fix: Editor preloading survives blocked asset downloads

ios/Sources/GutenbergKit/Sources/Stores/EditorAssetLibrary.swift

@@ -130,16 +130,22 @@ public actor EditorAssetLibrary {
         let editorRepresentation = try manifest.buildEditorRepresentation(for: self.configuration)
         try bundle.writeManifest(editorRepresentation: editorRepresentation)
 
-        try await withThrowingTaskGroup { group in
+        await withTaskGroup { group in
             let links = (manifest.scripts + manifest.styles).filter { self.isSupportedAsset($0) }
-            
+
             for asset in links {
                 group.addTask {
-                    (asset, try await self.fetchAsset(url: asset, into: bundle))
+                    do {
+                        try await self.fetchAsset(url: asset, into: bundle)
+                    } catch {
+                        // Log and continue - individual asset failures shouldn't block the editor
+                        // This handles cases like content blockers blocking analytics scripts
+                        log(.warn, "Failed to download asset \(asset.lastPathComponent): \(error.localizedDescription)")
+                    }
                 }
             }
-            
-            for try await _ in group {
+
+            for await _ in group {
                 complete += 1
                 await progress?(EditorProgress(completed: complete, total: links.count))
             }
@@ -150,14 +156,15 @@ public actor EditorAssetLibrary {
 
     /// Downloads a single asset and copies it into the temporary bundle directory.
     ///
+    @discardableResult
     private func fetchAsset(url: URL, into bundle: EditorAssetBundle) async throws -> URL {
         let tempUrl = try await logExecutionTime("Downloading \(url.lastPathComponent)") {
             try await httpClient.download(URLRequest(method: .GET, url: url)).0
         }
 
         let destinationPath = bundle.bundleRoot.appending(path: url.path(percentEncoded: false))
         let destinationParent = destinationPath.deletingLastPathComponent()
-        
+
         // Ensure the destination directory exists
         try FileManager.default.createDirectory(at: destinationParent, withIntermediateDirectories: true)
 

ios/Tests/GutenbergKitTests/Stores/EditorAssetLibraryTests.swift

@@ -676,7 +676,12 @@ struct EditorAssetLibraryTests {
       """
 
         let mockClient = EditorAssetLibraryMockHTTPClient()
-        mockClient.urlResponseHandler = { _ in Data(manifestJSON.utf8) }
+        mockClient.urlResponseHandler = { url in
+            if url.path.contains("editor-assets") {
+                return Data(manifestJSON.utf8)
+            }
+            return Data("mock content".utf8)
+        }
 
         let library = makeLibrary(httpClient: mockClient, cachePolicy: .ignore)
 
@@ -769,7 +774,12 @@ struct EditorAssetLibraryTests {
       """
 
         let mockClient = EditorAssetLibraryMockHTTPClient()
-        mockClient.urlResponseHandler = { _ in Data(manifestJSON.utf8) }
+        mockClient.urlResponseHandler = { url in
+            if url.path.contains("editor-assets") {
+                return Data(manifestJSON.utf8)
+            }
+            return Data("mock content".utf8)
+        }
 
         let library = makeLibrary(httpClient: mockClient, cachePolicy: .ignore)
 
