fix: add typing to allow for non-objects input args (#42)

.github/workflows/ci.yml

@@ -21,5 +21,6 @@ jobs:
       - run: pnpm install
       - run: pnpm lint
       - run: pnpm build
+      - run: pnpm test:types
       - run: pnpm vitest --coverage
       - uses: codecov/codecov-action@v2

package.json

@@ -22,7 +22,8 @@
     "lint": "eslint --ext .ts src",
     "prepack": "pnpm build",
     "release": "pnpm test && standard-version && git push --follow-tags && pnpm publish",
-    "test": "pnpm lint && pnpm vitest"
+    "test": "pnpm lint && pnpm vitest",
+    "test:types": "tsc --noEmit"
   },
   "devDependencies": {
     "@nuxtjs/eslint-config-typescript": "latest",

src/types.ts

@@ -1,11 +1,12 @@
 type Input = Record<string | number | symbol, any>
+type IgnoredInput = boolean | number | null | any[] | undefined
 
 export type Merger = <T extends Input, K extends keyof T>(
   obj: T,
   key: keyof T,
   value: T[K],
   namespace: string
-) => any;
+) => any
 
 type nullish = null | undefined | void
 
@@ -27,16 +28,16 @@ type MergeObjects<
 export type DefuFn = <Source extends Input, Defaults extends Input>(
   source: Source,
   ...defaults: Defaults[]
-) => MergeObjects<Source, Defaults>;
+) => MergeObjects<Source, Defaults>
 
 export interface Defu {
-  <Source extends Input, Defaults extends Input>(source: Source, ...defaults: Defaults[]): MergeObjects<
+  <Source extends Input, Defaults extends Input>(source: Source | IgnoredInput, ...defaults: Array<Defaults | IgnoredInput>): MergeObjects<
     Source,
     Defaults
-  >;
-  fn: DefuFn;
-  arrayFn: DefuFn;
-  extend(merger?: Merger): DefuFn;
+  >
+  fn: DefuFn
+  arrayFn: DefuFn
+  extend(merger?: Merger): DefuFn
 }
 
 type MergeArrays<Destination, Source> = Destination extends Array<infer DestinationType>

test/defu.test.ts

@@ -58,14 +58,12 @@ describe('defu', () => {
 
   it('should handle non object first param', () => {
     for (const val of nonObject) {
-      // @ts-expect-error
       expect(defu(val, { d: true })).toEqual({ d: true })
     }
   })
 
   it('should handle non object second param', () => {
     for (const val of nonObject) {
-      // @ts-expect-error
       expect(defu({ d: true }, val)).toEqual({ d: true })
     }
   })
@@ -92,7 +90,6 @@ describe('defu', () => {
   })
 
   it('should ignore non-object arguments', () => {
-    // @ts-expect-error
     expect(defu(null, { foo: 1 }, false, 123, { bar: 2 })).toEqual({
       foo: 1,
       bar: 2

tsconfig.json

@@ -2,9 +2,12 @@
   "compilerOptions": {
     "target": "ESNext",
     "module": "ESNext",
+    "moduleResolution": "node",
+    "skipLibCheck": true,
     "declaration": true
   },
   "include": [
-    "src"
+    "src",
+    "test"
   ]
 }