feat: add TS declaration file

Closes #243

.github/workflows/nodejs.yml

@@ -26,3 +26,4 @@ jobs:
     - run: npm ls
     - run: npm test
     - run: npm run lint
+    - run: npm run type-coverage

.gitignore

@@ -2,3 +2,4 @@
 coverage
 node_modules
 *.log
+*.d.ts

LICENSE.txt

@@ -1,4 +1,4 @@
-Copyright 2013–2023 Kenan Yildirim <https://kenany.me/>
+Copyright 2013–2024 Kenan Yildirim <https://kenany.me/>
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of
 this software and associated documentation files (the "Software"), to deal in

index.js

@@ -5,6 +5,13 @@ const isEmpty = require('lodash.isempty');
 const isPlainObject = require('lodash.isplainobject');
 const strftime = require('strftime');
 
+/**
+ * @typedef {object} Options
+ * @property {number} [indent] Number of spaces for indentation.
+ * @property {boolean} [newlineAfterSection] Whether or not to output a newline
+ *   after the last pair in a hash if that hash wasn't empty.
+ */
+
 /**
  * @param {unknown} obj
  * @returns {string}
@@ -16,7 +23,7 @@ function format(obj) {
 }
 
 /**
- * @param {readonly unknown[][]} simplePairs
+ * @param {readonly [string, unknown][]} simplePairs
  * @returns {boolean}
  */
 function isArrayOfTables(simplePairs) {
@@ -55,7 +62,7 @@ function escapeKey(key) {
 
 /**
  * @param {object} hash
- * @param {object} options
+ * @param {Options} options
  * @returns {string}
  */
 module.exports = function(hash, options = {}) {
@@ -65,11 +72,15 @@ module.exports = function(hash, options = {}) {
    * @returns {void}
    */
   function visit(hash, prefix) {
+    /** @type {[string, object][]} */
     const nestedPairs = [];
+
+    /** @type {[string, unknown][]} */
     const simplePairs = [];
-    const indentStr = ''.padStart(options.indent, ' ');
+    const indentStr = ''.padStart(options.indent || 0, ' ');
 
     Object.keys(hash).forEach((key) => {
+      // @ts-expect-error
       const value = hash[key];
 
       if (value === undefined) {
@@ -106,6 +117,8 @@ module.exports = function(hash, options = {}) {
             toml += '\n';
           }
         }
+
+        // @ts-expect-error Asserted to be an array at this point.
         value.forEach((obj) => {
           if (!isEmpty(prefix)) {
             toml += '[[' + prefix + '.' + key + ']]\n';

package.json

@@ -10,7 +10,10 @@
   "license": "MIT",
   "author": "Kenan Yildirim <[email protected]> (https://kenany.me/)",
   "main": "index.js",
+  "types": "index.d.ts",
   "files": [
+    "CHANGELOG.md",
+    "index.d.ts",
     "index.js",
     "LICENSE.txt"
   ],
@@ -21,9 +24,15 @@
     "node": "18 || >=20"
   },
   "scripts": {
+    "clean": "rimraf --glob test/**/*.d.ts *.d.ts",
     "lint": "eslint .",
     "release": "semantic-release",
-    "test": "nyc --reporter html --reporter text tape test/*.js"
+    "type-coverage": "type-coverage --at-least 96 --detail --strict",
+    "prebuild": "npm run clean",
+    "build": "tsc",
+    "pretest": "npm run build",
+    "test": "nyc --reporter html --reporter text tape test/*.js",
+    "prepack": "npm run build"
   },
   "dependencies": {
     "lodash.isdate": "^4.0.1",
@@ -35,10 +44,19 @@
     "@kenan/eslint-config": "^11.1.3",
     "@semantic-release/changelog": "^6.0.3",
     "@semantic-release/git": "^10.0.1",
+    "@tsconfig/node18": "^18.2.2",
+    "@types/lodash.isdate": "^4.0.9",
+    "@types/lodash.isempty": "^4.4.9",
+    "@types/lodash.isplainobject": "^4.0.9",
+    "@types/strftime": "^0.9.8",
+    "@types/tape": "^5.6.4",
     "conventional-changelog-conventionalcommits": "^7.0.2",
     "eslint": "^8.56.0",
     "nyc": "^15.1.0",
+    "rimraf": "^5.0.5",
     "semantic-release": "^23.0.2",
-    "tape": "^5.7.5"
+    "tape": "^5.7.5",
+    "type-coverage": "^2.27.1",
+    "typescript": "^5.3.3"
   }
 }

tsconfig.json

@@ -0,0 +1,10 @@
+{
+  "extends": "@tsconfig/node18/tsconfig.json",
+  "compilerOptions": {
+    "allowJs": true,
+    "checkJs": true,
+    "declaration": true,
+    "emitDeclarationOnly": true
+  },
+  "include": ["index.js"]
+}