test(sdk/auth): assert priority survives partial-metadata save

Covers the headline of the preceding fix: an existing priority value on
disk must be preserved when an update payload omits it.

Author: drwpls

sdk/auth/filestore_disabled_test.go

@@ -111,3 +111,45 @@ func TestFileTokenStore_Save_MergesPartialMetadataWithExistingAuthFile(t *testin
 		t.Fatalf("name=%#v, want codex.json (raw=%s)", got, string(raw))
 	}
 }
+
+func TestFileTokenStore_Save_PreservesExistingPriorityWhenAbsentFromUpdate(t *testing.T) {
+	ctx := context.Background()
+	baseDir := t.TempDir()
+	path := filepath.Join(baseDir, "codex.json")
+
+	// The on-disk file carries a priority the update payload does not include;
+	// saving partial metadata must not drop it.
+	seed := `{"type":"codex","access_token":"access","priority":7}`
+	if err := os.WriteFile(path, []byte(seed), 0o600); err != nil {
+		t.Fatalf("seed auth file: %v", err)
+	}
+
+	store := NewFileTokenStore()
+	store.SetBaseDir(baseDir)
+	auth := &cliproxyauth.Auth{
+		ID:       "codex.json",
+		Provider: "codex",
+		FileName: "codex.json",
+		Metadata: map[string]any{"name": "codex.json"},
+	}
+
+	if _, err := store.Save(ctx, auth); err != nil {
+		t.Fatalf("Save() error: %v", err)
+	}
+
+	raw, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("read auth file: %v", err)
+	}
+	var meta map[string]any
+	if err := json.Unmarshal(raw, &meta); err != nil {
+		t.Fatalf("unmarshal auth file: %v", err)
+	}
+	// JSON numbers decode to float64.
+	if got, _ := meta["priority"].(float64); got != 7 {
+		t.Fatalf("priority=%#v, want preserved 7 (raw=%s)", meta["priority"], string(raw))
+	}
+	if got := meta["access_token"]; got != "access" {
+		t.Fatalf("access_token=%#v, want preserved access (raw=%s)", got, string(raw))
+	}
+}