@@ -816,6 +826,53 @@ struct EditorAssetLibraryTests {
         #expect(progressTracker.count == 1)
         #expect(progressTracker.updates.first?.total == 1)
     }
+
+    @Test("buildBundle continues when individual asset downloads fail")
+    func buildBundleContinuesWhenAssetDownloadsFail() async throws {
+        let manifestJSON = """
+      {
+          "scripts": "<script src=\\"https://example.com/good-script.js\\"></script><script src=\\"https://blocked.com/stats.js\\"></script>",
+          "styles": "<link rel=\\"stylesheet\\" href=\\"https://example.com/style.css\\">",
+          "allowed_block_types": ["core/paragraph"]
+      }
+      """
+
+        let mockClient = EditorAssetLibraryMockHTTPClient()
+        mockClient.urlResponseHandler = { url in
+            if url.path.contains("editor-assets") {
+                return Data(manifestJSON.utf8)
+            }
+            // Simulate content blocker blocking stats.js
+            if url.host == "blocked.com" {
+                throw URLError(.badURL)
+            }
+            return Data("mock content".utf8)
+        }
+
+        let library = makeLibrary(httpClient: mockClient, cachePolicy: .ignore)
+
+        let manifest = try await library.fetchManifest()
+
+        // Should NOT throw - individual asset failures are caught and logged
+        let bundle = try await library.buildBundle(for: manifest)
+
+        // Bundle should be created successfully
+        #expect(!bundle.id.isEmpty)
+
+        // Verify progress was reported for all assets (including the failed one)
+        #expect(mockClient.downloadCallCount == 3)
+
+        // Verify the successful assets were downloaded
+        let bundleRoot = await library.bundleRoot(for: bundle)
+        let goodScriptPath = bundleRoot.appending(path: "/good-script.js")
+        let stylePath = bundleRoot.appending(path: "/style.css")
+        #expect(FileManager.default.fileExists(at: goodScriptPath))
+        #expect(FileManager.default.fileExists(at: stylePath))
+
+        // The failed asset should not exist
+        let failedScriptPath = bundleRoot.appending(path: "/stats.js")
+        #expect(!FileManager.default.fileExists(at: failedScriptPath))
+    }
 }
 
 // MARK: - Progress Tracker for Tests
@@ -844,8 +901,6 @@ final class EditorAssetLibraryMockHTTPClient: EditorHTTPClientProtocol, @uncheck
     var getCallCount = 0
     var downloadCallCount = 0
     var downloadedURLs: [URL] = []
-    var downloadResponse: URL?
-    var shouldThrowError: Error?
     private let lock = NSLock()
 
     /// URLs requested via `perform(_:)`. Use this to verify which endpoints were called.
@@ -854,8 +909,10 @@ final class EditorAssetLibraryMockHTTPClient: EditorHTTPClientProtocol, @uncheck
         lock.withLock { _requestedURLs }
     }
 
-    /// Handler for generating response data based on request URL. Defaults to returning empty data.
-    var urlResponseHandler: ((URL) -> Data) = { _ in Data() }
+    /// Handler for generating response data based on request URL.
+    /// Can throw to simulate failures for specific URLs.
+    /// Used by both `perform()` and `download()` methods.
+    var urlResponseHandler: ((URL) throws -> Data) = { _ in Data() }
 
     func perform(_ urlRequest: URLRequest) async throws -> (Data, HTTPURLResponse) {
         let url = try #require(urlRequest.url)
@@ -865,11 +922,7 @@ final class EditorAssetLibraryMockHTTPClient: EditorHTTPClientProtocol, @uncheck
             _requestedURLs.append(url)
         }
 
-        if let error = shouldThrowError {
-            throw error
-        }
-
-        let responseData = urlResponseHandler(url)
+        let responseData = try urlResponseHandler(url)
 
         let response = HTTPURLResponse(
             url: url,
@@ -889,9 +942,10 @@ final class EditorAssetLibraryMockHTTPClient: EditorHTTPClientProtocol, @uncheck
             downloadedURLs.append(url)
         }
 
-        if let error = shouldThrowError {
-            throw error
-        }
+        let data = try urlResponseHandler(url)
+
+        let tempURL = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
+        try data.write(to: tempURL)
 
         let response = HTTPURLResponse(
             url: url,
@@ -900,16 +954,6 @@ final class EditorAssetLibraryMockHTTPClient: EditorHTTPClientProtocol, @uncheck
             headerFields: nil
         )!
 
-        // Create a temporary file with some content
-        let tempURL =
-        downloadResponse
-        ?? FileManager.default.temporaryDirectory
-            .appendingPathComponent(UUID().uuidString)
-
-        if downloadResponse == nil {
-            try Data("mock content".utf8).write(to: tempURL)
-        }
-
         return (tempURL, response)
     }
 }