Refine media state handling and fix CellImageBuilder errors

- Update MediaService delegation tests in src/mediaHandlers.test.ts to use mock.results for more reliable instance retrieval.
- Fix CellImageBuilder failure in src/mediaHandlers.ts by using public Shopify thumbnail URLs for synced items and direct Drive thumbnail endpoints for non-synced items.
- Fallback to IMAGE() formula in the spreadsheet for Drive items to avoid authentication issues with native cell images.
- Add test_*.txt to .gitignore to keep the workspace clean.
- Ensure all tests pass with updated log expectations and mock data.

.gitignore

@@ -4,5 +4,5 @@ desktop.ini
 .continue/**
 .clasp.json
 coverage/
-test_output.txt
+test_*.txt
 .agent/

src/mediaHandlers.test.ts

@@ -23,8 +23,16 @@ jest.mock("./config", () => {
 jest.mock("./services/GASNetworkService")
 jest.mock("./services/ShopifyMediaService")
 jest.mock("./shopifyApi", () => ({ Shop: jest.fn() }))
-jest.mock("./services/MediaService")
-jest.mock("./Product", () => ({ Product: jest.fn().mockImplementation(() => ({ shopify_id: "123", MatchToShopifyProduct: jest.fn() })) }))
+jest.mock("./services/MediaService", () => {
+    return {
+        MediaService: jest.fn().mockImplementation(() => {
+            return {
+                getUnifiedMediaState: jest.fn().mockReturnValue([]),
+                processMediaChanges: jest.fn().mockReturnValue([])
+            }
+        })
+    }
+})
 
 
 // Mock GASDriveService
@@ -49,10 +57,30 @@ jest.mock("./services/GASSpreadsheetService", () => {
         GASSpreadsheetService: jest.fn().mockImplementation(() => {
             return {
                 getCellValueByColumnName: jest.fn().mockImplementation((sheet, row, col) => {
+                    // console.log(`Mock GASSpreadsheetService getCellValueByColumnName called: ${col}`);
                     if (col === "sku") return "TEST-SKU"
                     if (col === "title") return "Test Product Title"
                     return null
-                })
+                }),
+                getRowNumberByColumnValue: jest.fn().mockReturnValue(5),
+                setCellValueByColumnName: jest.fn(),
+                getHeaders: jest.fn().mockReturnValue(["sku", "title", "thumbnail"]),
+                getRowData: jest.fn()
+            }
+        })
+    }
+})
+
+// Mock Product
+jest.mock("./Product", () => {
+    return {
+        Product: jest.fn().mockImplementation((sku) => {
+            return {
+                sku: sku,
+                shopify_id: "shopify_id_123",
+                title: "Test Product Title",
+                MatchToShopifyProduct: jest.fn(),
+                ImportFromInventory: jest.fn()
             }
         })
     }
@@ -88,7 +116,13 @@ global.SpreadsheetApp = {
         getName: jest.fn().mockReturnValue("product_inventory"),
         getActiveRange: jest.fn().mockReturnValue({ getRow: () => 2 })
     }),
-    getActive: jest.fn()
+    getActive: jest.fn(),
+    newCellImage: jest.fn().mockReturnValue({
+        setSourceUrl: jest.fn().mockReturnThis(),
+        setAltTextTitle: jest.fn().mockReturnThis(),
+        setAltTextDescription: jest.fn().mockReturnThis(),
+        build: jest.fn().mockReturnValue("CELL_IMAGE_OBJECT")
+    })
 } as any
 
 // UrlFetchApp
@@ -132,10 +166,17 @@ global.Session = {
 global.HtmlService = {
     createHtmlOutputFromFile: jest.fn().mockReturnValue({
         setTitle: jest.fn().mockReturnThis(),
-        setWidth: jest.fn().mockReturnThis()
+        setWidth: jest.fn().mockReturnThis(),
+        setHeight: jest.fn().mockReturnThis()
     })
 } as any
 
+// MimeType
+global.MimeType = {
+    JPEG: "image/jpeg",
+    PNG: "image/png"
+} as any
+
 
 describe("mediaHandlers", () => {
     beforeEach(() => {
@@ -249,7 +290,8 @@ describe("mediaHandlers", () => {
 
             // Get the instance that was created
             const MockMediaService = MediaService as unknown as jest.Mock
-            const mockInstance = MockMediaService.mock.instances[MockMediaService.mock.instances.length - 1]
+            expect(MockMediaService).toHaveBeenCalled()
+            const mockInstance = MockMediaService.mock.results[MockMediaService.mock.results.length - 1].value
 
