restructure project, add claudemd

go/cmd/typecheck/main.go

@@ -0,0 +1,150 @@
+package main
+
+// Frontend TypeScript checker. Runs tsc in noEmit mode using
+// tsconfig.json. Requires node on PATH; downloads the pinned TypeScript
+// release on first run (no npm).
+//
+//   go run ./cmd/typecheck
+//   go run ./cmd/typecheck -p tsconfig.json
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"flag"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+)
+
+const typescriptVersion = "5.8.3"
+
+func main() {
+	tsconfig := flag.String("p", "tsconfig.json", "path to tsconfig.json")
+	flag.Parse()
+
+	if err := runTypecheck(*tsconfig); err != nil {
+		fmt.Fprintf(os.Stderr, "Typecheck failed: %v\n", err)
+		os.Exit(1)
+	}
+}
+
+func runTypecheck(tsconfig string) error {
+	node, err := exec.LookPath("node")
+	if err != nil {
+		return fmt.Errorf("node not found on PATH (required to run tsc): %w", err)
+	}
+
+	tsc, err := ensureTypeScript()
+	if err != nil {
+		return err
+	}
+
+	if _, err := os.Stat(tsconfig); err != nil {
+		return fmt.Errorf("tsconfig not found: %s", tsconfig)
+	}
+
+	fmt.Printf("Typechecking with TypeScript %s...\n", typescriptVersion)
+	cmd := exec.Command(node, tsc, "--noEmit", "-p", tsconfig)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	if err := cmd.Run(); err != nil {
+		return err
+	}
+
+	fmt.Println("No type errors.")
+	return nil
+}
+
+func ensureTypeScript() (string, error) {
+	root, err := os.Getwd()
+	if err != nil {
+		return "", err
+	}
+
+	cacheDir := filepath.Join(root, "tools", ".cache", "typescript", typescriptVersion)
+	tscPath := filepath.Join(cacheDir, "package", "lib", "tsc.js")
+	if _, err := os.Stat(tscPath); err == nil {
+		return tscPath, nil
+	}
+
+	fmt.Printf("Downloading TypeScript %s...\n", typescriptVersion)
+	if err := downloadTypeScript(cacheDir); err != nil {
+		return "", err
+	}
+
+	if _, err := os.Stat(tscPath); err != nil {
+		return "", fmt.Errorf("tsc not found after download: %s", tscPath)
+	}
+	return tscPath, nil
+}
+
+func downloadTypeScript(destDir string) error {
+	url := fmt.Sprintf("https://registry.npmjs.org/typescript/-/typescript-%s.tgz", typescriptVersion)
+	resp, err := http.Get(url)
+	if err != nil {
+		return fmt.Errorf("download typescript: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("download typescript: HTTP %s", resp.Status)
+	}
+
+	if err := os.MkdirAll(destDir, 0o755); err != nil {
+		return err
+	}
+	return extractTGZ(resp.Body, destDir)
+}
+
+func extractTGZ(r io.Reader, destDir string) error {
+	gz, err := gzip.NewReader(r)
+	if err != nil {
+		return fmt.Errorf("read typescript archive: %w", err)
+	}
+	defer gz.Close()
+
+	tr := tar.NewReader(gz)
+	cleanDest := filepath.Clean(destDir)
+
+	for {
+		hdr, err := tr.Next()
+		if err == io.EOF {
+			return nil
+		}
+		if err != nil {
+			return fmt.Errorf("read typescript archive: %w", err)
+		}
+
+		target := filepath.Join(destDir, filepath.FromSlash(hdr.Name))
+		cleanTarget := filepath.Clean(target)
+		if cleanTarget != cleanDest && !strings.HasPrefix(cleanTarget, cleanDest+string(os.PathSeparator)) {
+			return fmt.Errorf("invalid archive path: %s", hdr.Name)
+		}
+
+		switch hdr.Typeflag {
+		case tar.TypeDir:
+			if err := os.MkdirAll(target, 0o755); err != nil {
+				return err
+			}
+		case tar.TypeReg:
+			if err := os.MkdirAll(filepath.Dir(target), 0o755); err != nil {
+				return err
+			}
+			f, err := os.OpenFile(target, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, os.FileMode(hdr.Mode)&0o777|0o600)
+			if err != nil {
+				return err
+			}
+			if _, err := io.Copy(f, tr); err != nil {
+				f.Close()
+				return err
+			}
+			if err := f.Close(); err != nil {
+				return err
+			}
+		}
+	}
+}