chore: reuse is_function helper (#15467)

Rich-Harris · web-flow · commit 1c0e24013fff · 2025-03-10T11:22:21.000-04:00
diff --git a/packages/svelte/src/compiler/phases/2-analyze/visitors/Attribute.js b/packages/svelte/src/compiler/phases/2-analyze/visitors/Attribute.js
@@ -162,16 +162,8 @@ function get_delegated_event(event_name, handler, context) {
 			return unhoisted;
 		}
 
-		if (binding !== null && binding.initial !== null && !binding.updated) {
-			const binding_type = binding.initial.type;
-
-			if (
-				binding_type === 'ArrowFunctionExpression' ||
-				binding_type === 'FunctionDeclaration' ||
-				binding_type === 'FunctionExpression'
-			) {
-				target_function = binding.initial;
-			}
+		if (binding?.is_function()) {
+			target_function = binding.initial;
 		}
 	}
 
diff --git a/packages/svelte/src/compiler/phases/scope.js b/packages/svelte/src/compiler/phases/scope.js
@@ -1,4 +1,4 @@
-/** @import { ClassDeclaration, Expression, FunctionDeclaration, Identifier, ImportDeclaration, MemberExpression, Node, Pattern, VariableDeclarator } from 'estree' */
+/** @import { ArrowFunctionExpression, ClassDeclaration, Expression, FunctionDeclaration, FunctionExpression, Identifier, ImportDeclaration, MemberExpression, Node, Pattern, VariableDeclarator } from 'estree' */
 /** @import { Context, Visitor } from 'zimmerframe' */
 /** @import { AST, BindingKind, DeclarationKind } from '#compiler' */
 import is_reference from 'is-reference';
@@ -80,19 +80,23 @@ export class Binding {
 		return this.mutated || this.reassigned;
 	}
 
+	/**
+	 * @returns {this is Binding & { initial: ArrowFunctionExpression | FunctionDeclaration | FunctionExpression }}
+	 */
 	is_function() {
-		if (this.reassigned) {
+		if (this.updated) {
 			// even if it's reassigned to another function,
 			// we can't use it directly as e.g. an event handler
 			return false;
 		}
 
-		if (this.declaration_kind === 'function') {
-			return true;
-		}
-
 		const type = this.initial?.type;
-		return type === 'ArrowFunctionExpression' || type === 'FunctionExpression';
+
+		return (
+			type === 'ArrowFunctionExpression' ||
+			type === 'FunctionExpression' ||
+			type === 'FunctionDeclaration'
+		);
 	}
 }
 

Original file line number	Diff line number	Diff line change
`@@ -162,16 +162,8 @@ function get_delegated_event(event_name, handler, context) {`
`162`	`162`	`return unhoisted;`
`163`	`163`	`}`
`164`	`164`
`165`		`- if (binding !== null && binding.initial !== null && !binding.updated) {`
`166`		`- const binding_type = binding.initial.type;`
`167`		`-`
`168`		`- if (`
`169`		`- binding_type === 'ArrowFunctionExpression' \|\|`
`170`		`- binding_type === 'FunctionDeclaration' \|\|`
`171`		`- binding_type === 'FunctionExpression'`
`172`		`- ) {`
`173`		`- target_function = binding.initial;`
`174`		`- }`
	`165`	`+ if (binding?.is_function()) {`
	`166`	`+ target_function = binding.initial;`
`175`	`167`	`}`
`176`	`168`	`}`
`177`	`169`