begin new custom chart implementation for js ui

go/jsbundler/js.go

@@ -26,10 +26,12 @@ func esbuildDefine() map[string]string {
 }
 
 // resolveEntryPoint returns the path (relative to frontendDir) of the
-// SPA entry point, preferring app.tsx over app.js.
+// SPA entry point, preferring app.tsx, then app.ts, then app.js.
 func resolveEntryPoint() string {
-	if _, err := os.Stat(filepath.Join(frontendDir, "src/app.tsx")); err == nil {
-		return "src/app.tsx"
+	for _, e := range []string{"src/app.tsx", "src/app.ts"} {
+		if _, err := os.Stat(filepath.Join(frontendDir, e)); err == nil {
+			return e
+		}
 	}
 	return "src/app.js"
 }
@@ -79,8 +81,16 @@ func bundleJSEntry(entry, outName string) (bundleStats, error) {
 	plugins := []esbuild.Plugin{aliasPlugin(), defaultExportShimPlugin(), Plugin()}
 	plugins = append(plugins, assetURLPlugin(), vendorManifestPlugin(entrypoints, vdirs))
 
+	// esbuild wants forward slashes and a leading "./"; a relative path with the
+	// OS separator (filepath.Join gives backslashes on Windows) or without "./" is
+	// read as a bare package specifier and fails to resolve.
+	entryPath := filepath.ToSlash(entry)
+	if !filepath.IsAbs(entry) && !strings.HasPrefix(entryPath, "./") && !strings.HasPrefix(entryPath, "../") {
+		entryPath = "./" + entryPath
+	}
+
 	result := esbuild.Build(esbuild.BuildOptions{
-		EntryPoints:       []string{entry},
+		EntryPoints:       []string{entryPath},
 		Outfile:           filepath.Join(outputDir, outName),
 		Bundle:            true,
 		Write:             true,