feature: Allow to pass server configuration

README.md

@@ -67,6 +67,20 @@ To make the pre-render browser visible and you would be available to debug.
 
 To see all the options available see this [documentation](https://github.com/Tribex/prerenderer#prerendererrenderer-puppeteer-options)
 
+### Renderer server configuration
+
+By default Prerender server start at first free port after 8000 as noted in [documentation](https://github.com/JoshTheDerf/prerenderer#server-options), but if your API require frontend to be run at specific port, you can pass server configuration as follows,
+
+```json
+{
+  "serverConfig": {
+    "port": 8100
+  }
+}
+```
+
+This might be helpful, for example, when API allows CORS headers only for requests from specific origins and not `http://localhost:8000` as in default configuration.
+
 ## What is Prerendering?
 
 To quote [prerender-spa-plugin](https://github.com/chrisvfritz/prerender-spa-plugin/blob/master/README.md):
@@ -84,5 +98,5 @@ To quote [prerender-spa-plugin](https://github.com/chrisvfritz/prerender-spa-plu
 
 ## Available Renderers
 
-Currently only `@prerenderer/renderer-puppeteer` is supported, although `@prerenderer/renderer-jsdom` 
+Currently only `@prerenderer/renderer-puppeteer` is supported, although `@prerenderer/renderer-jsdom`
 will probably be supported in the future

index.js

@@ -16,19 +16,22 @@ module.exports = function prerender(bundler) {
     const spinner = ora(chalk.grey('Prerendering')).start();
     let routes = ['/']; // the default route
     let rendererConfig = {};
+    let serverConfig = {};
     const found = await cosmiconfig('prerender').search();
     if (found) {
       const { config } = found;
       if (Array.isArray(config)) {
         routes = config;
       } else {
         if (config.rendererConfig) ({ rendererConfig } = config);
+        if (config.serverConfig) ({ serverConfig } = config);
         if (config.routes) ({ routes } = config);
       }
     }
     const { outDir } = bundler.options;
     const prerenderer = new Prerenderer({
       staticDir: outDir,
+      server: serverConfig,
       renderer: new Puppeteer(rendererConfig),
     });
     try {

tests/index.test.js

@@ -3,6 +3,7 @@ const childProcess = require('child_process');
 const { promisify } = require('util');
 const { promises: fs } = require('fs');
 const del = require('del');
+const detect = require('detect-port');
 const exec = promisify(childProcess.exec);
 
 function runBuild(filename) {
@@ -58,3 +59,11 @@ it('should run with an api call', async function () {
   expect(htmlFile).toEqual(expect.stringContaining('date of publication'));
   expect(htmlFile).toEqual(expect.stringContaining('Sample Slide Show'));
 });
+
+it('should work with custom server port', async function () {
+  const config = { serverConfig: { port: await detect(8110) } };
+  await fs.writeFile('.prerenderrc', JSON.stringify(config));
+  await runBuild('basic.html');
+  const htmlFile = await fs.readFile(pathJoin('dist', 'index.html'), 'utf-8');
+  expect(htmlFile).toEqual(expect.stringContaining(`${baseRoute}/`));
+})

tests/package.json

@@ -7,6 +7,7 @@
     "@abide-community/parcel-plugin-clean-out-dir": "^1.0.0",
     "cross-env": "^5.2.0",
     "del": "^5.0.0",
+    "detect-port": "^1.3.0",
     "jest": "^24.8.0",
     "parcel-bundler": "^1.12.3",
     "parcel-plugin-prerender": "file:../"