From 3d4b119222e1fb337a1721292bcc6b6ff55c1b93 Mon Sep 17 00:00:00 2001
From: Aya Morisawa <AyaMorisawa4869@gmail.com>
Date: Sat, 31 Dec 2016 03:12:28 +0900
Subject: [PATCH] :sparkles:

---
 src/utils/dependencyChecker.ts | 38 ++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 src/utils/dependencyChecker.ts

diff --git a/src/utils/dependencyChecker.ts b/src/utils/dependencyChecker.ts
new file mode 100644
index 000000000..2036ebe36
--- /dev/null
+++ b/src/utils/dependencyChecker.ts
@@ -0,0 +1,38 @@
+import Logger from './logger';
+import { exec } from 'shelljs';
+
+export default class DependencyChecker {
+	logger: Logger;
+
+	constructor() {
+		this.logger = new Logger('Deps');
+	}
+
+	checkAll(): void {
+		this.logger.info('Checking started');
+		this.check('Node.js', 'node -v', x => x.match(/^v(.*)\r?\n$/));
+		this.check('npm', 'npm -v', x => x.match(/^(.*)\r?\n$/));
+		this.check('MongoDB', 'mongo --version', x => x.match(/^MongoDB shell version: (.*)\r?\n$/));
+		this.check('Redis', 'redis-server --version', x => x.match(/v=([0-9\.]*)/));
+		this.logger.info('Checking finished');
+	}
+
+	check(serviceName: string, command: string, transform: (x: string) => RegExpMatchArray): void {
+		const code = {
+			success: 0,
+			notFound: 127
+		};
+		const x = exec(command, { silent: true }) as any;
+		if (x.code === code.success) {
+			let ver = transform(x.stdout);
+			if (ver != null) {
+				this.logger.info(`${serviceName} ${ver[1]} found`);
+			} else {
+				this.logger.warn(`${serviceName} not found`);
+				this.logger.warn(`Regexp used for version check of ${serviceName} is probably messed up`);
+			}
+		} else if (x.code === code.notFound) {
+			this.logger.warn(`${serviceName} not found`);
+		}
+	}
+}