Refactored to typescript & more consistent code

Updated how we interface with figlet and unified error handling &
response.

.eslintrc.json

@@ -0,0 +1,31 @@
+{
+  "root": true,
+  "parserOptions": {
+    "parser": "@typescript-eslint/parser",
+    "ecmaVersion": 2020,
+    "sourceType": "module"
+  },
+  "extends": [
+    "eslint-config-airbnb-base",
+    "plugin:@typescript-eslint/recommended"
+  ],
+  "plugins": ["@typescript-eslint"],
+  "rules": {
+    "lines-between-class-members": [
+      "error",
+      "always",
+      { "exceptAfterSingleLine": true }
+    ],
+    "max-classes-per-file": 1,
+    "no-empty": [
+      2,
+      {
+        "allowEmptyCatch": true
+      }
+    ],
+    "no-promise-executor-return": 1,
+    "no-shadow": "off",
+    "no-underscore-dangle": "off",
+    "@typescript-eslint/no-var-requires": "off"
+  }
+}

.gitignore

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

package.json

@@ -1,9 +1,19 @@
 {
+  "version": "1.0.0",
   "scripts": {
-    "start": "node src/app.js"
+    "build": "tsc",
+    "start": "node lib/app.js"
   },
   "dependencies": {
+    "eslint": "^8.25.0",
+    "eslint-config-airbnb-base": "^15.0.0",
     "express": "^4.18.2",
-    "figlet": "^1.5.2"
+    "figlet": "^1.5.2",
+    "typescript": "^4.8.4"
+  },
+  "devDependencies": {
+    "@types/node": "^18.11.2",
+    "@typescript-eslint/eslint-plugin": "^5.40.1",
+    "@typescript-eslint/parser": "^5.40.1"
   }
 }

src/app.js

@@ -1,15 +0,0 @@
-const express = require("express");
-
-const asciiFontController = require("./controllers/asciiController.js");
-const modtFontController = require("./controllers/motdController.js");
-const requiredQueryMiddleware = require("./requiredQueryMiddleware");
-
-const app = express();
-const port = 3000;
-
-app.get("/ascii", requiredQueryMiddleware, asciiFontController);
-app.get("/motd", requiredQueryMiddleware, modtFontController);
-
-app.listen(port, () => {
-  console.log(`Font generation application listening on port ${port}.`);
-});

src/app.ts

@@ -0,0 +1,17 @@
+import express from "express";
+
+import figletontController from "./controllers/figletController";
+import modtFontController from "./controllers/motdController";
+import fontsController from "./controllers/fontsController";
+import requiredQueryMiddleware from "./requiredQueryMiddleware";
+
+const app = express();
+const port = 3000;
+
+app.get("/figlet", requiredQueryMiddleware, figletontController);
+app.get("/motd", requiredQueryMiddleware, modtFontController);
+app.get("/fonts", fontsController);
+
+app.listen(port, () => {
+  console.log(`Figlet generation application listening on port ${port}.`);
+});

src/ascii.js

@@ -1,33 +0,0 @@
-const figlet = require("figlet");
-
-const defaultFontOptions = {
-  font: "Larry 3D",
-  horizontalLayout: "default",
-  verticalLayout: "default",
-  width: 80,
-  whitespaceBreak: true,
-};
-
-function generateAscii(message, options) {
-  const _options = {
-    ...defaultFontOptions,
-    ...options,
-  };
-
-  return new Promise((resolve, reject) => {
-    figlet.text(message, _options, (err, data) => {
-      if (err) {
-        console.error("error from figlet:", error);
-        return reject(err);
-      }
-
-      if (_options.font === "Larry 3D") {
-        data = data.replaceAll("L", "_");
-      }
-
-      resolve(data);
-    });
-  });
-}
-
-module.exports = generateAscii;

src/controllers/asciiController.js

@@ -1,16 +0,0 @@
-const generateAscii = require("../ascii.js");
-
-const asciiFontController = (req, res) => {
-  const { text } = req.query;
-
-  return generateAscii(text)
-    .then((ascii) => res.send(ascii))
-    .catch((error) =>
-      res.status(error?.statusCode || 500).send({
-        success: false,
-        message: error?.message || "Unexpected error from font generation",
-      })
-    );
-};
-
-module.exports = asciiFontController;

