fix: implement chunked request handling for cloudflare vite dev-fs plugin

Reworked the dev-fs plugin to handle chunked write requests efficiently. Added mechanisms to track, process, and validate chunks, ensuring reliable file writes even for large data. Enhanced verbose logging for better debugging.

app/src/adapter/cloudflare/vite.ts

@@ -25,46 +25,156 @@ export function devFsVitePlugin({
       },
       configureServer(server) {
          if (!isDev) {
+            verbose && console.debug("[dev-fs-plugin] Not in dev mode, skipping");
             return;
          }
 
+         // Track active chunked requests
+         const activeRequests = new Map<
+            string,
+            {
+               totalChunks: number;
+               filename: string;
+               chunks: string[];
+               receivedChunks: number;
+            }
+         >();
+
          // Intercept stdout to watch for our write requests
          const originalStdoutWrite = process.stdout.write;
          process.stdout.write = function (chunk: any, encoding?: any, callback?: any) {
             const output = chunk.toString();
 
-            // Check if this output contains our special write request
-            if (output.includes("{{DEV_FS_WRITE_REQUEST}}")) {
-               try {
-                  // Extract the JSON from the log line
-                  const match = output.match(/{{DEV_FS_WRITE_REQUEST}} ({.*})/);
-                  if (match) {
-                     const writeRequest = JSON.parse(match[1]);
-                     if (writeRequest.type === "DEV_FS_WRITE_REQUEST") {
-                        if (verbose) {
-                           console.debug("[dev-fs-plugin] Intercepted write request via stdout");
-                        }
+            // Skip our own debug output
+            if (output.includes("[dev-fs-plugin]") || output.includes("[dev-fs-polyfill]")) {
+               // @ts-ignore
+               // biome-ignore lint/style/noArguments: <explanation>
+               return originalStdoutWrite.apply(process.stdout, arguments);
+            }
 
-                        // Process the write request immediately
-                        (async () => {
-                           try {
-                              const fullPath = resolve(projectRoot, writeRequest.filename);
-                              await nodeWriteFile(fullPath, writeRequest.data);
-                              if (verbose) {
-                                 console.debug("[dev-fs-plugin] File written successfully!");
-                              }
-                           } catch (error) {
-                              console.error("[dev-fs-plugin] Error writing file:", error);
-                           }
-                        })();
+            // Track if we process any protocol messages (to suppress output)
+            let processedProtocolMessage = false;
 
