Add Typescript for type checking (but still with js files)

.eslintrc.json

@@ -3,7 +3,8 @@
     "es2021": true,
     "node": true
   },
-  "extends": "standard",
+  "extends": ["eslint:recommended", "plugin:@typescript-eslint/recommended"],
+  "parser": "@typescript-eslint/parser",
   "parserOptions": {
     "ecmaVersion": "latest",
     "sourceType": "module"

.gitignore

@@ -1,3 +1,4 @@
 /node_modules
+lib
 npm-debug.log
 .DS_Store

package.json

@@ -17,14 +17,24 @@
   "engines": {
     "node": ">=18"
   },
+  "files": [
+    "lib",
+    "test",
+    "*.json",
+    "*.md",
+    "license.txt"
+  ],
   "scripts": {
-    "lint": "eslint lib/*.js test/*.js index.js",
+    "start": "tsc --watch",
+    "build": "tsc",
+    "lint": "eslint src/*.js test/*.js",
     "test-generate-mo": "msgfmt test/fixtures/latin13.po -o test/fixtures/latin13.mo & msgfmt test/fixtures/utf8.po -o test/fixtures/utf8.mo & msgfmt test/fixtures/obsolete.po -o test/fixtures/obsolete.mo",
     "test": "mocha",
     "preversion": "npm run lint && npm test",
     "postversion": "git push && git push --tags"
   },
-  "main": "./index.js",
+  "main": "./lib/index.js",
+  "types": "./lib/index.d.ts",
   "license": "MIT",
   "dependencies": {
     "content-type": "^1.0.5",
@@ -33,13 +43,19 @@
     "safe-buffer": "^5.2.1"
   },
   "devDependencies": {
-    "chai": "^5.0.3",
+    "@types/chai": "latest",
+    "@types/content-type": "^1.1.8",
+    "@types/mocha": "latest",
+    "@typescript-eslint/eslint-plugin": "^6.18.1",
+    "@typescript-eslint/parser": "^6.14.0",
+    "chai": "^5.1.0",
     "eslint": "^8.56.0",
     "eslint-config-standard": "^17.1.0",
     "eslint-plugin-import": "^2.29.1",
     "eslint-plugin-n": "^16.6.2",
     "eslint-plugin-promise": "^6.1.1",
-    "mocha": "^10.3.0"
+    "mocha": "^10.4.0",
+    "typescript": "^5.4.4"
   },
   "keywords": [
     "i18n",

src/index.d.ts

@@ -0,0 +1,49 @@
+import { Transform } from "readable-stream";
+import {Buffer} from "safe-buffer";
+
+export declare module 'encoding' {
+    export function convert(buf: Buffer, charset: string): Buffer;
+}
+
+export interface Compiler {
+    _table: GetTextTranslations;
+    compile(): Buffer;
+}
+
+export interface GetTextComment {
+    translator?: string;
+    reference?: string;
+    extracted?: string;
+    flag?: string;
+    previous?: string;
+}
+
+export interface GetTextTranslation {
+    msgctxt?: string;
+    msgid: string;
+    msgid_plural?: string[];
+    msgstr: string[];
+    comments?: GetTextComment;
+}
+
+export interface GetTextTranslations {
+    charset: string;
+    headers: { [headerName: string]: string };
+    translations: { [msgctxt: string]: { [msgId: string]: GetTextTranslation } };
+}
+
+export interface parserOptions {
+    defaultCharset?: string;
+    validation?: boolean;
+}
+
+export interface PoParser {
+    parse: (buffer: Buffer | string, defaultCharset?: string) => GetTextTranslations;
+    compile: (table: GetTextTranslations, options?: parserOptions) => Buffer;
+    createParseStream: (options?: parserOptions, transformOptions?: import('readable-stream').TransformOptions) => Transform;
+}
+
+export interface MoParser {
+    parse: (buffer: Buffer | string, defaultCharset?: string) => GetTextTranslations;
+    compile: (table: GetTextTranslations, options?: parserOptions) => Buffer;
+}

src/index.js

@@ -0,0 +1,27 @@
+import * as poParser from './poparser.js';
+import poCompiler from './pocompiler.js';
+import moParser from './moparser.js';
+import moCompiler from './mocompiler.js';
+
+/**
+ * Translation parser and compiler for PO files
+ * @see https://www.gnu.org/software/gettext/manual/html_node/PO.html
+ *
+ * @type {import("./index.js").PoParser} po
+ */
+export const po = {
+  parse: poParser.parse,
+  createParseStream: poParser.stream,
+  compile: poCompiler
+};
+
+/**
+ * Translation parser and compiler for PO files
+ * @see https://www.gnu.org/software/gettext/manual/html_node/MO.html
+ *
+ * @type {import("./index.js").MoParser} mo
+ */
+export const mo= {
+  parse: moParser,
+  compile: moCompiler
+};

lib/mocompiler.js → src/mocompiler.js

@@ -1,28 +1,29 @@
 import { Buffer } from 'safe-buffer';
 import encoding from 'encoding';
-import { HEADERS, formatCharset, generateHeader, compareMsgid } from './shared.js';
+import { compareMsgid, formatCharset, generateHeader, HEADERS } from './shared.js';
 import contentType from 'content-type';
 
