add types

index.d.ts

@@ -0,0 +1,17 @@
+type TypedArray =
+	| Int8Array
+	| Uint8Array
+	| Uint8ClampedArray
+	| Int16Array
+	| Uint16Array
+	| Int32Array
+	| Uint32Array
+	| Float32Array
+	| Float64Array
+	| BigInt64Array
+	| BigUint64Array;
+
+declare function typedArrayByteOffset(value: TypedArray): number;
+declare function typedArrayByteOffset(value: unknown): false;
+
+export = typedArrayByteOffset;

index.js

@@ -5,22 +5,30 @@ var callBind = require('call-bind');
 
 var typedArrays = require('available-typed-arrays')();
 
+/** @typedef {Int8Array | Uint8Array | Uint8ClampedArray | Int16Array | Uint16Array | Int32Array | Uint32Array | Float32Array | Float64Array | BigInt64Array | BigUint64Array} TypedArray */
+/** @typedef {(x: TypedArray) => number} ByteOffsetGetter */
+
+/** @type {Object.<typeof typedArrays, ByteOffsetGetter>} */
 var getters = {};
 var hasProto = require('has-proto')();
 
 var gOPD = require('gopd');
 var oDP = Object.defineProperty;
 if (gOPD) {
+	/** @type {ByteOffsetGetter} */
 	var getByteOffset = function (x) {
 		return x.byteOffset;
 	};
 	forEach(typedArrays, function (typedArray) {
 		// In Safari 7, Typed Array constructors are typeof object
 		if (typeof global[typedArray] === 'function' || typeof global[typedArray] === 'object') {
 			var Proto = global[typedArray].prototype;
+			// @ts-expect-error TS can't guarantee the callback is invoked sync
 			var descriptor = gOPD(Proto, 'byteOffset');
 			if (!descriptor && hasProto) {
+				// @ts-expect-error hush, TS, every object has a dunder proto
 				var superProto = Proto.__proto__; // eslint-disable-line no-proto
+				// @ts-expect-error TS can't guarantee the callback is invoked sync
 				descriptor = gOPD(superProto, 'byteOffset');
 			}
 			// Opera 12.16 has a magic byteOffset data property on instances AND on Proto
@@ -29,6 +37,7 @@ if (gOPD) {
 			} else if (oDP) {
 				// this is likely an engine where instances have a magic byteOffset data property
 				var arr = new global[typedArray](2);
+				// @ts-expect-error TS can't guarantee the callback is invoked sync
 				descriptor = gOPD(arr, 'byteOffset');
 				if (descriptor && descriptor.configurable) {
 					oDP(arr, 'length', { value: 3 });
@@ -41,9 +50,10 @@ if (gOPD) {
 	});
 }
 
+/** @type {ByteOffsetGetter} */
 var tryTypedArrays = function tryAllTypedArrays(value) {
-	var foundOffset;
-	forEach(getters, function (getter) {
+	/** @type {number} */ var foundOffset;
+	forEach(getters, /** @type {(getter: ByteOffsetGetter) => void} */ function (getter) {
 		if (typeof foundOffset !== 'number') {
 			try {
 				var offset = getter(value);
@@ -53,11 +63,13 @@ var tryTypedArrays = function tryAllTypedArrays(value) {
 			} catch (e) {}
 		}
 	});
+	// @ts-expect-error TS can't guarantee the callback is invoked sync
 	return foundOffset;
 };
 
 var isTypedArray = require('is-typed-array');
 
+/** @type {import('.')} */
 module.exports = function typedArrayByteOffset(value) {
 	if (!isTypedArray(value)) {
 		return false;

package.json

@@ -7,6 +7,7 @@
 		".": "./index.js",
 		"./package.json": "./package.json"
 	},
+	"types": "./index.d.ts",
 	"sideEffects": false,
 	"scripts": {
 		"prepack": "npmignore --auto --commentLines=autogenerated",
@@ -64,6 +65,14 @@
 	},
 	"devDependencies": {
 		"@ljharb/eslint-config": "^21.1.0",
+		"@types/call-bind": "^1.0.5",
+		"@types/for-each": "^0.3.3",
+		"@types/gopd": "^1.0.3",
+		"@types/is-callable": "^1.1.2",
+		"@types/make-arrow-function": "^1.2.2",
+		"@types/make-generator-function": "^2.0.3",
+		"@types/object-inspect": "^1.8.4",
+		"@types/tape": "^5.6.4",
 		"aud": "^2.0.4",
 		"auto-changelog": "^2.4.0",
 		"eslint": "=8.8.0",
@@ -75,8 +84,10 @@
 		"npmignore": "^0.3.1",
 		"nyc": "^10.3.2",
 		"object-inspect": "^1.13.1",
+		"possible-typed-array-names": "^1.0.0",
 		"safe-publish-latest": "^2.0.0",
-		"tape": "^5.7.5"
+		"tape": "^5.7.5",
+		"typescript": "^5.4.0-dev.20240219"
 	},
 	"engines": {
 		"node": ">= 0.4"

