Added never return types to selector within() signatures

JJWesterkamp · Apr 11, 2021 · 061fced · 061fced
1 parent efdfb6b
commit 061fced
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Showing 3 changed files with 4 additions and 4 deletions.
diff --git a/src/index.ts b/src/index.ts
@@ -18,7 +18,7 @@ const EventDelegation: AskRoot = {
     // Create one delegated event listener for a specified root element.
     // ----------------------------------------------------------------------------------------
 
-    within(rootOrSelector: string | Element): AskEvent<any, 'SINGLE'> {
+    within(rootOrSelector: string | Element): AskEvent<any, 'SINGLE'> | never {
         return createBuilder(normalizeRoot(rootOrSelector))
     },
 

diff --git a/src/lib/normalizeRoot.ts b/src/lib/normalizeRoot.ts
@@ -1,7 +1,7 @@
 import { isString } from './isString'
 import { isNil } from './isNil'
 
-export function normalizeRoot<R extends Element>(rootOrSelector: string | R): R {
+export function normalizeRoot<R extends Element>(rootOrSelector: string | R): R | never {
     if (isString(rootOrSelector)) {
         const rootOrNull = document.querySelector<R>(rootOrSelector)
 

diff --git a/src/types.ts b/src/types.ts
@@ -102,7 +102,7 @@ export interface AskRoot {
      * @typeParam K the HTML tag name literal type for the selector argument.
      *              This param is inferred from the selector argument.
      */
-    within<K extends keyof TagNameMap>(selector: K): AskEvent<TagNameMap[K], 'SINGLE'>
+    within<K extends keyof TagNameMap>(selector: K): AskEvent<TagNameMap[K], 'SINGLE'> | never
 
     /**
      * Start building an event-delegation handler for a specified root.
@@ -127,7 +127,7 @@ export interface AskRoot {
      * @typeParam R The element type for the root element.
      *              This param can be explicitly given to override the default `Element` type.
      */
-    within<R extends Element>(root: string): AskEvent<R, 'SINGLE'>
+    within<R extends Element>(root: string): AskEvent<R, 'SINGLE'> | never
 
     // ------------------------------------------------------------------------------
     //      EventDelegation.withinMany()