf"))
+                temp.quasi().is_some_and(|val| matches!(val.as_str(), "toString" | "valueOf"))
             }
             _ => true,
         },

crates/oxc_linter/src/ast_util.rs

@@ -308,9 +308,7 @@ pub fn extract_regex_flags<'a>(
     }
     let flag_arg = match &args[1] {
         Argument::StringLiteral(flag_arg) => flag_arg.value,
-        Argument::TemplateLiteral(template) if template.is_no_substitution_template() => {
-            template.quasi().expect("no-substitution templates always have a quasi")
-        }
+        Argument::TemplateLiteral(template) => template.quasi()?,
         _ => return None,
     };
     let mut flags = RegExpFlags::empty();

crates/oxc_linter/src/rules/eslint/valid_typeof.rs

@@ -124,8 +124,8 @@ impl Rule for ValidTypeof {
         }
 
         if let Expression::TemplateLiteral(template) = sibling {
-            if template.expressions.is_empty() {
-                if template.quasi().is_some_and(|value| !VALID_TYPES.contains(&value.as_str())) {
+            if let Some(quasi) = template.quasi() {
+                if !VALID_TYPES.contains(&quasi.as_str()) {
                     ctx.diagnostic(invalid_value(None, sibling.span()));
                 }
                 return;

crates/oxc_linter/src/rules/jest/valid_title.rs

@@ -180,9 +180,6 @@ impl ValidTitle {
                 );
             }
             Argument::TemplateLiteral(template_literal) => {
-                if !template_literal.is_no_substitution_template() {
-                    return;
-                }
                 if let Some(quasi) = template_literal.quasi() {
                     validate_title(
                         quasi.as_str(),

crates/oxc_linter/src/rules/react/button_has_type.rs

@@ -180,15 +180,9 @@ impl ButtonHasType {
             Expression::StringLiteral(str) => {
                 self.is_valid_button_type_prop_string_literal(str.value.as_str())
             }
-            Expression::TemplateLiteral(template_literal) => {
-                if !template_literal.is_no_substitution_template() {
-                    return false;
-                }
-                if let Some(quasi) = template_literal.quasi() {
-                    return self.is_valid_button_type_prop_string_literal(quasi.as_str());
-                }
-                false
-            }
+            Expression::TemplateLiteral(template_literal) => template_literal
+                .quasi()
+                .is_some_and(|quasi| self.is_valid_button_type_prop_string_literal(quasi.as_str())),
             Expression::ConditionalExpression(conditional_expr) => {
                 self.is_valid_button_type_prop_expression(&conditional_expr.consequent)
                     && self.is_valid_button_type_prop_expression(&conditional_expr.alternate)

crates/oxc_linter/src/rules/react/jsx_curly_brace_presence.rs

@@ -462,8 +462,9 @@ impl JsxCurlyBracePresence {
                 }
             }
             Expression::TemplateLiteral(template) => {
-                if allowed.is_never() && template.is_no_substitution_template() {
-                    let string = template.quasi().unwrap();
+                if allowed.is_never()
+                    && let Some(string) = template.quasi()
+                {
                     if contains_quote_characters(string.as_str())
                         || is_allowed_string_like(
                             ctx,

crates/oxc_linter/src/utils/express.rs

@@ -34,8 +34,8 @@ pub fn as_endpoint_registration<'a, 'n>(
         Expression::StringLiteral(path) => {
             Some((Some(path.value), &call.arguments.as_slice()[1..]))
         }
-        Expression::TemplateLiteral(template) if template.is_no_substitution_template() => {
-            Some((template.quasi(), &call.arguments.as_slice()[1..]))
+        Expression::TemplateLiteral(template) => {
+            template.quasi().map(|quasi| (Some(quasi), &call.arguments.as_slice()[1..]))
         }
         _ => Some((None, call.arguments.as_slice())),
     }

