Allow chunking of imagemagick commands to prevent command line list t…

…oo long exceptions from child process

lib/generator.js

@@ -5,10 +5,14 @@ var async = require('async');
 var os = require('os');
 var path = require('path');
 var crypto = require("crypto");
+var util = require('util');
+var _ = require('underscore');
 
 var packing = require('./packing/packing.js');
 var sorter = require('./sorter/sorter.js');
 
+var BATCH_SIZE = 10;
+
 /**
  * Generate temporary trimmed image files
  * @param {string[]} files
@@ -114,6 +118,23 @@ exports.determineCanvasSize = function (files, options, callback) {
 	callback(null, options);
 };
 
+function makeCommands(fileList, options, index) {
+	return [
+		`convert -define png:exclude-chunks=date -quality 0% -size ${options.width}x${options.height} xc:none`,
+		index !== 0 &&
+			`"${options.path}/${options.name}.png" -composite`,
+		...fileList.map(
+			file =>
+				`"${file.path}" -geometry +${
+					(file.x + options.padding)}+${
+					(file.y + options.padding)} -composite`
+		),
+		`"${options.path}/${options.name}.png"`,
+	]
+		.filter(Boolean)
+		.join(" ");
+}
+
 /**
  * generates texture data file
  * @param {object[]} files
@@ -122,17 +143,25 @@ exports.determineCanvasSize = function (files, options, callback) {
  * @param {function} callback
  */
 exports.generateImage = function (files, options, callback) {
-	var command = ['convert -define png:exclude-chunks=date -quality 0% -size ' + options.width + 'x' + options.height + ' xc:none'];
-	files.forEach(function (file) {
-		command.push('"' + file.path + '" -geometry +' + (file.x + options.padding) + '+' + (file.y + options.padding) + ' -composite');
-	});
-	command.push('"' + options.path + '/' + options.name + '.png"');
-	exec(command.join(' '), function (err) {
-		if (err) return callback(err);
+	var fileBatches = _.chunk(files, BATCH_SIZE);
+	var commands = fileBatches.map((fileList, index) =>
+		makeCommands(fileList, options, index)
+	);
 
-		unlinkTempFiles(files);
-		callback(null);
-	});
+	var execPromise = util.promisify(exec);
+
+	var runAllCommands = async () => {
+		for (command of commands) {
+			await execPromise(command);
+		}
+	}
+
+	runAllCommands()
+		.then(() => {
+			unlinkTempFiles(files);
+			callback(null);
+		})
+		.catch(err => callback(err));
 };
 
 function unlinkTempFiles(files) {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "spritesheet-js",
-  "version": "1.2.6",
+  "version": "1.2.7",
   "description": "Spritesheet generator",
   "main": "index.js",
   "directories": {
@@ -17,7 +17,7 @@
     "mustache": "~0.7.2",
     "optimist": "~0.6.0",
     "platform-command": "git+https://gitlab.com/gitlabdev/platform-command.git",
-    "underscore": "~1.5.2"
+    "underscore": "1.9.2"
   },
   "devDependencies": {
     "mocha": "*",