src/controllers/figletController.ts

@@ -0,0 +1,20 @@
+import FigletFonts from "../figletFonts";
+import IFigletOptions from "../interfaces/IFigletOptions";
+
+const figletFonts = new FigletFonts();
+
+const figletTextController = async (req, res) => {
+  const { text, font, width } = req.query;
+  let options: IFigletOptions | Object = {};
+  if (font) options = { ...options, font };
+  if (width) options = { ...options, width };
+  
+  figletFonts.generateText(text, options as IFigletOptions)
+    .then(data => res.send(data))
+    .catch((error) => {
+      const msg = error?.message || "Unexpected error from generating figlet";
+      res.status(error?.statusCode || 500).send(msg)
+    });
+};
+
+export default figletTextController;

src/controllers/fontsController.ts

@@ -0,0 +1,14 @@
+import FigletFonts from "../figletFonts.js";
+
+const figletFonts = new FigletFonts();
+
+const fontsController = (req, res) => {
+  return figletFonts.fonts
+    .then((fonts) => res.send(fonts))
+    .catch((error) => {
+      const msg = error?.message || "Unexpected error from fetching fonts"
+      res.status(error?.statusCode || 500).send(msg)
+    });
+};
+
+export default fontsController;

src/controllers/motdController.js

@@ -1,17 +0,0 @@
-const generateAscii = require("../ascii.js");
-
-const modtFontController = (req, res) => {
-  const { text } = req.query;
-
-  return generateAscii(message)
-    .then((ascii) => generateCatOutput(ascii))
-    .then((motd) => res.send(motd))
-    .catch((error) => {
-      return res.status(500).send({
-        success: false,
-        message: "Unexpected error from font generation",
-      });
-    });
-};
-
-module.exports = modtFontController;

src/controllers/motdController.ts

@@ -0,0 +1,29 @@
+import FigletFonts from "../figletFonts";
+import IFigletOptions from "../interfaces/IFigletOptions";
+
+const figletFonts = new FigletFonts()
+
+function generateCatOutput(data: string) {
+  return Promise.resolve(`#!/bin/sh
+cat << 'EOF'
+${data}
+EOF
+  `)
+}
+
+const modtFontController = (req, res) => {
+  const { text, font, width } = req.query;
+  let options: IFigletOptions | Object = {};
+  if (font) options = { ...options, font };
+  if (width) options = { ...options, width };
+
+  figletFonts.generateText(text, options as IFigletOptions)
+    .then((data) => generateCatOutput(data))
+    .then((motd) => res.send(motd))
+    .catch((error) => {
+      const msg = error?.message || "Unexpected error from generating motd figlet"
+      res.status(error?.statusCode || 500).send(msg)
+    });
+};
+
+export default modtFontController;

src/errors.js

@@ -1,13 +0,0 @@
-class MissingTextError extends Error {
-  constructor(error = null) {
-    const message = `Missing query parameter 'text'`;
-    super(message);
-
-    this.error = error;
-    this.statusCode = 400;
-  }
-}
-
-module.exports = {
-  MissingTextError,
-};

src/errors.ts

@@ -0,0 +1,47 @@
+class MissingTextError extends Error {
+  error: string
+  statusCode: number
+
+  constructor(error = null) {
+    const message = `Missing query parameter 'text'.`;
+    super(message);
+
+    this.error = error;
+    this.statusCode = 400;
+  }
+}
+
+class FontNotFoundError extends Error {
+  error: string
+  statusCode: number
+
+  constructor(font, error = null) {
+    const message = `Font '${font}' not found. Check /fonts.`;
+    super(message);
+
+    this.error = error;
+    this.statusCode = 404;
+  }
+}
+
+class UnexpectedFigletError extends Error {
+  error: string
+  statusCode: number
+
+  constructor(error) {
+    const message = "Unexpected error from figlet!"
+    super(message)
+
+    this.error = error;
+    this.statusCode = 500
+
+    console.log(message)
+    console.log(error)
+  }
+}
+
+export {
+  MissingTextError,
+  FontNotFoundError,
+  UnexpectedFigletError
+};

