Server graph only (#114)

* Added `--graph-only` option for the `orca serve` entry point

When this option is present, only the plotly-graph component is run
(not thumbnail, dash, etc.).

When graph conversion is the only service needed, this option
reduces the number of electron processes, the memory usage,
and startup time.

Author: jonmmease

Diff for: bin/serve.js

@@ -27,6 +27,11 @@ const OPTS_META = [].concat([{
   type: 'string',
   alias: ['windowMaxNumber', 'maxNumberOfWindows'],
   description: 'Sets maximum number of browser windows the server can keep open at a given time.'
+}, {
+  name: 'graph-only',
+  type: 'boolean',
+  alias: ['graphOnly'],
+  description: 'Launches only the graph component (not thumbnails, dash, etc.) to save memory and reduce the number of processes.'
 }, {
   name: 'quiet',
   type: 'boolean',
@@ -72,15 +77,14 @@ function main (args) {
       console.log(`Spinning up server with pid: ${process.pid}`)
     }
 
-    app = orca.serve({
-      port: opts.port,
-      maxNumberOfWindows: opts.maxNumberOfWindows,
-      debug: opts.debug,
-      component: [{
-        name: 'plotly-graph',
-        route: '/',
-        options: plotlyJsOpts
-      }, {
+    let component = [{
+      name: 'plotly-graph',
+      route: '/',
+      options: plotlyJsOpts
+    }]
+
+    if (!opts.graphOnly) {
+      component.push({
         name: 'plotly-dashboard',
         route: '/dashboard'
       }, {
@@ -98,7 +102,14 @@ function main (args) {
       }, {
         name: 'plotly-dash-preview',
         route: '/dash-preview'
-      }]
+      })
+    }
+
+    app = orca.serve({
+      port: opts.port,
+      maxNumberOfWindows: opts.maxNumberOfWindows,
+      debug: opts.debug,
+      component: component
     })
 
     app.on('after-connect', (info) => {

Diff for: test/integration/orca_serve_graph-only_test.js

@@ -0,0 +1,82 @@
+const tap = require('tap')
+const Application = require('spectron').Application
+const request = require('request')
+
+const { paths } = require('../common')
+const PORT = 9109
+const SERVER_URL = `http://localhost:${PORT}`
+
+const app = new Application({
+  path: paths.bin,
+  args: ['serve', '--port', PORT, '--graph-only']
+})
+
+tap.tearDown(() => {
+  if (app && app.isRunning()) {
+    app.stop()
+  }
+})
+
+tap.test('should launch', t => {
+  app.start().then(() => {
+    app.client.getWindowCount().then(cnt => {
+      // Only one window since only graph component should be running
+      t.equal(cnt, 1)
+      t.end()
+    })
+  })
+})
+
+tap.test('should reply pong to ping POST', t => {
+  request.post(SERVER_URL + '/ping', (err, res, body) => {
+    if (err) t.fail(err)
+
+    t.equal(res.statusCode, 200, 'code')
+    t.equal(body, 'pong', 'body')
+    t.end()
+  })
+})
+
+tap.test('should work for *plotly-graph* component', t => {
+  request({
+    method: 'POST',
+    url: SERVER_URL + '/',
+    body: JSON.stringify({
+      figure: {
+        layout: {
+          data: [{y: [1, 2, 1]}]
+        }
+      }
+    })
+  }, (err, res, body) => {
+    if (err) t.fail(err)
+
+    t.equal(res.statusCode, 200, 'code')
+    t.type(body, 'string')
+    t.end()
+  })
+})
+
+tap.test('should teardown', t => {
+  app.stop()
+    .catch(t.fail)
+    .then(t.end)
+})
+
+tap.test('should not work for *plotly-thumbnail* component', t => {
+  request({
+    method: 'POST',
+    url: SERVER_URL + '/thumbnail',
+    body: JSON.stringify({
+      figure: {
+        layout: {
+          data: [{y: [1, 2, 1]}]
+        }
+      }
+    })
+  }, (err, res) => {
+    t.equal(err.code, 'ECONNREFUSED')
+    t.equal(res, undefined, 'should be undefined')
+    t.end()
+  })
+})