Removed old impl

resolver-go/cmd/externs-gen/main.go

@@ -0,0 +1,87 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"go/format"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+func main() {
+	src := flag.String("src", "./src", "BotanJS source root")
+	out := flag.String("out", "internal/generated/externs_gen.go", "generated Go output")
+	pkg := flag.String("pkg", "generated", "generated package name")
+	flag.Parse()
+
+	if err := os.MkdirAll(filepath.Dir(*out), 0o755); err != nil {
+		fatal(err)
+	}
+
+	code, err := render(*pkg, *src)
+	if err != nil {
+		fatal(err)
+	}
+
+	fmted, err := format.Source([]byte(code))
+	if err != nil {
+		_, _ = os.Stderr.WriteString(code)
+		fatal(err)
+	}
+
+	if err := os.WriteFile(*out, fmted, 0o644); err != nil {
+		fatal(err)
+	}
+}
+
+func render(pkg string, root string) (string, error) {
+	var b strings.Builder
+
+	root = filepath.Clean(root)
+
+	b.WriteString("// Code generated by externs-gen; DO NOT EDIT.\n")
+	b.WriteString("package " + pkg + "\n\n")
+	b.WriteString("var Externs = []string{\n")
+
+	err := filepath.WalkDir(root, func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if d.IsDir() {
+			return nil
+		}
+
+		if filepath.Ext(path) != ".js" {
+			return nil
+		}
+
+		if filepath.Base(filepath.Dir(path)) != "externs" {
+			return nil
+		}
+
+		rel, err := filepath.Rel(root, path)
+		if err != nil {
+			return err
+		}
+
+		// Generated data should be slash-normalized even on Windows.
+		rel = filepath.ToSlash(rel)
+
+		fmt.Fprintf(&b, "\t%q,\n", rel)
+		return nil
+	})
+	if err != nil {
+		return "", err
+	}
+
+	b.WriteString("}\n")
+	return b.String(), nil
+}
+
+func fatal(err error) {
+	fmt.Fprintln(os.Stderr, "externs-gen:", err)
+	os.Exit(1)
+}