src/figletFonts.ts

@@ -0,0 +1,59 @@
+import figlet from "figlet";
+import IFigletOptions from "./interfaces/IFigletOptions";
+import { UnexpectedFigletError } from './errors'
+
+class FigletFonts {
+
+  cachedFonts: Array<string>;
+  defaultFontOptions: IFigletOptions
+
+  constructor() {
+    this.cachedFonts = [];
+    this.defaultFontOptions = {
+      font: "Larry 3D",
+      horizontalLayout: "default",
+      verticalLayout: "default",
+      width: 80,
+      whitespaceBreak: true,
+    };
+  }
+
+  static sanitizeLarry(text: string) {
+    return text.replaceAll("L", "_");
+  }
+
+  generateText(text: string, options: IFigletOptions): Promise<string> {
+    const _options: IFigletOptions = {
+      ...this.defaultFontOptions,
+      ...options,
+    };
+
+    return new Promise((resolve, reject) => {
+      figlet.text(text, _options, (err, data) => {
+        if (err) {
+          return reject(new UnexpectedFigletError(err));
+        }
+
+        resolve(data);
+      });
+    });
+  }
+
+  get fonts(): Promise<Array<string>> {
+    if (this.cachedFonts.length > 0) {
+      return Promise.resolve(this.cachedFonts);
+    }
+
+    return new Promise((resolve, reject) => {
+      figlet.fonts((err, fonts) => {
+        if (err) {
+          return reject(new UnexpectedFigletError(err));
+        }
+
+        resolve(fonts);
+      });
+    });
+  }
+}
+
+export default FigletFonts;

src/interfaces/IFigletOptions.ts

@@ -0,0 +1,7 @@
+export default interface IFigletOptions {
+  font: string
+  horizontalLayout: string
+  verticalLayout: string
+  width: number
+  whitespaceBreak: boolean
+}

src/requiredQueryMiddleware.js

@@ -1,14 +0,0 @@
-const { MissingTextError } = require("./errors.js");
-
-const requiredQueryMiddleware = (req, res, next) => {
-  const { text } = req.query;
-
-  if (!text || text?.length === 0) {
-    const error = new MissingTextError();
-    return res.status(error?.statusCode || 500).send(error?.message);
-  }
-
-  next();
-};
-
-module.exports = requiredQueryMiddleware;

src/requiredQueryMiddleware.ts

@@ -0,0 +1,30 @@
+import FigletFonts from "./figletFonts";
+import { MissingTextError, FontNotFoundError } from "./errors";
+
+const figletFonts = new FigletFonts();
+
+async function doesFontExist(font: string) {
+  const fontLowercased = font.toLowerCase();
+
+  const fonts: Array<string> = await figletFonts.fonts
+  return fonts.findIndex((_font) => _font.toLowerCase() === fontLowercased) === -1;
+}
+
+const requiredQueryMiddleware = async (req, res, next) => {
+  const { text, font = "" } = req.query;
+  let error = null;
+
+  if (!text || text?.length === 0) {
+    error = new MissingTextError();
+  }
+
+  if (font && (await doesFontExist(font))) {
+    error = new FontNotFoundError(font, error);
+  }
+
+  if (error) return res.status(error?.statusCode || 500).send(error?.message);
+
+  next();
+};
+
+export default requiredQueryMiddleware;

tsconfig.json

@@ -0,0 +1,15 @@
+{
+  "compilerOptions": {
+    "allowJs": true,
+    "checkJs": false,
+    "target": "esnext",
+    "module": "commonjs",
+    "moduleResolution": "node",
+    "strict": false,
+    "esModuleInterop": true,
+    "lib": ["esnext", "dom"],
+    "outDir": "lib"
+  },
+  "include": ["src/**/*.js", "src/**/*.ts", "src/**/*.d.ts"],
+  "exclude": ["node_modules"]
+}