Reject nonregular configuration files before opening them

source_fifo_test.go

@@ -0,0 +1,71 @@
+//go:build darwin || linux
+
+package configkit
+
+import (
+	"context"
+	"errors"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"syscall"
+	"testing"
+	"time"
+)
+
+func TestNonregularSourcesDoNotBlock(t *testing.T) {
+	if mode := os.Getenv("CONFIGKIT_FIFO_TEST_MODE"); mode != "" {
+		root := os.Getenv("CONFIGKIT_FIFO_TEST_ROOT")
+		source := File(filepath.Join(root, "config.yml"))
+		opts := Options[map[string]any]{}
+		switch mode {
+		case "file":
+			source = File(filepath.Join(root, "pipe.yml"))
+		case "import":
+			opts.Imports = true
+		case "profile":
+			opts.Profile = "fifo"
+		}
+		_, err := Load(source, opts)
+		var loadErr *LoadError
+		if !errors.As(err, &loadErr) {
+			t.Fatalf("expected safe load error, got %v", err)
+		}
+		for _, d := range loadErr.Diagnostics() {
+			if d.Code == CodeSourceNotRegular {
+				return
+			}
+		}
+		t.Fatalf("expected nonregular classification, got %v", loadErr.Diagnostics())
+	}
+	for _, mode := range []string{"file", "import", "profile"} {
+		t.Run(mode, func(t *testing.T) {
+			root := t.TempDir()
+			input := "value: 1\n"
+			if mode == "import" {
+				input = "_configkit:\n  imports:\n    - path: pipe.yml\n"
+			}
+			if err := os.WriteFile(filepath.Join(root, "config.yml"), []byte(input), 0600); err != nil {
+				t.Fatal(err)
+			}
+			if err := os.Mkdir(filepath.Join(root, "profiles"), 0700); err != nil {
+				t.Fatal(err)
+			}
+			fifo := filepath.Join(root, "pipe.yml")
+			if mode == "profile" {
+				fifo = filepath.Join(root, "profiles", "fifo.yml")
+			}
+			if err := syscall.Mkfifo(fifo, 0600); err != nil {
+				t.Fatal(err)
+			}
+			ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+			defer cancel()
+			cmd := exec.CommandContext(ctx, os.Args[0], "-test.run=^TestNonregularSourcesDoNotBlock$")
+			cmd.Env = append(os.Environ(), "CONFIGKIT_FIFO_TEST_MODE="+mode, "CONFIGKIT_FIFO_TEST_ROOT="+root)
+			out, err := cmd.CombinedOutput()
+			if err != nil {
+				t.Fatalf("FIFO load failed or blocked: %v, %s", err, out)
+			}
+		})
+	}
+}