Add WASM build support with modern Go

Makefile

@@ -47,5 +47,12 @@ format: ## Formats the code. Must have goimports installed (use make install-lin
 	goimports -w -local github.com/skycoin/skycoin-lite ./mobile
 	goimports -w -local github.com/skycoin/skycoin-lite ./main.go
 
+build-wasm: ## Generate WASM files for both Go and TinyGo
+	@echo "Building WASM files..."
+	go run ./cmd/gen
+	@echo "Updating dependencies..."
+	go mod tidy
+	go mod vendor
+
 help:
 	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}'

cmd/gen/gen.go

@@ -0,0 +1,129 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"time"
+
+	"github.com/bitfield/script"
+	"github.com/briandowns/spinner"
+	"github.com/spf13/cobra"
+)
+
+var (
+	wasmSourceDir string
+	outputGoDir   string
+	outputTinyDir string
+	wasmFileName  string
+)
+
+func main() {
+	rootCmd := &cobra.Command{
+		Use:   "gen",
+		Short: "Generate WASM files for Go and TinyGo",
+		Long:  `Compiles WASM from source using both Go and TinyGo, and copies their respective wasm_exec.js files.`,
+		Run:   run,
+	}
+
+	rootCmd.Flags().StringVarP(&wasmSourceDir, "source", "s", "wasm", "Directory containing WASM source code")
+	rootCmd.Flags().StringVarP(&outputGoDir, "go-output", "g", "wasm-go", "Output directory for Go-compiled WASM")
+	rootCmd.Flags().StringVarP(&outputTinyDir, "tinygo-output", "t", "wasm-tinygo", "Output directory for TinyGo-compiled WASM")
+	rootCmd.Flags().StringVarP(&wasmFileName, "filename", "f", "skycoin-lite.wasm", "Output WASM filename")
+
+	if err := rootCmd.Execute(); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}
+
+func run(cmd *cobra.Command, args []string) {
+	// Validate source directory exists
+	if _, err := os.Stat(wasmSourceDir); os.IsNotExist(err) {
+		log.Fatalf("Source directory does not exist: %s", wasmSourceDir)
+	}
+
+	// Create output directories
+	os.MkdirAll(outputGoDir, 0755)
+	os.MkdirAll(outputTinyDir, 0755)
+
+	// Copy wasm_exec.js files
+	copyWasmExecJS()
+
+	// Compile WASM files
+	compileWASM()
+}
+
+func copyWasmExecJS() {
+	fmt.Println("Copying wasm_exec.js files...")
+
+	// Go's wasm_exec.js
+	goWasmExec := filepath.Join(runtime.GOROOT(), "misc", "wasm", "wasm_exec.js")
+	if _, err := os.Stat(goWasmExec); os.IsNotExist(err) {
+		// Try alternate location for Go 1.21+
+		goWasmExec = filepath.Join(runtime.GOROOT(), "lib", "wasm", "wasm_exec.js")
+	}
+
+	// TinyGo's wasm_exec.js
+	tinygoRoot := strings.TrimSuffix(runtime.GOROOT(), "go") + "tinygo"
+	tinygoWasmExec := filepath.Join(tinygoRoot, "targets", "wasm_exec.js")
+
+	// Copy Go wasm_exec.js
+	if _, err := script.File(goWasmExec).WriteFile(filepath.Join(outputGoDir, "wasm_exec.js")); err != nil {
+		log.Fatalf("Failed to copy Go wasm_exec.js: %v", err)
+	}
+	fmt.Printf("✓ Copied %s/wasm_exec.js\n", outputGoDir)
+
+	// Copy TinyGo wasm_exec.js
+	if _, err := script.File(tinygoWasmExec).WriteFile(filepath.Join(outputTinyDir, "wasm_exec.js")); err != nil {
+		log.Fatalf("Failed to copy TinyGo wasm_exec.js: %v", err)
+	}
+	fmt.Printf("✓ Copied %s/wasm_exec.js\n", outputTinyDir)
+}
+
+func compileWASM() {
+	s := spinner.New(spinner.CharSets[14], 25*time.Millisecond)
+
+	// Compile with Go
+	s.Suffix = " Compiling with Go..."
+	s.Start()
+
+	goOutput := filepath.Join(outputGoDir, wasmFileName)
+	goBuildCmd := fmt.Sprintf(
+		`bash -c 'cd %s || exit 1 ; time GOOS=js GOARCH=wasm go build -o ../%s -ldflags="-s -w" . && cd .. && du -h %s'`,
+		wasmSourceDir, goOutput, goOutput,
+	)
+	fmt.Println("\nRunning:", goBuildCmd)
+
+	output, err := script.Exec(goBuildCmd).String()
+	s.Stop()
+	if err != nil {
+		log.Fatalf("Go build failed: %v\nOutput: %s", err, output)
+	}
+	fmt.Println(output)
+	fmt.Printf("✓ Compiled %s\n", goOutput)
+
+	// Compile with TinyGo
+	s.Suffix = " Compiling with TinyGo..."
+	s.Start()
+
+	tinyOutput := filepath.Join(outputTinyDir, wasmFileName)
+	tinyGoBuildCmd := fmt.Sprintf(
+		`bash -c 'cd %s || exit 1 ; time GOOS=js GOARCH=wasm tinygo build -target=wasm --no-debug -o ../%s . && cd .. && du -h %s'`,
+		wasmSourceDir, tinyOutput, tinyOutput,
+	)
+	fmt.Println("\nRunning:", tinyGoBuildCmd)
+
+	output, err = script.Exec(tinyGoBuildCmd).String()
+	s.Stop()
+	if err != nil {
+		log.Fatalf("TinyGo build failed: %v\nOutput: %s", err, output)
+	}
+	fmt.Println(output)
+	fmt.Printf("✓ Compiled %s\n", tinyOutput)
+
+	fmt.Println("\n✅ All WASM files generated successfully!")
+}

go.mod

@@ -0,0 +1,24 @@
+module github.com/skycoin/skycoin-lite
+
+go 1.25.1
+
+require (
+	github.com/bitfield/script v0.24.1
+	github.com/briandowns/spinner v1.23.2
+	github.com/gopherjs/gopherjs v1.17.2
+	github.com/skycoin/skycoin v0.28.0
+	github.com/spf13/cobra v1.2.1
+)
+
+require (
+	github.com/fatih/color v1.7.0 // indirect
+	github.com/inconshreveable/mousetrap v1.0.0 // indirect
+	github.com/itchyny/gojq v0.12.13 // indirect
+	github.com/itchyny/timefmt-go v0.1.5 // indirect
+	github.com/mattn/go-colorable v0.1.2 // indirect
+	github.com/mattn/go-isatty v0.0.19 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
+	golang.org/x/sys v0.10.0 // indirect
+	golang.org/x/term v0.8.0 // indirect
+	mvdan.cc/sh/v3 v3.7.0 // indirect
+)