Incorrect Type Definition for popover Attribute in SvelteKit

[karanravindra]

Describe the bug

Description:
The popover attribute does not have the correct type definition in SvelteKit's typings. According to the MDN documentation, the popover attribute is a boolean attribute when used without a value. When present without a value, it should default to "auto" instead of requiring an explicit value.

Example Code

This code should be valid, but TypeScript reports an error:

<button popovertarget="popover-div">Click me</button>
<div popover id="popover-div">
	...
</div>

Error Message

Type 'true' is not assignable to type '"" | "auto" | "manual" | null | undefined'.ts(2322)
(property) popover?: "" | "auto" | "manual" | null | undefined

Expected Behavior

• The popover attribute should allow popover={true} as valid, reflecting its boolean HTML attribute behavior.
• If popover is present without a value, it should default to "auto" rather than throwing a TypeScript error.

Suggested Fix

Update the type definition in SvelteKit’s typings to:

• Accept true, allowing popover={true}.
• Default to "auto" when popover is used without a value.

Reproduction

<button popovertarget="popover-div">Click me</button>
<div popover id="popover-div">
	...
</div>

Logs

System Info

System:
    OS: macOS 15.3
    CPU: (11) arm64 Apple M3 Pro
    Memory: 183.48 MB / 18.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 22.12.0 - ~/.config/.nvm/versions/node/v22.12.0/bin/node
    npm: 10.9.0 - ~/.config/.nvm/versions/node/v22.12.0/bin/npm
    pnpm: 9.15.2 - /opt/homebrew/bin/pnpm
  Browsers:
    Chrome: 133.0.6943.53
    Safari: 18.3

Severity

annoyance

[dummdidumm]

popover is not a boolean attribute, as such not allowing popover={true} is correct. We need to adjust code in language tools to infer popover as popover={''}