7 files changed, 38 insertions, 3 deletions

diff --git a/client/package.json b/client/package.json
index b8103d433..14c20e8d9 100644
--- a/client/package.json
+++ b/client/package.json
@@ -33,6 +33,7 @@
     "@angular/platform-browser": "~5.1.0",
     "@angular/platform-browser-dynamic": "~5.1.0",
     "@angular/router": "~5.1.0",
+    "@angularclass/hmr": "^2.1.3",
     "@ngx-meta/core": "^4.0.1",
     "@types/core-js": "^0.9.28",
     "@types/markdown-it": "^0.0.4",
diff --git a/client/src/environments/environment.prod.ts b/client/src/environments/environment.prod.ts
index c9f5a3b63..d5dfe5573 100644
--- a/client/src/environments/environment.prod.ts
+++ b/client/src/environments/environment.prod.ts
@@ -1,4 +1,5 @@
 export const environment = {
   production: true,
+  hmr: false,
   apiUrl: ''
 }
diff --git a/client/src/environments/environment.ts b/client/src/environments/environment.ts
index 43d788541..42b8baee8 100644
--- a/client/src/environments/environment.ts
+++ b/client/src/environments/environment.ts
@@ -5,5 +5,6 @@
 
 export const environment = {
   production: false,
+  hmr: true,
   apiUrl: 'http://localhost:9000'
 }
diff --git a/client/src/hmr.ts b/client/src/hmr.ts
new file mode 100644
index 000000000..4d707a250
--- /dev/null
+++ b/client/src/hmr.ts
@@ -0,0 +1,16 @@
+import { NgModuleRef, ApplicationRef } from '@angular/core'
+import { createNewHosts } from '@angularclass/hmr'
+
+export const hmrBootstrap = (module: any, bootstrap: () => Promise<NgModuleRef<any>>) => {
+  let ngModule: NgModuleRef<any>
+  module.hot.accept()
+  bootstrap()
+    .then(mod => ngModule = mod)
+  module.hot.dispose(() => {
+    const appRef: ApplicationRef = ngModule.injector.get(ApplicationRef)
+    const elements = appRef.components.map(c => c.location.nativeElement)
+    const makeVisible = createNewHosts(elements)
+    ngModule.destroy()
+    makeVisible()
+  })
+}
diff --git a/client/src/main.ts b/client/src/main.ts
index f3825fe50..b02b6830f 100644
--- a/client/src/main.ts
+++ b/client/src/main.ts
@@ -4,10 +4,22 @@ import { platformBrowserDynamic } from '@angular/platform-browser-dynamic'
 import { AppModule } from './app/app.module'
 import { environment } from './environments/environment'
 
+import { hmrBootstrap } from './hmr'
+
 if (environment.production) {
   enableProdMode()
 }
 
-platformBrowserDynamic()
+const bootstrap = () => platformBrowserDynamic()
   .bootstrapModule(AppModule)
-  .catch(err => console.log(err))
+
+if (environment.hmr) {
+  if (module[ 'hot' ]) {
+    hmrBootstrap(module, bootstrap)
+  } else {
+    console.error('HMR is not enabled for webpack-dev-server!')
+    console.log('Are you using the --hmr flag for ng serve?')
+  }
+} else {
+  bootstrap()
+}
diff --git a/client/yarn.lock b/client/yarn.lock
index b21624ec5..5c63a68a6 100644
--- a/client/yarn.lock
+++ b/client/yarn.lock
@@ -158,6 +158,10 @@
   dependencies:
     tslib "^1.7.1"
 
+"@angularclass/hmr@^2.1.3":
+  version "2.1.3"
+  resolved "https://registry.yarnpkg.com/@angularclass/hmr/-/hmr-2.1.3.tgz#34e658ed3da37f23b0a200e2da5a89be92bb209f"
+
 "@ngtools/json-schema@1.1.0", "@ngtools/json-schema@^1.1.0":
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/@ngtools/json-schema/-/json-schema-1.1.0.tgz#c3a0c544d62392acc2813a42c8a0dc6f58f86922"
diff --git a/scripts/watch/client.sh b/scripts/watch/client.sh
index b754ade76..6d4759b4e 100755
--- a/scripts/watch/client.sh
+++ b/scripts/watch/client.sh
@@ -2,4 +2,4 @@
 
 cd client || exit -1
 
-ng server --host localhost --port 3000
+ng server --hmr --host localhost --port 3000