Keep pod2html cache file out of the working directory

external.go

@@ -15,9 +15,9 @@ import (
 
 // limitedWriter wraps a writer and returns an error if the limit is exceeded.
 type limitedWriter struct {
-	w       io.Writer
-	n       int
-	limit   int
+	w     io.Writer
+	n     int
+	limit int
 }
 
 func (lw *limitedWriter) Write(p []byte) (int, error) {
@@ -34,7 +34,7 @@ type InputMode int
 
 const (
 	InputStdin    InputMode = iota // Pass content via stdin (default).
-	InputTempFile                  // Write to a temp file, replace {file} in args.
+	InputTempFile                  // Write to a temp file, replace {file} and {dir} in args.
 )
 
 const defaultTimeout = 30 * time.Second
@@ -45,7 +45,7 @@ const maxOutputSize = 2 * 1024 * 1024
 // ExternalConfig configures an external renderer.
 type ExternalConfig struct {
 	Command     string        // Command to execute.
-	Args        []string      // Arguments. Use {file} as a placeholder for temp file path.
+	Args        []string      // Arguments. {file} is the temp file path, {dir} a per-render scratch directory.
 	InputMode   InputMode     // How to pass content to the command.
 	Timeout     time.Duration // Command timeout. Zero means 30s default.
 	BodyPattern string        // Regex to extract body from full HTML output. Empty means use full output.
@@ -128,11 +128,16 @@ func (r *ExternalRenderer) renderWithTempFile(content []byte) (string, error) {
 		ext = "." + r.config.Command
 	}
 
-	f, err := os.CreateTemp("", "markup-*"+ext)
+	dir, err := os.MkdirTemp("", "markup-*")
+	if err != nil {
+		return "", err
+	}
+	defer func() { _ = os.RemoveAll(dir) }()
+
+	f, err := os.CreateTemp(dir, "markup-*"+ext)
 	if err != nil {
 		return "", err
 	}
-	defer func() { _ = os.Remove(f.Name()) }()
 
 	if _, err := f.Write(content); err != nil {
 		_ = f.Close()
@@ -142,7 +147,8 @@ func (r *ExternalRenderer) renderWithTempFile(content []byte) (string, error) {
 
 	args := make([]string, len(r.config.Args))
 	for i, arg := range r.config.Args {
-		args[i] = strings.ReplaceAll(arg, "{file}", f.Name())
+		arg = strings.ReplaceAll(arg, "{file}", f.Name())
+		args[i] = strings.ReplaceAll(arg, "{dir}", dir)
 	}
 
 	ctx, cancel := context.WithTimeout(context.Background(), r.timeout)
@@ -224,7 +230,7 @@ func rstRender(content []byte) (string, error) {
 
 // toolCache caches which external tools are available.
 var (
-	toolCache   sync.Map
+	toolCache sync.Map
 )
 
 func toolAvailable(name string) bool {

markup.go

@@ -137,9 +137,9 @@ func NewDefaultRegistry() *Registry {
 		".rst", ".rest")
 
 	r.Register(FormatPod, NewExternalRenderer(ExternalConfig{
-		Command:   "pod2html",
-		InputMode: InputTempFile,
-		Args:      []string{"--infile={file}", "--quiet"},
+		Command:     "pod2html",
+		InputMode:   InputTempFile,
+		Args:        []string{"--infile={file}", "--cachedir={dir}", "--quiet"},
 		BodyPattern: `(?s)<body[^>]*>\s*(.*?)\s*</body>`,
 	}), ".pod")
 

markup_test.go

@@ -520,6 +520,7 @@ func TestRenderPod(t *testing.T) {
 		t.Skip("pod2html not installed")
 	}
 	content := readTestdata(t, "README.pod")
+	t.Chdir(t.TempDir())
 	result, err := r.Render("README.pod", content)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
@@ -533,6 +534,13 @@ func TestRenderPod(t *testing.T) {
 	if strings.Contains(result.HTML, "<html") {
 		t.Errorf("expected body-only HTML, got full document")
 	}
+	entries, err := os.ReadDir(".")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(entries) != 0 {
+		t.Errorf("renderer created files: %v", entries)
+	}
 }
 
 func TestRenderTextile(t *testing.T) {
@@ -719,6 +727,23 @@ func TestExternalRendererBodyExtraction(t *testing.T) {
 	}
 }
 
+func TestExternalRendererTempFilePlaceholders(t *testing.T) {
+	r := NewExternalRenderer(ExternalConfig{
+		Command:   "sh",
+		Args:      []string{"-c", `test "$(dirname "$2")" = "$1" && cat "$2"`, "sh", "{dir}", "{file}"},
+		InputMode: InputTempFile,
+		TempExt:   ".txt",
+	})
+
+	html, err := r.Render([]byte("<p>hi</p>"))
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if html != "<p>hi</p>" {
+		t.Errorf("html = %q, want %q", html, "<p>hi</p>")
+	}
+}
+
 // --- RendererFunc ---
 
 func TestRendererFunc(t *testing.T) {