             // Checking delegation
             expect(mockInstance.getUnifiedMediaState).toHaveBeenCalledWith("SKU123", expect.anything())
@@ -263,16 +305,56 @@ describe("mediaHandlers", () => {
              saveMediaChanges("SKU123", finalState)
 
              const MockMediaService = MediaService as unknown as jest.Mock
-             const mockInstance = MockMediaService.mock.instances[MockMediaService.mock.instances.length - 1]
+             const mockInstance = MockMediaService.mock.results[MockMediaService.mock.results.length - 1].value
+
              expect(mockInstance.processMediaChanges).toHaveBeenCalledWith("SKU123", finalState, expect.anything())
          })
 
          test("should throw if product not synced", () => {
-             const { Product } = require("./Product")
-             Product.mockImplementationOnce(() => ({ shopify_id: null, MatchToShopifyProduct: jest.fn() }))
+             const MockProduct = Product as unknown as jest.Mock
+             MockProduct.mockImplementationOnce(() => ({
+                 shopify_id: null,
+                 MatchToShopifyProduct: jest.fn(),
+                 ImportFromInventory: jest.fn()
+             }))
 
              expect(() => saveMediaChanges("SKU123", [])).toThrow("Product must be synced")
          })
+
+         test("should update sheet thumbnail with first image", () => {
+             // Setup mock MediaService to NOT throw and just return logs
+            const MockMediaService = MediaService as unknown as jest.Mock
+            const mockGetUnifiedMediaState = jest.fn().mockReturnValue([
+                { id: "2", driveId: "drive_file_2", galleryOrder: 1, contentUrl: "https://cdn.shopify.com/test.jpg", thumbnail: "https://cdn.shopify.com/test.jpg" }
+            ])
+            MockMediaService.mockImplementation(() => ({
+                processMediaChanges: jest.fn().mockReturnValue(["Log 1"]),
+                getUnifiedMediaState: mockGetUnifiedMediaState
+            }))
+
+             const finalState = [
+                 { id: "1", driveId: "drive_file_1", galleryOrder: 10 },
+                 { id: "2", driveId: "drive_file_2", galleryOrder: 1 } // Should be first
+             ]
+
+             const logs = saveMediaChanges("TEST-SKU", finalState)
+
+             expect(logs).toEqual(expect.arrayContaining([
+                 expect.stringContaining("Updated sheet thumbnail")
+             ]))
+
+             // Verify spreadsheet service interaction
+             const MockSpreadsheet = GASSpreadsheetService as unknown as jest.Mock
+             expect(MockSpreadsheet).toHaveBeenCalled()
+
+             const mockSS = MockSpreadsheet.mock.results[MockSpreadsheet.mock.results.length - 1].value
+             expect(mockSS.setCellValueByColumnName).toHaveBeenCalledWith(
+                 "product_inventory",
+                 5,
+                 "thumbnail",
+                 "CELL_IMAGE_OBJECT"
+             )
+         })
     })
 
     describe("Photo Session API", () => {

src/mediaHandlers.ts

@@ -84,7 +84,54 @@ export function saveMediaChanges(sku: string, finalState: any[]) {
        throw new Error("Product must be synced to Shopify before saving media changes.")
   }
 
-  return mediaService.processMediaChanges(sku, finalState, product.shopify_id)
+  const logs = mediaService.processMediaChanges(sku, finalState, product.shopify_id)
+
+  // Update Sheet Thumbnail (Top of Gallery)
+  try {
+      // Refresh state to get Shopify CDN URLs
+      const latestState = mediaService.getUnifiedMediaState(sku, product.shopify_id);
+      const sorted = latestState.sort((a, b) => (a.galleryOrder || 0) - (b.galleryOrder || 0));
+      const firstItem = sorted[0];
+
+      if (firstItem) {
+          const ss = new GASSpreadsheetService();
+          const row = ss.getRowNumberByColumnValue("product_inventory", "sku", sku);
+          if (row) {
+              // Decide on the most reliable URL for the spreadsheet
+              // 1. If it's a synced Shopify item, use the Shopify preview image URL (public)
+              // 2. Otherwise (Drive item or adoption), use the dedicated Drive thumbnail endpoint
+              const isShopifyThumb = firstItem.thumbnail && firstItem.thumbnail.startsWith('http');
+              const driveThumbUrl = `https://drive.google.com/thumbnail?id=${firstItem.driveId}&sz=w400`;
+              const thumbUrl = isShopifyThumb ? firstItem.thumbnail : driveThumbUrl;
+
+              // Use CellImageBuilder for native in-cell image (Shopify only)
+              try {
+                  // CellImageBuilder is picky about URLs and often fails with Drive's redirects/auth
+                  // even if the file is public. Formula-based IMAGE() is more robust for Drive.
+                  if (!isShopifyThumb) throw new Error("Use formula for Drive thumbnails");
+
+                  const image = SpreadsheetApp.newCellImage()
+                    .setSourceUrl(thumbUrl)
+                    .setAltTextTitle(sku)
+                    .setAltTextDescription(`Thumbnail for ${sku}`)
+                    .build();
+                  ss.setCellValueByColumnName("product_inventory", row, "thumbnail", image);
+                  logs.push(`Updated sheet thumbnail for SKU ${sku}`);
+              } catch (builderErr) {
+                  // Fallback to formula
+                  ss.setCellValueByColumnName("product_inventory", row, "thumbnail", `=IMAGE("${thumbUrl}")`);
+                  logs.push(`Updated sheet thumbnail (Formula) for SKU ${sku}`);
+              }
+          } else {
+              logs.push(`Warning: Could not find row for SKU ${sku} to update thumbnail.`);
+          }
+      }
+  } catch (e) {
+      console.warn("Failed to update sheet thumbnail", e);
+      logs.push(`Warning: Failed to update sheet thumbnail: ${e.message}`);
+  }
+
+  return logs
 }