Brush up the go code

cmd/covergen/main.go

@@ -13,6 +13,7 @@ import (
 	"covergen/pkg/covergen"
 )
 
+// List of colors used for picking a (random) color in the cli
 var colors = []string{"red", "blue", "yellow", "green"}
 var colorMap = map[string]covergen.Color{
 	"red":    {255, 85, 0},
@@ -69,6 +70,7 @@ func main() {
 		chosenColor = colorMap[*color]
 	}
 
+	// Newlines in CLI arguments are given escaped. Unescape them to proper newlines
 	*customer = strings.ReplaceAll(*customer, "\\n", "\n")
 	settings := covergen.CoverSettings{
 		Number:       *number,
@@ -77,6 +79,7 @@ func main() {
 		HLColor:      chosenColor,
 	}
 
+	// If output2 (back page) is not set, generate a combined PDF
 	if *output2 == "" {
 		pdf, err := covergen.GenerateInvoice(settings)
 
@@ -88,6 +91,7 @@ func main() {
 			log.Fatal().Err(err).Msg("Failed to write invoice to disk")
 		}
 	} else {
+		// Otherwise, generate the front and back separately
 		front, err := covergen.GenerateFrontCover(settings)
 		if err != nil {
 			log.Fatal().Err(err).Msg("Failed to render front")

cmd/server/main.go

@@ -5,6 +5,7 @@ import (
 	"net/http"
 )
 
+// Super simple development webserver
 func main() {
 	err := http.ListenAndServe(":9090", http.FileServer(http.Dir("assets")))
 	if err != nil {

cmd/wasm/main.go

@@ -12,6 +12,7 @@ import (
 	"covergen/pkg/covergen"
 )
 
+// jsmap is just a type alias that corresponds to the ES5 Record<string, any>, or just a plain object {}
 type jsmap = map[string]interface{}
 
 type covergenArgs struct {
@@ -21,6 +22,8 @@ type covergenArgs struct {
 	HLColor      string `jsref:"hlColor"`
 }
 
+// parseHexColor takes a CSS hex color (#RRGGBB or the shorthand #RGB) and parses out the red, green, and blue components
+// into a covergen.Color
 func parseHexColor(s string) (c covergen.Color, err error) {
 	switch len(s) {
 	case 7:
@@ -33,11 +36,12 @@ func parseHexColor(s string) (c covergen.Color, err error) {
 		c.B *= 17
 	default:
 		err = fmt.Errorf("invalid length, must be 7 or 4")
-
 	}
+
 	return
 }
 
+// settingsFromValue tries to parse the WASM boundary-crossing arguments blob into a golang-native settings object
 func settingsFromValue(arg js.Value) (*covergen.CoverSettings, error) {
 	settings := covergenArgs{
 		NumberPrefix: "offerte",
@@ -71,6 +75,7 @@ func settingsFromValue(arg js.Value) (*covergen.CoverSettings, error) {
 	}, nil
 }
 
+// pdfToJs takes the pdf object and outputs it into a Uint8Array and passes that back to JS.
 func pdfToJs(pdf *fpdf.Fpdf) (js.Value, error) {
 	var buf bytes.Buffer
 	if err := pdf.Output(&buf); err != nil {
@@ -83,10 +88,11 @@ func pdfToJs(pdf *fpdf.Fpdf) (js.Value, error) {
 	return ta, nil
 }
 
+// generateCover is the JS exposed entrypoint to generate a 2 page pdf with both the front and back cover
 func generateCover(this js.Value, args []js.Value) interface{} {
 	defer func() {
 		if r := recover(); r != nil {
-			fmt.Println("recovered", r)
+			fmt.Printf("recovered from critical error: %+v", r)
 		}
 	}()
 
@@ -119,7 +125,7 @@ func generateCover(this js.Value, args []js.Value) interface{} {
 func generateSplitCover(this js.Value, args []js.Value) interface{} {
 	defer func() {
 		if r := recover(); r != nil {
-			fmt.Println("recovered", r)
+			fmt.Printf("recovered from critical error: %+v", r)
 		}
 	}()