From 8242834fbdd4956eed1b16cc3cfc43cb1188aecb Mon Sep 17 00:00:00 2001
From: Lea Anthony <lea.anthony@gmail.com>
Date: Mon, 27 Nov 2023 21:24:58 +1100
Subject: [PATCH] [windows] improvements to dev

---
 v3/internal/assetserver/assetserver.go        | 20 ++++++++--------
 v3/internal/commands/tool_checkport.go        | 23 +++++++++++++++++--
 .../templates/_common/Taskfile.tmpl.yml       |  5 ++++
 v3/pkg/application/application.go             |  3 ++-
 4 files changed, 37 insertions(+), 14 deletions(-)

diff --git a/v3/internal/assetserver/assetserver.go b/v3/internal/assetserver/assetserver.go
index 59b5faf0d..ba3a39076 100644
--- a/v3/internal/assetserver/assetserver.go
+++ b/v3/internal/assetserver/assetserver.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log/slog"
 	"math/rand"
+	"net"
 	"net/http"
 	"net/http/httptest"
 	"net/http/httputil"
@@ -99,28 +100,25 @@ func NewAssetServer(options *Options, servingFromDisk bool, logger *slog.Logger,
 	if result.devServerURL != "" {
 		logger.Info("Using External DevServer", "url", result.devServerURL)
 		// Parse devServerURL into url.URL
-		devserverURL, err := url.Parse(result.devServerURL)
+		devServerURL, err := url.Parse(result.devServerURL)
 		if err != nil {
 			return nil, err
 		}
-		result.wsHandler = httputil.NewSingleHostReverseProxy(devserverURL)
-		err = result.checkDevServerURL()
+		err = result.checkDevServerURL(devServerURL)
 		if err != nil {
 			return nil, err
 		}
+		result.wsHandler = httputil.NewSingleHostReverseProxy(devServerURL)
 	}
 	return result, nil
 }
 
-func (d *AssetServer) checkDevServerURL() error {
-	req, err := http.NewRequest("OPTIONS", "/", nil)
+func (d *AssetServer) checkDevServerURL(devServerURL *url.URL) error {
+	// Open a connection to the devserver URL
+	hostPort := devServerURL.Hostname() + ":" + devServerURL.Port()
+	_, err := net.DialTimeout("tcp", hostPort, 1*time.Second)
 	if err != nil {
-		return err
-	}
-	w := httptest.NewRecorder()
-	d.wsHandler.ServeHTTP(w, req)
-	if w.Code != http.StatusNoContent {
-		return fmt.Errorf("unable to connect to external server: %s. Please check it's running", d.devServerURL)
+		return fmt.Errorf("unable to connect to dev server: %s. Please check it's running", d.devServerURL)
 	}
 	return nil
 }
diff --git a/v3/internal/commands/tool_checkport.go b/v3/internal/commands/tool_checkport.go
index 1c209008c..db56d3171 100644
--- a/v3/internal/commands/tool_checkport.go
+++ b/v3/internal/commands/tool_checkport.go
@@ -3,10 +3,13 @@ package commands
 import (
 	"fmt"
 	"net"
+	"net/url"
+	"strconv"
 	"time"
 )
 
 type ToolCheckPortOptions struct {
+	URL  string `name:"u" description:"URL to check"`
 	Host string `name:"h" description:"Host to check" default:"localhost"`
 	Port int    `name:"p" description:"Port to check"`
 }
@@ -26,8 +29,24 @@ func isPortOpen(ip string, port int) bool {
 }
 
 func ToolCheckPort(options *ToolCheckPortOptions) error {
-	if options.Port == 0 {
-		return fmt.Errorf("please use the -p flag to specify a port")
+	if options.URL != "" {
+		// Parse URL
+		u, err := url.Parse(options.URL)
+		if err != nil {
+			return err
+		}
+		options.Host = u.Hostname()
+		options.Port, err = strconv.Atoi(u.Port())
+		if err != nil {
+			return err
+		}
+	} else {
+		if options.Port == 0 {
+			return fmt.Errorf("please use the -p flag to specify a port")
+		}
+		if !isPortOpen(options.Host, options.Port) {
+			return fmt.Errorf("port %d is not open on %s", options.Port, options.Host)
+		}
 	}
 	if !isPortOpen(options.Host, options.Port) {
 		return fmt.Errorf("port %d is not open on %s", options.Port, options.Host)
diff --git a/v3/internal/templates/_common/Taskfile.tmpl.yml b/v3/internal/templates/_common/Taskfile.tmpl.yml
index 8b138c63d..aa9c14f55 100644
--- a/v3/internal/templates/_common/Taskfile.tmpl.yml
+++ b/v3/internal/templates/_common/Taskfile.tmpl.yml
@@ -404,11 +404,16 @@ tasks:
   dev:frontend:
     summary: Runs the frontend in development mode
     dir: frontend
+    deps:
+      - task: install:frontend:deps
     cmds:
       - npm run dev
 
   dev:
     summary: Runs the application in development mode
+    preconditions:
+      - sh: wails3 tool checkport -u {{ "\"$WAILS_DEVSERVER_URL\"" }}
+        msg: "Looks like the devserver isn't available. Please ensure you have run `wails3 task dev:frontend` in another terminal."
     cmds:
       - wails3 tool watcher -path {{ "{{.PATH}}" }} -preexec {{ "\"{{.PREEXEC}}\""}} {{ "{{.PREWAIT}}" }} -postexec {{ "\"{{.POSTEXEC}}\"" }} -ignorefiles {{ "{{.IGNOREFILES}}" }} -ignoredirs {{ "{{.IGNOREDIRS}}" }} -ignoreextensions {{ "{{.IGNOREEXTENSIONS}}" }} -exec {{ "\"{{.EXEC}}\"" }} -debounce {{ "{{.DEBOUNCE}}" }}
     vars:
diff --git a/v3/pkg/application/application.go b/v3/pkg/application/application.go
index 881ed6a13..35fbc21e0 100644
--- a/v3/pkg/application/application.go
+++ b/v3/pkg/application/application.go
@@ -76,7 +76,8 @@ func New(appOptions Options) *App {
 
 	srv, err := assetserver.NewAssetServer(opts, false, result.Logger, wailsruntime.RuntimeAssetsBundle, result.isDebugMode, NewMessageProcessor(result.Logger))
 	if err != nil {
-		result.fatal(err.Error())
+		result.Logger.Error("Fatal error in application initialisation: " + err.Error())
+		os.Exit(1)
 	}
 
 	// Pass through the capabilities