move datalayout to separate file for tests

src/datalayout.js

@@ -0,0 +1,55 @@
+'use strict';
+
+let assert = require('assert'),
+    path = require('path');
+
+class DataLayout {
+    constructor(localRoot, dirMap) {
+        assert.strictEqual(typeof localRoot, 'string');
+        assert(Array.isArray(dirMap), 'Expecting layout to be an array');
+
+        this._localRoot = localRoot;
+        this._dirMap = dirMap;
+        this._remoteRegexps = dirMap.map((l) => new RegExp('^\\./' + l.remoteDir + '/?'));
+        this._localRegexps = dirMap.map((l) => new RegExp('^' + l.localDir + '/?'));
+    }
+    toLocalPath(remoteName) {
+        assert.strictEqual(typeof remoteName, 'string');
+
+        for (let i = 0; i < this._remoteRegexps.length; i++) {
+            if (!remoteName.match(this._remoteRegexps[i])) continue;
+            return remoteName.replace(this._remoteRegexps[i], this._dirMap[i].localDir + '/'); // make paths absolute
+        }
+        return remoteName.replace(new RegExp('^\\.'), this._localRoot);
+    }
+    toRemotePath(localName) {
+        assert.strictEqual(typeof localName, 'string');
+
+        for (let i = 0; i < this._localRegexps.length; i++) {
+            if (!localName.match(this._localRegexps[i])) continue;
+            return localName.replace(this._localRegexps[i], './' + this._dirMap[i].remoteDir + '/'); // make paths relative
+        }
+        return localName.replace(new RegExp('^' + this._localRoot + '/?'), './');
+    }
+    localRoot() {
+        return this._localRoot;
+    }
+    getBasename() { // used to generate cache file names
+        return path.basename(this._localRoot);
+    }
+    toString() {
+        return JSON.stringify({ localRoot: this._localRoot, layout: this._dirMap });
+    }
+    localPaths() {
+        return [ this._localRoot ].concat(this._dirMap.map((l) => l.localDir));
+    }
+    directoryMap() {
+        return this._dirMap;
+    }
+    static fromString(str) {
+        const obj = JSON.parse(str);
+        return new DataLayout(obj.localRoot, obj.layout);
+    }
+}
+
+exports = module.exports = DataLayout;