v0.2.2 fixes: split only text sources, report a mode change once, don't block on open

file_unix_test.go

@@ -0,0 +1,30 @@
+//go:build unix
+
+package config
+
+import (
+	"path/filepath"
+	"syscall"
+	"testing"
+	"time"
+)
+
+// The open cannot block: a FIFO swapped in after the Stat fails at once
+func TestOpenConfigNeverBlocks(t *testing.T) {
+	fifo := filepath.Join(t.TempDir(), "config.toml")
+	if err := syscall.Mkfifo(fifo, 0600); err != nil {
+		t.Skip(err)
+	}
+	done := make(chan struct{})
+	go func() {
+		if f, err := openConfig(fifo); err == nil {
+			f.Close()
+		}
+		close(done)
+	}()
+	select {
+	case <-done:
+	case <-time.After(2 * time.Second):
+		t.Fatal("open blocked on a FIFO without a writer")
+	}
+}