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pkg/idempotency/store_test.go

@@ -0,0 +1,106 @@
+package idempotency
+
+import (
+	"os"
+	"path/filepath"
+	"sync"
+	"testing"
+)
+
+func TestPutGet(t *testing.T) {
+	s, err := Open(filepath.Join(t.TempDir(), "idem.log"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer s.Close()
+
+	if _, ok := s.Get("a"); ok {
+		t.Fatal("unexpected hit on empty store")
+	}
+	if err := s.Put("a", 42); err != nil {
+		t.Fatal(err)
+	}
+	if id, ok := s.Get("a"); !ok || id != 42 {
+		t.Fatalf("Get(a) = %d,%v; want 42,true", id, ok)
+	}
+}
+
+func TestFirstWriterWins(t *testing.T) {
+	s, _ := Open(filepath.Join(t.TempDir(), "idem.log"))
+	defer s.Close()
+	_ = s.Put("a", 1)
+	_ = s.Put("a", 2) // ignored
+	if id, _ := s.Get("a"); id != 1 {
+		t.Fatalf("got %d, want first value 1", id)
+	}
+}
+
+func TestDurableAcrossReopen(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "idem.log")
+	s, _ := Open(path)
+	_ = s.Put("checkout-x", 1001)
+	_ = s.Put("checkout-y", 1002)
+	_ = s.Close()
+
+	// A fresh process (the restart case the in-memory map failed) must still see
+	// the recorded keys — this is the duplicate-order bug the durable store fixes.
+	s2, err := Open(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer s2.Close()
+	if id, ok := s2.Get("checkout-x"); !ok || id != 1001 {
+		t.Fatalf("after reopen Get(checkout-x) = %d,%v; want 1001,true", id, ok)
+	}
+	if id, ok := s2.Get("checkout-y"); !ok || id != 1002 {
+		t.Fatalf("after reopen Get(checkout-y) = %d,%v; want 1002,true", id, ok)
+	}
+}
+
+func TestCorruptTrailingLineSkipped(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "idem.log")
+	s, _ := Open(path)
+	_ = s.Put("good", 7)
+	_ = s.Close()
+
+	// Simulate a torn write from a crash mid-append.
+	f, _ := os.OpenFile(path, os.O_APPEND|os.O_WRONLY, 0o644)
+	_, _ = f.WriteString(`{"k":"bad","id":`)
+	_ = f.Close()
+
+	s2, err := Open(path)
+	if err != nil {
+		t.Fatalf("open with corrupt tail: %v", err)
+	}
+	defer s2.Close()
+	if id, ok := s2.Get("good"); !ok || id != 7 {
+		t.Fatalf("good key lost after corrupt tail: %d,%v", id, ok)
+	}
+	if _, ok := s2.Get("bad"); ok {
+		t.Fatal("corrupt line should not have loaded")
+	}
+}
+
+func TestLockSerialisesKey(t *testing.T) {
+	s, _ := Open(filepath.Join(t.TempDir(), "idem.log"))
+	defer s.Close()
+
+	// Two goroutines contend on the same key; the lock must serialise the
+	// check→create→record so exactly one writes and both agree on the value.
+	var wg sync.WaitGroup
+	for i := 0; i < 2; i++ {
+		wg.Add(1)
+		go func(v uint64) {
+			defer wg.Done()
+			unlock := s.Lock("k")
+			defer unlock()
+			if _, ok := s.Get("k"); !ok {
+				_ = s.Put("k", v)
+			}
+		}(uint64(i + 1))
+	}
+	wg.Wait()
+	if _, ok := s.Get("k"); !ok {
+		t.Fatal("expected a value recorded under contention")
+	}
+}