diff --git a/test/core/Persistence.test.js b/test/core/Persistence.test.js
index c332beb..fdf0c2e 100644
--- a/test/core/Persistence.test.js
+++ b/test/core/Persistence.test.js
@@ -32,7 +32,12 @@ describe("Core: Persistence", () => {
       transaction: sinon.stub().returns(mockTransaction),
     };
 
-    // Mock indexedDB.open
+    // Use window or self for browser environment
+    globalObj = typeof window !== 'undefined' ? window : (typeof self !== 'undefined' ? self : globalThis);
+  });
+
+  const createMockRequest = () => {
+    // Mock indexedDB.open - create a new request each time
     mockRequest = {
       onerror: null,
       onsuccess: null,
@@ -40,30 +45,35 @@ describe("Core: Persistence", () => {
       result: mockDB,
     };
 
-    // Use window or self for browser environment
-    globalObj = typeof window !== 'undefined' ? window : (typeof self !== 'undefined' ? self : globalThis);
-    globalObj.indexedDB = {
-      open: sinon.stub().returns(mockRequest),
-    };
-  });
+    // Mock indexedDB using defineProperty since it's read-only
+    Object.defineProperty(globalObj, 'indexedDB', {
+      value: {
+        open: sinon.stub().returns(mockRequest),
+      },
+      writable: true,
+      configurable: true,
+    });
 
-  const triggerSuccess = () => {
-    if (mockRequest.onsuccess) {
-      mockRequest.onsuccess({ target: { result: mockDB } });
-    }
-  };
-
-  const triggerUpgrade = () => {
-    if (mockRequest.onupgradeneeded) {
-      mockRequest.onupgradeneeded({ target: { result: mockDB } });
-    }
+    return mockRequest;
   };
 
   it("CoA 1: init should create database and object stores", async () => {
-    triggerUpgrade();
-    triggerSuccess();
+    const request = createMockRequest();
+    
+    // Start init, which will call indexedDB.open
+    const initPromise = persistence.init();
+    
+    // Trigger upgrade first (happens synchronously during open)
+    if (request.onupgradeneeded) {
+      request.onupgradeneeded({ target: { result: mockDB } });
+    }
+    
+    // Then trigger success
+    if (request.onsuccess) {
+      request.onsuccess({ target: { result: mockDB } });
+    }
 
-    await persistence.init();
+    await initPromise;
 
     expect(globalObj.indexedDB.open.calledWith("AetherShardsDB", 2)).to.be.true;
     expect(mockDB.createObjectStore.calledWith("Runs", { keyPath: "id" })).to.be.true;
@@ -194,17 +204,28 @@ describe("Core: Persistence", () => {
   });
 
   it("CoA 8: saveRun should auto-init if db not initialized", async () => {
-    triggerUpgrade();
-    triggerSuccess();
-
+    const request = createMockRequest();
+    
     const runData = { seed: 12345 };
     const mockPutRequest = {
-      onsuccess: null,
+      onsuccess: sinon.stub(),
       onerror: null,
     };
     mockStore.put.returns(mockPutRequest);
 
+    // Start saveRun, which will trigger init
     const savePromise = persistence.saveRun(runData);
+    
+    // Trigger upgrade and success for init
+    if (request.onupgradeneeded) {
+      request.onupgradeneeded({ target: { result: mockDB } });
+    }
+    if (request.onsuccess) {
+      request.onsuccess({ target: { result: mockDB } });
+    }
+    
+    // Wait a bit for init to complete, then trigger put success
+    await new Promise(resolve => setTimeout(resolve, 10));
     mockPutRequest.onsuccess();
 
     await savePromise;
diff --git a/test/generation/PostProcessing.test.js b/test/generation/PostProcessing.test.js
index f13cb74..6ca5199 100644
--- a/test/generation/PostProcessing.test.js
+++ b/test/generation/PostProcessing.test.js
@@ -82,6 +82,9 @@ describe("Generation: PostProcessor", () => {
   });
 
   it("CoA 4: floodFill should not include disconnected tiles", () => {
+    // Fill entire grid with solid first to isolate regions
+    grid.fill(1);
+    
     // Create two separate regions with proper floor setup
     // Region 1: connected tiles
     grid.setCell(1, 0, 1, 1); // Floor
@@ -89,7 +92,7 @@ describe("Generation: PostProcessor", () => {
     grid.setCell(2, 0, 1, 1); // Floor
     grid.setCell(2, 1, 1, 0); // Air (connected)
 
-    // Region 2: disconnected (no floor connection)
+    // Region 2: disconnected (surrounded by solid, no path to region 1)
     grid.setCell(10, 0, 10, 1); // Floor
     grid.setCell(10, 1, 10, 0); // Air (disconnected)