test/index.js

@@ -8,22 +8,11 @@ var arrowFn = require('make-arrow-function')();
 var forEach = require('for-each');
 var inspect = require('object-inspect');
 
-var typedArrayNames = [
-	'Int8Array',
-	'Uint8Array',
-	'Uint8ClampedArray',
-	'Int16Array',
-	'Uint16Array',
-	'Int32Array',
-	'Uint32Array',
-	'Float32Array',
-	'Float64Array',
-	'BigInt64Array',
-	'BigUint64Array'
-];
+var typedArrayNames = require('possible-typed-array-names');
 
 test('not arrays', function (t) {
 	t.test('non-number/string primitives', function (st) {
+		// @ts-expect-error
 		st.equal(false, typedArrayByteOffset(), 'undefined is not typed array');
 		st.equal(false, typedArrayByteOffset(null), 'null is not typed array');
 		st.equal(false, typedArrayByteOffset(false), 'false is not typed array');

tsconfig.json

@@ -0,0 +1,49 @@
+{
+  "compilerOptions": {
+    /* Visit https://aka.ms/tsconfig to read more about this file */
+
+    /* Projects */
+
+    /* Language and Environment */
+    "target": "ESNext",                                  /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
+    // "lib": [],                                        /* Specify a set of bundled library declaration files that describe the target runtime environment. */
+    // "noLib": true,                                    /* Disable including any library files, including the default lib.d.ts. */
+    "useDefineForClassFields": true,                     /* Emit ECMAScript-standard-compliant class fields. */
+    // "moduleDetection": "auto",                        /* Control what method is used to detect module-format JS files. */
+
+    /* Modules */
+    "module": "commonjs",                                /* Specify what module code is generated. */
+    // "rootDir": "./",                                  /* Specify the root folder within your source files. */
+    // "moduleResolution": "node10",                     /* Specify how TypeScript looks up a file from a given module specifier. */
+    // "baseUrl": "./",                                  /* Specify the base directory to resolve non-relative module names. */
+    // "paths": {},                                      /* Specify a set of entries that re-map imports to additional lookup locations. */
+    // "rootDirs": [],                                   /* Allow multiple folders to be treated as one when resolving modules. */
+    "typeRoots": ["types"],                              /* Specify multiple folders that act like './node_modules/@types'. */
+    "resolveJsonModule": true,                           /* Enable importing .json files. */
+    // "allowArbitraryExtensions": true,                 /* Enable importing files with any extension, provided a declaration file is present. */
+
+    /* JavaScript Support */
+    "allowJs": true,                                     /* Allow JavaScript files to be a part of your program. Use the 'checkJS' option to get errors from these files. */
+    "checkJs": true,                                     /* Enable error reporting in type-checked JavaScript files. */
+    "maxNodeModuleJsDepth": 0,                           /* Specify the maximum folder depth used for checking JavaScript files from 'node_modules'. Only applicable with 'allowJs'. */
+
+    /* Emit */
+    "declaration": true,                                 /* Generate .d.ts files from TypeScript and JavaScript files in your project. */
+    "declarationMap": true,                              /* Create sourcemaps for d.ts files. */
+    "noEmit": true,                                      /* Disable emitting files from a compilation. */
+
+    /* Interop Constraints */
+    "allowSyntheticDefaultImports": true,                /* Allow 'import x from y' when a module doesn't have a default export. */
+    "esModuleInterop": true,                             /* Emit additional JavaScript to ease support for importing CommonJS modules. This enables 'allowSyntheticDefaultImports' for type compatibility. */
+    "forceConsistentCasingInFileNames": true,            /* Ensure that casing is correct in imports. */
+
+    /* Type Checking */
+    "strict": true,                                      /* Enable all strict type-checking options. */
+
+    /* Completeness */
+    //"skipLibCheck": true                                 /* Skip type checking all .d.ts files. */
+  },
+  "exclude": [
+    "coverage"
+  ]
+}