feat(cli): add node version check

See #70 and #71.

package.json

@@ -51,13 +51,15 @@
     "listr": "0.14.3",
     "marked": "0.8.2",
     "puppeteer": ">=2.0.0",
+    "semver": "7.3.2",
     "serve-handler": "6.1.2"
   },
   "devDependencies": {
     "@types/highlight.js": "9.12.3",
     "@types/listr": "0.14.2",
     "@types/marked": "0.7.4",
     "@types/puppeteer": "2.0.1",
+    "@types/semver": "7.1.0",
     "@types/serve-handler": "6.1.0",
     "ava": "3.7.0",
     "husky": "4.2.5",

src/cli.ts

@@ -10,11 +10,13 @@ import getPort from 'get-port';
 import getStdin from 'get-stdin';
 import Listr from 'listr';
 import path from 'path';
+import { PackageJson } from '.';
 import { Config, defaultConfig } from './lib/config';
 import { help } from './lib/help';
 import { setProcessAndTermTitle } from './lib/helpers';
 import { convertMdToPdf } from './lib/md-to-pdf';
 import { closeServer, serveDirectory } from './lib/serve-dir';
+import { validateNodeVersion } from './lib/validate-node-version';
 
 // --
 // Configure CLI Arguments
@@ -59,8 +61,12 @@ main(cliFlags, defaultConfig).catch((error) => {
 async function main(args: typeof cliFlags, config: Config) {
 	setProcessAndTermTitle('md-to-pdf');
 
+	if (!validateNodeVersion()) {
+		throw new Error('Please use a Node.js version that satisfies the version specified in the engines field.');
+	}
+
 	if (args['--version']) {
-		return console.log((require('../package') as { version: string }).version);
+		return console.log((require('../package') as PackageJson).version);
 	}
 
 	if (args['--help']) {

src/index.ts

@@ -42,3 +42,10 @@ export const mdToPdf = async (input: { path: string } | { content: string }, con
 };
 
 export default mdToPdf;
+
+export interface PackageJson {
+	engines: {
+		node: string;
+	};
+	version: string;
+}

src/lib/validate-node-version.ts

@@ -0,0 +1,6 @@
+import semver from 'semver';
+import { PackageJson } from '..';
+
+const pkg: PackageJson = require('../../package');
+
+export const validateNodeVersion = () => semver.satisfies(process.versions.node, pkg.engines.node);