add users logic

users/internal/auth/password_test.go

@@ -0,0 +1,30 @@
+package auth
+
+import "testing"
+
+func TestHashAndCompare(t *testing.T) {
+	h := NewHasher(0) // default cost
+
+	hash, err := h.Hash("correct horse battery staple")
+	if err != nil {
+		t.Fatalf("hash: %v", err)
+	}
+	if hash == "correct horse battery staple" {
+		t.Fatal("hash must not equal the plaintext")
+	}
+	if err := h.Compare(hash, "correct horse battery staple"); err != nil {
+		t.Errorf("correct password rejected: %v", err)
+	}
+	if err := h.Compare(hash, "wrong password"); err == nil {
+		t.Error("wrong password accepted")
+	}
+}
+
+func TestHashSaltsEachTime(t *testing.T) {
+	h := NewHasher(0)
+	a, _ := h.Hash("same")
+	b, _ := h.Hash("same")
+	if a == b {
+		t.Error("two hashes of the same password must differ (random salt)")
+	}
+}