fix: falsy attachments types (#15939)

paoloricciuti · web-flow · commit 60b22ab933c4 · 2025-05-17T10:07:21.000+02:00
diff --git a/.changeset/chilled-otters-hear.md b/.changeset/chilled-otters-hear.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: falsy attachments types
diff --git a/packages/svelte/elements.d.ts b/packages/svelte/elements.d.ts
@@ -863,8 +863,8 @@ export interface HTMLAttributes<T extends EventTarget> extends AriaAttributes, D
 	// allow any data- attribute
 	[key: `data-${string}`]: any;
 
-	// allow any attachment
-	[key: symbol]: Attachment<T>;
+	// allow any attachment and falsy values (by using false we prevent the usage of booleans values by themselves)
+	[key: symbol]: Attachment<T> | false | undefined | null;
 }
 
 export type HTMLAttributeAnchorTarget = '_self' | '_blank' | '_parent' | '_top' | (string & {});

-Original file line number
+Diff line change
@@ @@ -0,0 +1,5 @@ @@
 +---
 +'svelte': patch
 +---
++
 +fix: falsy attachments types
Original file line number	Diff line number	Diff line change
`@@ -863,8 +863,8 @@ export interface HTMLAttributes<T extends EventTarget> extends AriaAttributes, D`
`863`	`863`	`// allow any data- attribute`
`864`	`864`	[key: `data-${string}`]: any;
`865`	`865`
`866`		`- // allow any attachment`
`867`		`- [key: symbol]: Attachment<T>;`
	`866`	`+ // allow any attachment and falsy values (by using false we prevent the usage of booleans values by themselves)`
	`867`	`+ [key: symbol]: Attachment<T> \| false \| undefined \| null;`
`868`	`868`	`}`
`869`	`869`
`870`	`870`	`export type HTMLAttributeAnchorTarget = '_self' \| '_blank' \| '_parent' \| '_top' \| (string & {});`