Review round 1 for the Node build module: registry for other @novox packages and refused bundles (1489), toolchain.reported stream (1483, 1488), re-pin to mesh-sdk 36d6f774; delta part 4 of 4

modules/mesh-build-node/cmd/mesh-build-node/workspace.go

@@ -60,6 +60,9 @@ func (m *Module) esbuild() string {
 
 // provide copies the toolchain's packages to <root>/node_modules unless they are there.
 func (m *Module) provide(root string) error {
+	if err := m.writeBin(filepath.Join(root, "bin")); err != nil {
+		return err
+	}
 	dest := filepath.Join(root, "node_modules")
 	if _, err := os.Stat(dest); err == nil {
 		return nil
@@ -67,6 +70,52 @@ func (m *Module) provide(root string) error {
 	return copyPackages(filepath.Join(m.toolchainDir(), "node_modules"), dest)
 }
 
+// binDir is the workspace's bin directory: small shell scripts, files and not links, that call the toolchain's tsc and
+// esbuild, so a package's scripts (`tsc`, `esbuild` by name) find them. npm ci runs with --no-bin-links, which leaves
+// the toolchain no .bin directory of its own.
+func binDir(root string) string { return filepath.Join(root, "bin") }
+
+func (m *Module) writeBin(dir string) error {
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		return err
+	}
+	for name, body := range map[string]string{
+		"tsc":     "exec node '" + m.tsc() + "' \"$@\"\n",
+		"esbuild": "exec '" + m.esbuild() + "' \"$@\"\n",
+	} {
+		path := filepath.Join(dir, name)
+		if err := os.WriteFile(path, []byte("#!/bin/sh\n"+body), 0o755); err != nil {
+			return err
+		}
+		if err := os.Chmod(path, 0o755); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// copyTree copies a directory of regular files and directories, keeping permission bits, except a build's output and
+// the repository's own .git. Anything else in it (a link) is an error: the mesh makes no symlink.
+func copyTree(from, to string) error {
+	return filepath.WalkDir(from, func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		rel, _ := filepath.Rel(from, path)
+		if d.IsDir() && (rel == ".mesh-build" || rel == ".git") {
+			return filepath.SkipDir
+		}
+		switch {
+		case d.IsDir():
+			return os.MkdirAll(filepath.Join(to, rel), 0o755)
+		case d.Type().IsRegular():
+			return copyFile(path, filepath.Join(to, rel))
+		default:
+			return fmt.Errorf("%s is neither a file nor a directory, and the build copies only those", path)
+		}
+	})
+}
+
 // copyPackages copies the packages of a node_modules directory except the toolchain's own tools. It copies regular
 // files and directories only and keeps their permission bits; anything else in the source is an error.
 func copyPackages(from, to string) error {