crates/oxc_linter/src/utils/jest.rs

@@ -3,7 +3,7 @@ use std::borrow::Cow;
 use oxc_ast::{
     AstKind,
     ast::{
-        CallExpression, Expression, ImportDeclaration, ImportDeclarationSpecifier, TemplateLiteral,
+        CallExpression, Expression, ImportDeclaration, ImportDeclarationSpecifier,
         match_member_expression,
     },
 };
@@ -271,8 +271,10 @@ pub fn get_node_name_vec<'a>(expr: &'a Expression<'a>) -> Vec<Cow<'a, str>> {
         Expression::StringLiteral(string_literal) => {
             chain.push(Cow::Borrowed(&string_literal.value));
         }
-        Expression::TemplateLiteral(template_literal) if is_pure_string(template_literal) => {
-            chain.push(Cow::Borrowed(template_literal.quasi().unwrap().as_str()));
+        Expression::TemplateLiteral(template_literal) => {
+            if let Some(quasi) = template_literal.quasi() {
+                chain.push(Cow::Borrowed(quasi.as_str()));
+            }
         }
         Expression::TaggedTemplateExpression(tagged_expr) => {
             chain.extend(get_node_name_vec(&tagged_expr.tag));
@@ -294,10 +296,6 @@ pub fn get_node_name_vec<'a>(expr: &'a Expression<'a>) -> Vec<Cow<'a, str>> {
     chain
 }
 
-fn is_pure_string(template_literal: &TemplateLiteral) -> bool {
-    template_literal.expressions.is_empty() && template_literal.quasis.len() == 1
-}
-
 pub fn is_equality_matcher(matcher: &KnownMemberExpressionProperty) -> bool {
     matcher.is_name_equal("toBe")
         || matcher.is_name_equal("toEqual")

crates/oxc_linter/src/utils/jest/parse_jest_fn.rs

@@ -13,7 +13,7 @@ use oxc_span::Span;
 
 use crate::{
     context::LintContext,
-    utils::jest::{JestFnKind, JestGeneralFnKind, PossibleJestNode, is_pure_string},
+    utils::jest::{JestFnKind, JestGeneralFnKind, PossibleJestNode},
     utils::valid_vitest_fn::is_valid_vitest_call,
 };
 
@@ -554,7 +554,9 @@ fn recurse_extend_node_chain<'a>(
                 span: string_literal.span,
             });
         }
-        Expression::TemplateLiteral(template_literal) if is_pure_string(template_literal) => {
+        Expression::TemplateLiteral(template_literal)
+            if template_literal.is_no_substitution_template() =>
+        {
             chain.push(KnownMemberExpressionProperty {
                 element: MemberExpressionElement::Expression(expr),
                 parent: *parent,

crates/oxc_linter/src/utils/unicorn.rs

@@ -181,8 +181,7 @@ pub fn is_same_expression(left: &Expression, right: &Expression, ctx: &LintConte
         }
         (Expression::StringLiteral(string_lit), Expression::TemplateLiteral(template_lit))
         | (Expression::TemplateLiteral(template_lit), Expression::StringLiteral(string_lit)) => {
-            return template_lit.is_no_substitution_template()
-                && string_lit.value == template_lit.quasi().unwrap();
+            return template_lit.quasi().is_some_and(|val| val.as_str() == string_lit.value);
         }
         (Expression::TemplateLiteral(left_str), Expression::TemplateLiteral(right_str)) => {
             return left_str.quasis.content_eq(&right_str.quasis)
@@ -304,9 +303,7 @@ pub fn is_same_member_expression(
             // ex) x[/regex/] === x[`/regex/`]
             (Expression::TemplateLiteral(template_lit), Expression::RegExpLiteral(regex_lit))
             | (Expression::RegExpLiteral(regex_lit), Expression::TemplateLiteral(template_lit)) => {
-                if !(template_lit.is_no_substitution_template()
-                    && template_lit.quasi().unwrap() == regex_lit.raw.as_ref().unwrap())
-                {
+                if !template_lit.quasi().is_some_and(|val| val == regex_lit.raw.as_ref().unwrap()) {
                     return false;
                 }
             }