Use semver to define which version to load (fix #108)

This also:

- dynamically builds the available versions by listing
  the versions directories.
- introduces module.latest, that point to the latest version
  id available

Using "semver" module, this will also allow much advanced loading
syntax (like ranges, carret, star or x…).

index.js

@@ -1,30 +1,39 @@
 var fs = require('fs'),
     path = require('path'),
-    existsSync = require('fs').existsSync || require('path').existsSync;
+    semver = require('semver'),
+    existsSync = require('fs').existsSync || path.existsSync;
 
-var versions = [
- '2.0.0',
- '2.0.1',
- '2.0.2',
- '2.1.0',
- '2.1.1',
- '2.2.0',
- '2.3.0',
- '3.0.0',
- '3.0.3',
- '3.0.4'
-];
 
-module.exports.versions = versions;
+var getVersions = function () {
+    var names = fs.readdirSync('./'), versions = [];
+    for (var i = 0; i < names.length; i++) {
+        if(names[i].match(/^\d{1,2}\.\d{1,2}\.\d{1,2}$/)) versions.push(names[i]);
+    };
+    return versions;
+};
+var versions = getVersions();
+
+var getSatisfyingVersion = function (wanted) {
+    var version = semver.maxSatisfying(versions, wanted), parsed;
+    if (!version) {
+        parsed = semver(wanted);
+        parsed.patch = 'x';
+        version = semver.maxSatisfying(versions, parsed.format());
+    }
+    return version;
+};
 
-module.exports.load = function(version) {
-    if (versions.indexOf(version) <= -1) {
-	throw new Error("Unknown mapnik-reference version: '" + version + "'");
+module.exports.versions = versions;
+module.exports.latest = versions[versions.length - 1];
+module.exports.load = function(wanted) {
+    var version = getSatisfyingVersion(wanted);
+    if (!version) {
+        throw new Error("Unknown mapnik-reference version: '" + wanted + "'");
     }
     var ref = require(path.join(__dirname, version, 'reference.json'));
     var ds_path = path.join(__dirname, version, 'datasources.json');
     if (existsSync(ds_path)) {
-	ref.datasources = require(ds_path).datasources;
+	   ref.datasources = require(ds_path).datasources;
     }
     return ref;
 }

package.json

@@ -8,10 +8,13 @@
     "url": "git://github.com/mapnik/mapnik-reference.git"
   },
   "scripts": {
-      "test": "mocha -R spec --timeout 50000"
+    "test": "mocha -R spec --timeout 50000"
   },
   "devDependencies": {
     "mocha": "1.x",
-    "glob":"4.x"
+    "glob": "4.x"
+  },
+  "dependencies": {
+    "semver": "^5.0.3"
   }
 }

test/test.js

@@ -43,3 +43,53 @@ describe('versions', function() {
 });
 
 
+
+describe('load', function() {
+    it('should load requested version if exists', function() {
+        var spec = mapnikref.load('2.0.2');
+        assert.equal(spec.version, '2.0.2');
+    });
+
+    it('should load closer patch version if requested patch does not exist', function() {
+        var spec = mapnikref.load('2.0.12');
+        assert.equal(spec.version, '2.0.2');
+    });
+
+    it('should support x as patch', function() {
+        var spec = mapnikref.load('2.0.x');
+        assert.equal(spec.version, '2.0.2');
+    });
+
+    it('should support x as minor', function() {
+        var spec = mapnikref.load('2.x.x');
+        assert.equal(spec.version, '2.3.0');
+    });
+
+    it('should support missing patch', function() {
+        var spec = mapnikref.load('2.3');
+        assert.equal(spec.version, '2.3.0');
+    });
+
+    it('should support major only', function() {
+        var spec = mapnikref.load('2');
+        assert.equal(spec.version, '2.3.0');
+    });
+
+    it('should support range', function() {
+        var spec = mapnikref.load('2.x < 3');
+        assert.equal(spec.version, '2.3.0');
+    });
+
+    it('should support *', function() {
+        var spec = mapnikref.load('*');
+        assert.equal(spec.version, mapnikref.latest);
+    });
+
+    it('should throw if requested minor does not exist', function() {
+        assert.throws(function () {
+            mapnikref.load('2.12.0');
+        }, /Unknown mapnik-reference version/);
+    });
+});
+
+