feat: add build-started and build-finished events (#122)

* feat: add build events

* docs: update readme with new events

README.md

@@ -338,10 +338,24 @@ serve({ config }).then((server) => {
 });
 ```
 
+#### build-started
+
+Arguments: [`Compiler`](https://webpack.js.org/api/node/#compiler-instance) _compiler_
+
+Emitted when a compiler has started a build.
+
+#### build-finished
+
+Arguments: [`Stats`](https://webpack.js.org/api/node/#stats-object) _stats_
+
+Emitted when a compiler has finished a build.
+
 #### listening
 
 Arguments: _None_
 
+Emitted when the server begins listening for connections.
+
 ## Add-on Features
 
 A core tenant of `webpack-serve` is to stay lean in terms of feature set, and to
@@ -435,4 +449,4 @@ We welcome your contributions! Please have a read of
 
 [dev-ware]: https://github.com/webpack/webpack-dev-middleware#options
 [hot-client]: https://github.com/webpack-contrib/webpack-hot-client#options
-[https-opts]: https://nodejs.org/api/tls.html#tls_tls_createsecurecontext_options
+[https-opts]: https://nodejs.org/api/tls.html#tls_tls_createsecurecontext_options

index.js

@@ -52,14 +52,19 @@ module.exports = (opts) => {
         if (stats.hasWarnings()) {
           bus.emit('compiler-warning', json);
         }
+
+        bus.emit('build-finished', stats);
       };
 
-      if (options.compiler.hooks) {
-        options.compiler.hooks.done.tap('WebpackServe', done);
-      } else {
-        options.compiler.plugin('done', done);
+      const compilers = options.compiler.compilers || [options.compiler];
+      for (const comp of compilers) {
+        comp.hooks.compile.tap('WebpackServe', () => {
+          bus.emit('build-started', comp);
+        });
       }
 
+      options.compiler.hooks.done.tap('WebpackServe', done);
+
       const { close, server, start } = getServer(options);
 
       start(options);

test/tests/events.js

@@ -41,4 +41,24 @@ describe('webpack-serve Events', () => {
       });
     });
   }).timeout(5e3);
+
+  it('should emit the build-started event', (done) => {
+    const config = load('./fixtures/basic/webpack.config.js');
+    serve({ config }).then((server) => {
+      server.on('build-started', () => {
+        assert(true);
+        setTimeout(() => { server.close(done); }, timeout);
+      });
+    });
+  }).timeout(5e3);
+
+  it('should emit the build-finished event', (done) => {
+    const config = load('./fixtures/basic/webpack.config.js');
+    serve({ config }).then((server) => {
+      server.on('build-finished', () => {
+        assert(true);
+        setTimeout(() => { server.close(done); }, timeout);
+      });
+    });
+  }).timeout(5e3);
 });