Reimplement hashFile locally

Replace the 10 MB of dependencies that is hash-files with a homebrew
Promise based implementation of hashFile that uses crypto and fs.  This
somehow also ends up being the same amount of code as the one using
hash-files.

client.js

@@ -8,7 +8,6 @@ const syncRequest = require('sync-request');
 const request = require("request");
 const ncp = require('ncp').ncp;
 const Rcon = require('rcon-client-fork').Rcon;
-const hashFiles = require('hash-files');
 const _ = require('underscore');
 const deepmerge = require("deepmerge");
 const getMac = require('getmac').getMac;
@@ -20,6 +19,7 @@ const objectOps = require("lib/objectOps.js");
 const fileOps = require("lib/fileOps");
 const stringUtils = require("lib/stringUtils.js");
 const configManager = require("lib/manager/configManager.js");
+const hashFile = require('lib/hash').hashFile;
 
 // argument parsing
 const args = require('minimist')(process.argv.slice(2));
@@ -773,42 +773,22 @@ function hashMods(instanceName, callback) {
 	if(!callback) {
 		throw new Error("ERROR in function hashMods NO CALLBACK");
 	}
-	function callback2(hash, modName){
-		hashedMods[hashedMods.length] = {
-			modName: modName,
-			hash: hash,
-		};
-		// check if this callback has ran once for each mod
-		if(hashedMods.length == instanceMods.length) {
-			callback(hashedMods);
-		}
-		//console.log(modname);
-	}
-	let hashedMods = [];
-	/*let mods = fs.readdirSync("./sharedMods/")*/
-	let instanceMods = fs.readdirSync(config.instanceDirectory+"/"+instanceName+"/mods/");
-	if(instanceMods.length == 0){
-		callback({}); // there are no mods installed, return an empty object
-	}
-	for(let o=0;o<instanceMods.length;o++) {
-		if(path.extname(instanceMods[o]) != ".zip") {
-			instanceMods.splice(instanceMods.indexOf(instanceMods[o]), 1); // remove element from array, we can't hash unzipped mods
+
+	let modsDir = config.instanceDirectory+"/"+instanceName+"/mods/";
+	function hashMod(name) {
+		if (path.extname(name) != ".zip") {
+			// Can't hash unzipped mods, return null that's filtered out later
+			return null;
+		} else {
+			return hashFile(modsDir+name).then(hash => (
+				{modName: name, hash: hash}
+			));
 		}
 	}
-	for(let i=0; i<instanceMods.length; i++){
-		let path = config.instanceDirectory+"/"+instanceName+"/mods/"+instanceMods[i];
-		let name = instanceMods[i];
-		let options = {
-			files:path,
-		};
-		// options {files:[array of paths]}
-		hashFiles(options, function(error, hash) {
-			// hash will be a string if no error occurred
-			if(!error){
-				callback2(hash, name);
-			} else {
-				throw error;
-			}
-		});
-	}
+
+	let promises = fs.readdirSync(modsDir).map(hashMod);
+	Promise.all(promises).then(hashes => {
+		// Remove null entries from hashMod
+		callback(hashes.filter(entry => entry !== null));
+	});
 }

lib/hash.js

@@ -0,0 +1,22 @@
+const crypto = require('crypto');
+const fs = require('fs');
+
+/**
+ * Returns a promise that resolves to the SHA1 hash of the file given by path
+ */
+exports.hashFile = function(path) {
+	return new Promise(function(resolve, reject) {
+		let hasher = crypto.createHash('sha1')
+		hasher.setEncoding('hex')
+		hasher.on('finish', function() {
+			resolve(hasher.read());
+		});
+
+		let stream = fs.createReadStream(path);
+		stream.on('error', function(error) {
+			// the docs doesn't say anything about what's passed on error
+			reject(error);
+		});
+		stream.pipe(hasher);
+	});
+}

package.json

@@ -39,7 +39,6 @@
     "follow-redirects": "^1.5.0",
     "fs-extra": "^6.0.1",
     "getmac": "^1.4.0",
-    "hash-files": "^1.1.1",
     "html5-validator": "^1.0.7",
     "ini": "^1.3.5",
     "jsonwebtoken": "^8.2.1",