Improve type inference.

Type inferences for some kind of values(functions, records, promises,.etc) are not correct when deep option is enabled. It is because CamelCaseKeys type accepts Record<string, any> and then accepts some object-like types such as functions or promises.
sindresorhus · Jun 21, 2022 · 90fb08d · 90fb08d
1 parent e783aeb
commit 90fb08d
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Showing 3 changed files with 121 additions and 93 deletions.
diff --git a/index.d.ts b/index.d.ts
@@ -45,13 +45,15 @@ export type CamelCaseKeys<
 > = T extends readonly any[]
 	// Handle arrays or tuples.
 	? {
-		[P in keyof T]: CamelCaseKeys<
-		T[P],
-		Deep,
-		IsPascalCase,
-		Exclude,
-		StopPaths
-		>;
+		[P in keyof T]: Record<string, unknown> extends CamelCaseKeys<T[P]>
+			? T[P]
+			: CamelCaseKeys<
+			T[P],
+			Deep,
+			IsPascalCase,
+			Exclude,
+			StopPaths
+			>;
 	}
 	: T extends Record<string, any>
 		// Handle objects.
@@ -64,16 +66,18 @@ export type CamelCaseKeys<
 				true,
 			]
 				? T[P]
-				: [Deep] extends [true]
-					? CamelCaseKeys<
-					T[P],
-					Deep,
-					IsPascalCase,
-					Exclude,
-					StopPaths,
-					AppendPath<Path, P & string>
-					>
-					: T[P];
+				: Record<string, unknown> extends CamelCaseKeys<T[P]>
+					? T[P]
+					: [Deep] extends [true]
+						? CamelCaseKeys<
+						T[P],
+						Deep,
+						IsPascalCase,
+						Exclude,
+						StopPaths,
+						AppendPath<Path, P & string>
+						>
+						: T[P];
 		}
 		// Return anything else as-is.
 		: T;

diff --git a/index.test-d.ts b/index.test-d.ts
@@ -350,3 +350,27 @@ expectNotType<InvalidConvertedExcludeObjectDataType>(
 		exclude,
 	}),
 );
+
+expectType<{
+	funcFoo: () => 'foo';
+	recordBar: Record<string, unknown>;
+	promiseBaz: Promise<unknown>;
+}>(camelcaseKeys({
+			func_foo: () => 'foo',
+			record_bar: {foo: 'bar'},
+			promise_baz: new Promise(resolve => {
+				resolve(true);
+			}),
+		}));
+
+expectType<[
+	() => 'foo',
+	Record<string, unknown>,
+	Promise<unknown>,
+]>(camelcaseKeys([
+			() => 'foo',
+			{foo: 'bar'},
+			new Promise(resolve => {
+				resolve(true);
+			}),
+		]));
diff --git a/package.json b/package.json
@@ -1,77 +1,77 @@
 {
-	"name": "camelcase-keys",
-	"version": "8.0.0",
-	"description": "Convert object keys to camel case",
-	"license": "MIT",
-	"repository": "sindresorhus/camelcase-keys",
-	"funding": "https://github.com/sponsors/sindresorhus",
-	"author": {
-		"name": "Sindre Sorhus",
-		"email": "sindresorhus@gmail.com",
-		"url": "https://sindresorhus.com"
-	},
-	"type": "module",
-	"exports": "./index.js",
-	"types": "./index.d.ts",
-	"engines": {
-		"node": ">=14.16"
-	},
-	"scripts": {
-		"test": "xo && ava && tsd",
-		"bench": "matcha bench/bench.js"
-	},
-	"files": [
-		"index.js",
-		"index.d.ts"
-	],
-	"keywords": [
-		"map",
-		"obj",
-		"object",
-		"key",
-		"keys",
-		"value",
-		"values",
-		"val",
-		"iterate",
-		"camelcase",
-		"camel-case",
-		"camel",
-		"case",
-		"dash",
-		"hyphen",
-		"dot",
-		"underscore",
-		"separator",
-		"string",
-		"text",
-		"convert",
-		"pascalcase",
-		"pascal-case",
-		"deep",
-		"recurse",
-		"recursive"
-	],
-	"dependencies": {
-		"camelcase": "^7.0.0",
-		"map-obj": "^4.3.0",
-		"quick-lru": "^6.1.1",
-		"type-fest": "^2.13.0"
-	},
-	"devDependencies": {
-		"ava": "^4.3.0",
-		"matcha": "^0.7.0",
-		"tsd": "^0.20.0",
-		"xo": "^0.49.0"
-	},
-	"xo": {
-		"overrides": [
-			{
-				"files": "bench/bench.js",
-				"rules": {
-					"import/no-unresolved": "off"
-				}
-			}
-		]
-	}
-}
+  "name": "camelcase-keys",
+  "version": "8.0.0",
+  "description": "Convert object keys to camel case",
+  "license": "MIT",
+  "repository": "sindresorhus/camelcase-keys",
+  "funding": "https://github.com/sponsors/sindresorhus",
+  "author": {
+    "name": "Sindre Sorhus",
+    "email": "sindresorhus@gmail.com",
+    "url": "https://sindresorhus.com"
+  },
+  "type": "module",
+  "exports": "./index.js",
+  "types": "./index.d.ts",
+  "engines": {
+    "node": ">=14.16"
+  },
+  "scripts": {
+    "test": "xo && ava && tsd",
+    "bench": "matcha bench/bench.js"
+  },
+  "files": [
+    "index.js",
+    "index.d.ts"
+  ],
+  "keywords": [
+    "map",
+    "obj",
+    "object",
+    "key",
+    "keys",
+    "value",
+    "values",
+    "val",
+    "iterate",
+    "camelcase",
+    "camel-case",
+    "camel",
+    "case",
+    "dash",
+    "hyphen",
+    "dot",
+    "underscore",
+    "separator",
+    "string",
+    "text",
+    "convert",
+    "pascalcase",
+    "pascal-case",
+    "deep",
+    "recurse",
+    "recursive"
+  ],
+  "dependencies": {
+    "camelcase": "^7.0.0",
+    "map-obj": "^4.3.0",
+    "quick-lru": "^6.1.1",
+    "type-fest": "^2.13.0"
+  },
+  "devDependencies": {
+    "ava": "^4.3.0",
+    "matcha": "^0.7.0",
+    "tsd": "^0.20.0",
+    "xo": "^0.49.0"
+  },
+  "xo": {
+    "overrides": [
+      {
+        "files": "bench/bench.js",
+        "rules": {
+          "import/no-unresolved": "off"
+        }
+      }
+    ]
+  }
+}