feat: convert to typescript & export a binary

.gitignore

@@ -1,2 +1,3 @@
 node_modules
+lib
 *.log

package.json

@@ -2,17 +2,30 @@
   "name": "qr-decode-encode",
   "description": "Shell scripts for decoding / encoding QR codes.",
   "version": "0.0.0-unversioned",
-  "main": "decode.js",
+  "main": "lib/index.js",
+  "bin": "lib/bin.js",
   "scripts": {
-    "decode": "node decode.js",
-    "encode": "node encode.js",
-    "test": "[ \"$(node decode.js \"$(node encode.js 'magic_test_string')\")\" == \"magic_test_string\" ]"
+    "start": "ts-node src/bin.ts",
+    "build": "tsc && chmod +x lib/bin.js",
+    "clean": "rimraf lib",
+    "test": "[ \"$(ts-node src/bin.ts decode \"$(ts-node src/bin.ts encode 'magic_test_string')\")\" == \"magic_test_string\" ]",
+    "type-check": "tsc --noEmit",
+    "decode": "yarn start decode",
+    "encode": "yarn start encode"
   },
   "license": "MIT",
   "author": "Matt Lubner <matt@mattlubner.com>",
   "dependencies": {
     "jimp": "^0.14.0",
     "jsqr": "^1.3.1",
-    "qrcode": "^1.4.4"
+    "qrcode": "^1.4.4",
+    "ts-node": "^9.0.0",
+    "typescript": "^4.0.5",
+    "yargs": "^16.1.0"
+  },
+  "devDependencies": {
+    "@types/qrcode": "^1.3.5",
+    "@types/yargs": "^15.0.9",
+    "rimraf": "^3.0.2"
   }
 }

src/atoqr.ts

@@ -0,0 +1,11 @@
+import * as QRCode from 'qrcode';
+
+/**
+ * Encodes an ascii string into a data URL-embedded QR code.
+ */
+export const atoqr = async (ascii: string, output: 'dataUrl' | string = 'dataUrl'): Promise<string> => {
+  if (output === 'dataUrl') {
+    return QRCode.toDataURL(ascii);
+  }
+  return QRCode.toFile(output, ascii);
+};

src/bin.ts

@@ -0,0 +1,69 @@
+#!/usr/bin/env node
+import yargs from 'yargs';
+import { readFileSync } from 'fs';
+import { normalize } from 'path';
+import { atoqr, qrtoa } from './';
+
+const argv = yargs(process.argv.slice(2))
+  .scriptName(require('../package.json').name)
+  .usage('Usage: $0 <command> [options]')
+  .command('decode <qr_code>', 'Decode qr_code back into an ascii string', _yargs => {
+    _yargs.positional('qr_code', {
+      describe: 'A data url or a path to an image file',
+      type: 'string',
+    });
+  })
+  .alias('qrtoa', 'decode')
+  .command('encode <ascii> [options]', 'Encode an ascii string into a qr code', _yargs => {
+    _yargs.positional('ascii', {
+      describe: 'An ascii string',
+    }).option('file', {
+      alias: 'f',
+      describe: 'Path to save output to (as *.{png,svg,txt})',
+      normalize: true,
+      type: 'string',
+    });
+  })
+  .alias('atoqr', 'encode')
+  .demandCommand(1, 'You must specify a command')
+  .option('clean', {
+    alias: 'c',
+    describe: 'Omit the trailing newline',
+    type: 'boolean',
+  })
+  .help('h')
+  .alias('h', 'help')
+  .argv;
+
+const [command] = argv._;
+
+const main = async () => {
+  switch (command) {
+    case 'decode': {
+      const dataUrlOrFile = argv.qr_code as string;
+      const [, content] = dataUrlOrFile.match(/^data:image\/(?:jpeg|png|bmp|tiff|gif);base64,(.+)$/) || [];
+      const isDataUrl = !!content;
+      const buffer = isDataUrl
+        ? Buffer.from(content, 'base64')
+        : readFileSync(normalize(dataUrlOrFile));
+      const ascii = await qrtoa(buffer);
+      process.stdout.write(ascii);
+      break;
+    }
+    case 'encode': {
+      const ascii = argv.ascii as string;
+      const file = argv.file as string | undefined;
+      const qrCode = await atoqr(ascii, file);
+      process.stdout.write(qrCode);
+      break;
+    }
+  }
+  if (!argv.clean) {
+    process.stdout.write('\n');
+  }
+};
+
+main().catch(err => {
+  console.error(err);
+  process.exit(1);
+});

src/index.ts

@@ -0,0 +1,2 @@
+export * from './atoqr';
+export * from './qrtoa';

src/qrtoa.ts

@@ -0,0 +1,14 @@
+import Jimp from 'jimp';
+import jsQR from 'jsqr';
+
+/**
+ * Decodes a buffer containing a QR code into an ascii string.
+ */
+export const qrtoa = async (buffer: Buffer): Promise<string> => {
+  const image = await Jimp.read(buffer);
+  const result = jsQR(new Uint8ClampedArray(image.bitmap.data), image.bitmap.width, image.bitmap.height);
+  if (!result) {
+    return Promise.reject(new Error('Failed to parse qr_code'));
+  }
+  return result.data;
+};

tsconfig.json

@@ -0,0 +1,24 @@
+{
+  "compilerOptions": {
+    "allowJs": true,
+    "esModuleInterop": true,
+    "forceConsistentCasingInFileNames": true,
+    "lib": [
+      "es6"
+    ],
+    "moduleResolution": "node",
+    "outDir": "lib",
+    "resolveJsonModule": true,
+    "rootDir": "src",
+    "skipLibCheck": true,
+    "strict": true,
+    "target": "es5"
+  },
+  "include": [
+    "src/*.ts"
+  ],
+  "exclude": [
+    "node_modules",
+    "package.json"
+  ]
+}