fixup! lib: implement API versioning

lib/applications.js

@@ -1,5 +1,7 @@
 'use strict';
 
+const semver = require('semver');
+
 const errors = require('./errors');
 
 const apps = {};
@@ -8,14 +10,16 @@ module.exports = apps;
 // Generic application class. You are free to substitute it with whatever suits
 // your needs.
 //   name - application name
-//   api - application API
-//   version - api version of 'name' application
+//   api - object that contains interfaces as its fields each of which
+//         contains functions by method names. Each method has the following
+//         signature (connection, <0 or more method arguments>, callback)
+//   version - application version of 'name' application
 //
 class Application {
   constructor(name, api, version) {
-    this.name = name;
+    [this.name, this.version] = name.split('@');
+    if (!semver.valid(this.version)) this.version = version;
     this.api = api;
-    this.version = version;
   }
 
   // Call application method
@@ -69,19 +73,19 @@ apps.createAppsIndex = (applications) => {
     }
     if (!application.version) {
       // no version means latest version
-      if (appVersions.get('latest')) {
+      if (appVersions.has('latest')) {
         throw new Error(
           `Multiple entries of '${application.name} without version`
         );
       } else {
         appVersions.set('latest', application);
       }
     } else {
-      appVersions.set(application.version.toString(), application);
+      appVersions.set(application.version, application);
 
       // save latest version to fill missing latest versions later
       const latestApp = latestApps.get(application.name);
-      if (!latestApp || application.version > latestApp.version) {
+      if (!latestApp || semver.gt(application.version, latestApp.version)) {
         latestApps.set(application.name, application);
       }
     }

lib/server.js

@@ -1,5 +1,7 @@
 'use strict';
 
+const semver = require('semver');
+
 const apps = require('./applications');
 const Connection = require('./connection');
 const SimpleAuthPolicy = require('./simple-auth-policy');
@@ -24,6 +26,15 @@ const initServer = function(
     applications = apps.createAppsIndex(applications);
   }
 
+  // versions cached for efficient search when provided version is a range
+  this._cachedVersions = {};
+  applications.forEach((appVersions, appName) => {
+    this._cachedVersions[appName] =
+      Array.from(appVersions)
+           .filter(app => app[0] !== 'latest')
+           .sort((a, b) => semver.rcompare(a[0], b[0]));
+  });
+
   if (typeof(authPolicy) === 'number') {
     heartbeatInterval = authPolicy;
     authPolicy = null;
@@ -87,7 +98,22 @@ class Server {
   _getApplication(name, version) {
     const appVersions = this.applications.get(name);
     if (!appVersions) return null;
-    if (version) return appVersions.get(version);
+    if (version) {
+      // when version is not a range simply return matched
+      if (semver.valid(version)) return appVersions.get(version);
+
+      // search matching version, first matched will be the latest
+      try {
+        const range = new semver.Range(version);
+        for (const [ver, app] of this._cachedVersions[name]) {
+          if (range.test(ver)) return app;
+        }
+      } catch (error) {
+        // TODO (lundibundi): after loggers are implemented write using them
+        // console.info('Client provided invalid version: ', error);
+      }
+      return null;
+    }
     return appVersions.get('latest');
   }
 

package.json

@@ -35,6 +35,7 @@
     "./lib/simple-auth-policy.js": false
   },
   "dependencies": {
+    "semver": "^5.3.0",
     "websocket": "^1.0.24"
   },
   "devDependencies": {

test/node/api-versions.js

@@ -30,8 +30,8 @@ const interfacesVLatest = {
   }
 };
 
-const appV1 = new jstp.Application(app.name, interfacesV1, 1);
-const appV2 = new jstp.Application(app.name, interfacesV2, 2);
+const appV1 = new jstp.Application(app.name, interfacesV1, '1.0.0');
+const appV2 = new jstp.Application(app.name, interfacesV2, '2.0.0');
 const appVlatest = new jstp.Application(app.name, interfacesVLatest);
 
 let server;
@@ -42,10 +42,16 @@ test.afterEach((done) => {
     connection.close();
     connection = null;
   }
-  server.close();
+  if (server) server.close();
   done();
 });
 
+test.test('must allow to specify version in application name', (test) => {
+  const appV1 = new jstp.Application('app@1.0.0', interfacesV1);
+  test.strictSame(appV1.version, '1.0.0');
+  test.end();
+});
+
 test.test('must handle specific versions', (test) => {
   const serverConfig = {
     applications: [appV1, appV2, appVlatest], authPolicy: app.authCallback
@@ -95,6 +101,45 @@ test.test('must handle specific versions', (test) => {
   });
 });
 
+test.test('must handle version ranges', (test) => {
+  const serverConfig = {
+    applications: [appV1, appV2, appVlatest], authPolicy: app.authCallback
+  };
+  server = jstp.net.createServer(serverConfig);
+  server.listen(0, () => {
+    test.plan(6);
+
+    const port = server.address().port;
+
+    let client = null;
+    // ^1.0.0
+    client = {
+      connectPolicy: new jstp.SimpleConnectPolicy(null, null, '^1.0.0')
+    };
+    jstp.net.connect(app.name, client, port, (error, conn) => {
+      test.assertNot(error, 'connect must not return an error');
+      conn.callMethod('calculator', 'answer', [], (error, result) => {
+        test.assertNot(error, 'callMethod must not return an error');
+        test.strictSame(result, 42);
+        conn.close();
+      });
+    });
+
+    // > v1.0.0
+    client = {
+      connectPolicy: new jstp.SimpleConnectPolicy(null, null, '>1.0.0')
+    };
+    jstp.net.connect(app.name, client, port, 'localhost', (error, conn) => {
+      test.assertNot(error, 'connect must not return an error');
+      conn.callMethod('calculator', 'answer', [], (error, result) => {
+        test.assertNot(error, 'callMethod must not return an error');
+        test.strictSame(result, 24);
+        conn.close();
+      });
+    });
+  });
+});
+
 test.test('must return an error on connect to nonexistent version', (test) => {
   const serverConfig =
     { applications: [appV1, appV2, appVlatest], authPolicy: app.authCallback };