 /**
  * Exposes general compiler function. Takes a translation
  * object as a parameter and returns binary MO object
  *
- * @param {Object} table Translation object
+ * @param {import('./index.js').gettextTranslations} table Translation object
  * @return {Buffer} Compiled binary MO object
  */
 export default function (table) {
   const compiler = new Compiler(table);
 
   return compiler.compile();
-};
+}
 
 /**
  * Creates a MO compiler object.
  *
  * @constructor
- * @param {Object} table Translation table as defined in the README
+ * @param {import('./index.js').gettextTranslations} table Translation table as defined in the README
+ * @return {import('./index.js').Compiler} Compiler
  */
-function Compiler (table = {}) {
+function Compiler (table ) {
   this._table = table;
 
   let { headers = {}, translations = {} } = this._table;
@@ -70,6 +71,8 @@ function Compiler (table = {}) {
   this._writeFunc = 'writeUInt32LE';
 
   this._handleCharset();
+
+  return this;
 }
 
 /**
@@ -148,7 +151,7 @@ Compiler.prototype._generateList = function () {
 /**
  * Calculate buffer size for the final binary object
  *
- * @param {Array} list An array of translation strings from _generateList
+ * @param {import('./index.js').GettextTranslations} list An array of translation strings from _generateList
  * @return {Object} Size data of {msgid, msgstr, total}
  */
 Compiler.prototype._calculateSize = function (list) {
@@ -183,7 +186,7 @@ Compiler.prototype._calculateSize = function (list) {
 /**
  * Generates the binary MO object from the translation list
  *
- * @param {Array} list translation list
+ * @param {import('./index.js').GettextTranslations} list translation list
  * @param {Object} size Byte size information
  * @return {Buffer} Compiled MO object
  */
@@ -237,7 +240,7 @@ Compiler.prototype._build = function (list, size) {
 };
 
 /**
- * Compiles translation object into a binary MO object
+ * Compiles the translation object into a binary MO object
  *
  * @return {Buffer} Compiled MO object
  */

lib/moparser.js → src/moparser.js

@@ -12,7 +12,7 @@ export default function (buffer, defaultCharset) {
   const parser = new Parser(buffer, defaultCharset);
 
   return parser.parse();
-};
+}
 
 /**
  * Creates a MO parser object.
@@ -135,7 +135,7 @@ Parser.prototype._handleCharset = function (headers) {
  * Adds a translation to the translation object
  *
  * @param {String} msgid Original string
- * @params {String} msgstr Translation for the original string
+ * @param {String} msgstr Translation for the original string
  */
 Parser.prototype._addString = function (msgid, msgstr) {
   const translation = {};

lib/pocompiler.js → src/pocompiler.js

@@ -1,20 +1,20 @@
-import { Buffer } from 'safe-buffer';
-import encoding from 'encoding';
-import { HEADERS, foldLine, compareMsgid, formatCharset, generateHeader } from './shared.js';
+import { compareMsgid, foldLine, formatCharset, generateHeader, HEADERS } from './shared.js';
 import contentType from 'content-type';
+import encoding from 'encoding';
 
 /**
  * Exposes general compiler function. Takes a translation
  * object as a parameter and returns PO object
  *
  * @param {Object} table Translation object
+ * @param options
  * @return {Buffer} Compiled PO object
  */
 export default function (table, options) {
   const compiler = new Compiler(table, options);
 
   return compiler.compile();
-};
+}
 
 /**
  * Creates a PO compiler object.
@@ -72,7 +72,7 @@ function Compiler (table = {}, options = {}) {
  * @param {Object} comments A comments object
  * @return {String} A comment string for the PO file
  */
-Compiler.prototype._drawComments = function (comments) {
+Compiler.prototype._drawComments = function (comments){
   const lines = [];
   const types = [{
     key: 'translator',

lib/poparser.js → src/poparser.js

@@ -1,5 +1,5 @@
 import encoding from 'encoding';
-import { formatCharset, parseNPluralFromHeadersSafely, parseHeader } from './shared.js';
+import { formatCharset, parseHeader, parseNPluralFromHeadersSafely } from './shared.js';
 import { Transform } from 'readable-stream';
 import util from 'util';
 
