ensure that you can't use Enter to invoke the Switch

And a bunch of keyPress and keyboard related shenanigans

packages/@headlessui-react/src/components/switch/switch.test.tsx

@@ -156,6 +156,24 @@ describe('Keyboard interactions', () => {
     })
   })
 
+  describe('`Enter` key', () => {
+    it('should not be possible to use Enter to toggle the Switch', async () => {
+      const handleChange = jest.fn()
+      render(<Switch checked={false} onChange={handleChange} />)
+
+      // Ensure checkbox is off
+      assertSwitch({ state: SwitchState.Off })
+
+      // Focus the switch
+      getSwitch()?.focus()
+
+      // Try to toggle
+      await press(Keys.Enter)
+
+      expect(handleChange).not.toHaveBeenCalled()
+    })
+  })
+
   describe('`Tab` key', () => {
     it('should be possible to tab away from the Switch', async () => {
       render(

packages/@headlessui-react/src/components/switch/switch.tsx

@@ -55,7 +55,14 @@ const DEFAULT_SWITCH_TAG = 'button'
 
 type SwitchRenderPropArg = { checked: boolean }
 
-type SwitchPropsWeControl = 'id' | 'role' | 'tabIndex' | 'aria-checked' | 'onClick' | 'onKeyUp'
+type SwitchPropsWeControl =
+  | 'id'
+  | 'role'
+  | 'tabIndex'
+  | 'aria-checked'
+  | 'onClick'
+  | 'onKeyUp'
+  | 'onKeyPress'
 
 export function Switch<TTag extends React.ElementType = typeof DEFAULT_SWITCH_TAG>(
   props: Props<
@@ -84,14 +91,18 @@ export function Switch<TTag extends React.ElementType = typeof DEFAULT_SWITCH_TA
   )
   const handleKeyUp = React.useCallback(
     (event: React.KeyboardEvent<HTMLElement>) => {
-      if (event.key === Keys.Space) {
-        event.preventDefault()
-        toggle()
-      }
+      if (event.key !== Keys.Tab) event.preventDefault()
+      if (event.key === Keys.Space) toggle()
     },
     [toggle]
   )
 
+  // This is needed so that we can "cancel" the click event when we use the `Enter` key on a button.
+  const handleKeyPress = React.useCallback(
+    (event: React.KeyboardEvent<HTMLElement>) => event.preventDefault(),
+    []
+  )
+
   const propsBag = React.useMemo<SwitchRenderPropArg>(() => ({ checked }), [checked])
   const propsWeControl = {
     id,
@@ -103,6 +114,7 @@ export function Switch<TTag extends React.ElementType = typeof DEFAULT_SWITCH_TA
     'aria-labelledby': groupContext?.label?.id,
     onClick: handleClick,
     onKeyUp: handleKeyUp,
+    onKeyPress: handleKeyPress,
   }
 
   return render({ ...passThroughProps, ...propsWeControl }, propsBag, DEFAULT_SWITCH_TAG)