@@ -14,18 +14,18 @@ export function parse (input, options = {}) {
   const parser = new Parser(input, options);
 
   return parser.parse();
-};
+}
 
 /**
  * Parses a PO stream, emits translation table in object mode
  *
- * @typedef {{ defaultCharset: strubg, validation: boolean }} Options
+ * @typedef {{ defaultCharset: string, validation: boolean }} Options
  * @param {Options} [options] Optional options with defaultCharset and validation
  * @param {import('readable-stream').TransformOptions} [transformOptions] Optional stream options
  */
 export function stream (options = {}, transformOptions = {}) {
   return new PoParserTransform(options, transformOptions);
-};
+}
 
 /**
  * Creates a PO parser object. If PO object is a string,
@@ -68,7 +68,7 @@ Parser.prototype.parse = function () {
 /**
  * Detects charset for PO strings from the header
  *
- * @param {Buffer} headers Header value
+ * @param buf PO string buffer to be parsed
  */
 Parser.prototype._handleCharset = function (buf = '') {
   const str = buf.toString();
@@ -77,8 +77,8 @@ Parser.prototype._handleCharset = function (buf = '') {
   let match;
 
   if ((pos = str.search(/^\s*msgid/im)) >= 0) {
-    pos = pos + str.substr(pos + 5).search(/^\s*(msgid|msgctxt)/im);
-    headers = str.substr(0, pos >= 0 ? pos + 5 : str.length);
+    pos = pos + str.substring(pos + 5).search(/^\s*(msgid|msgctxt)/im);
+    headers = str.substring(0, pos >= 0 ? pos + 5 : str.length);
   }
 
   if ((match = headers.match(/[; ]charset\s*=\s*([\w-]+)(?:[\s;]|\\n)*"\s*$/mi))) {
@@ -515,7 +515,7 @@ Parser.prototype._finalize = function (tokens) {
 /**
  * Creates a transform stream for parsing PO input
  *
- * @typedef {{ defaultCharset: strubg, validation: boolean }} Options
+ * @typedef {{ defaultCharset: string, validation: boolean }} Options
  * @constructor
  * @param {Options} options Optional options with defaultCharset and validation
  * @param {import('readable-stream').TransformOptions} transformOptions Optional stream options
@@ -533,6 +533,8 @@ function PoParserTransform (options, transformOptions) {
   Transform.call(this, transformOptions);
   this._writableState.objectMode = false;
   this._readableState.objectMode = true;
+
+  return this;
 }
 util.inherits(PoParserTransform, Transform);
 

lib/shared.js → src/shared.js

@@ -1,5 +1,7 @@
 // see https://www.gnu.org/software/gettext/manual/html_node/Header-Entry.html
+
 const PLURAL_FORMS = 'Plural-Forms';
+
 export const HEADERS = new Map([
   ['project-id-version', 'Project-Id-Version'],
   ['report-msgid-bugs-to', 'Report-Msgid-Bugs-To'],
@@ -43,10 +45,11 @@ export function parseHeader (str = '') {
  * Attempts to safely parse 'nplurals" value from "Plural-Forms" header
  *
  * @param {Object} [headers = {}] An object with parsed headers
+ * @param fallback {Number} Fallback value
  * @returns {number} Parsed result
  */
-export function parseNPluralFromHeadersSafely (headers = {}, fallback = 1) {
-  const pluralForms = headers[PLURAL_FORMS];
+export function parseNPluralFromHeadersSafely (headers, fallback = 1) {
+  const pluralForms = headers ? headers[PLURAL_FORMS] : false;
 
   if (!pluralForms) {
     return fallback;
@@ -83,6 +86,7 @@ export function generateHeader (header = {}) {
  * Normalizes charset name. Converts utf8 to utf-8, WIN1257 to windows-1257 etc.
  *
  * @param {String} charset Charset name
+ * @param defaultCharset Default charset (default: 'iso-8859-1')
  * @return {String} Normalized charset name
  */
 export function formatCharset (charset = 'iso-8859-1', defaultCharset = 'iso-8859-1') {
@@ -101,7 +105,7 @@ export function formatCharset (charset = 'iso-8859-1', defaultCharset = 'iso-885
  *
  * @param {String} str PO formatted string to be folded
  * @param {Number} [maxLen=76] Maximum allowed length for folded lines
- * @return {Array} An array of lines
+ * @return {string[]} An array of lines
  */
 export function foldLine (str, maxLen = 76) {
   const lines = [];

test/mo-compiler-test.js

@@ -1,7 +1,7 @@
 import * as chai from 'chai';
 import { promisify } from 'util';
 import path from 'path';
-import { mo } from '../index.js';
+import { mo } from '../src/index.js';
 import { readFile as fsReadFile } from 'fs';
 import { fileURLToPath } from 'url';