-                        // Don't output the raw write request to console
-                        return true;
+            // Process all start markers in this output
+            if (output.includes("{{DEV_FS_START}}")) {
+               const startMatches = [
+                  ...output.matchAll(/{{DEV_FS_START}} ([a-z0-9]+) (\d+) (.+)/g),
+               ];
+               for (const startMatch of startMatches) {
+                  const requestId = startMatch[1];
+                  const totalChunks = Number.parseInt(startMatch[2]);
+                  const filename = startMatch[3];
+
+                  activeRequests.set(requestId, {
+                     totalChunks,
+                     filename,
+                     chunks: new Array(totalChunks),
+                     receivedChunks: 0,
+                  });
+
+                  verbose &&
+                     console.debug(
+                        `[dev-fs-plugin] Started request ${requestId} for ${filename} (${totalChunks} chunks)`,
+                     );
+               }
+               processedProtocolMessage = true;
+            }
+
+            // Process all chunk data in this output
+            if (output.includes("{{DEV_FS_CHUNK}}")) {
+               const chunkMatches = [
+                  ...output.matchAll(/{{DEV_FS_CHUNK}} ([a-z0-9]+) (\d+) ([A-Za-z0-9+/=]+)/g),
+               ];
+               for (const chunkMatch of chunkMatches) {
+                  const requestId = chunkMatch[1];
+                  const chunkIndex = Number.parseInt(chunkMatch[2]);
+                  const chunkData = chunkMatch[3];
+
+                  const request = activeRequests.get(requestId);
+                  if (request) {
+                     request.chunks[chunkIndex] = chunkData;
+                     request.receivedChunks++;
+                     verbose &&
+                        console.debug(
+                           `[dev-fs-plugin] Received chunk ${chunkIndex}/${request.totalChunks - 1} for ${request.filename} (length: ${chunkData.length})`,
+                        );
+
+                     // Validate base64 chunk
+                     if (chunkData.length < 1000 && chunkIndex < request.totalChunks - 1) {
+                        verbose &&
+                           console.warn(
+                              `[dev-fs-plugin] WARNING: Chunk ${chunkIndex} seems truncated (length: ${chunkData.length})`,
+                           );
                      }
                   }
-               } catch (error) {
-                  // Not a valid write request, continue with normal output
                }
+               processedProtocolMessage = true;
+            }
+
+            // Process all end markers in this output
+            if (output.includes("{{DEV_FS_END}}")) {
+               const endMatches = [...output.matchAll(/{{DEV_FS_END}} ([a-z0-9]+)/g)];
+               for (const endMatch of endMatches) {
+                  const requestId = endMatch[1];
+                  const request = activeRequests.get(requestId);
+
+                  if (request && request.receivedChunks === request.totalChunks) {
+                     try {
+                        // Reconstruct the base64 string
+                        const fullBase64 = request.chunks.join("");
+                        verbose &&
+                           console.debug(
+                              `[dev-fs-plugin] Reconstructed ${request.filename} - base64 length: ${fullBase64.length}`,
+                           );
+
+                        // Decode and parse
+                        const decodedJson = atob(fullBase64);
+                        const writeRequest = JSON.parse(decodedJson);
+
+                        if (writeRequest.type === "DEV_FS_WRITE_REQUEST") {
+                           verbose &&
+                              console.debug(
+                                 `[dev-fs-plugin] Processing write request for ${writeRequest.filename}`,
+                              );
+
+                           // Process the write request
+                           (async () => {
+                              try {
+                                 const fullPath = resolve(projectRoot, writeRequest.filename);
+                                 verbose &&
+                                    console.debug(`[dev-fs-plugin] Writing to: ${fullPath}`);
+                                 await nodeWriteFile(fullPath, writeRequest.data);
+                                 verbose &&
+                                    console.debug("[dev-fs-plugin] File written successfully!");
+                              } catch (error) {
+                                 console.error("[dev-fs-plugin] Error writing file:", error);
+                              }
+                           })();
+
+                           // Clean up
+                           activeRequests.delete(requestId);
+                           return true;
+                        }
+                     } catch (error) {
+                        console.error(
+                           "[dev-fs-plugin] Error processing chunked request:",
+                           String(error),
+                        );
+                        activeRequests.delete(requestId);
+                     }
+                  } else if (request) {
+                     verbose &&
+                        console.debug(
+                           `[dev-fs-plugin] Request ${requestId} incomplete: ${request.receivedChunks}/${request.totalChunks} chunks`,
+                        );
+                  }
+               }
+               processedProtocolMessage = true;
+            }
+
+            // If we processed any protocol messages, suppress output
+            if (processedProtocolMessage) {
+               return callback ? callback() : true;
             }
 
             // @ts-ignore
@@ -97,7 +207,7 @@ export function devFsVitePlugin({
 if (typeof globalThis !== 'undefined') {
   globalThis.__devFsPolyfill = {
     writeFile: async (filename, data) => {
-      ${verbose ? "console.debug('dev-fs polyfill: Intercepting write request for', filename);" : ""}
+      ${verbose ? "console.debug('[dev-fs-polyfill] Intercepting write request for', filename);" : ""}
       
       // Use console logging as a communication channel
       // The main process will watch for this specific log pattern
@@ -108,16 +218,38 @@ if (typeof globalThis !== 'undefined') {
         timestamp: Date.now()
       };
       
-      // Output as a specially formatted console message
-      console.log('{{DEV_FS_WRITE_REQUEST}}', JSON.stringify(writeRequest));
-      ${verbose ? "console.debug('dev-fs polyfill: Write request sent via console');" : ""}
+      // Output as a specially formatted console message with end delimiter
+      // Base64 encode the JSON to avoid any control character issues
+      const jsonString = JSON.stringify(writeRequest);
+      const encodedJson = btoa(jsonString);
+      
+      // Split into reasonable chunks that balance performance vs reliability  
+      const chunkSize = 2000; // 2KB chunks - safe for most environments
+      const chunks = [];
+      for (let i = 0; i < encodedJson.length; i += chunkSize) {
+        chunks.push(encodedJson.slice(i, i + chunkSize));
+      }
+      
+      const requestId = Date.now().toString(36) + Math.random().toString(36).substr(2, 5);
+      
+      // Send start marker (use stdout.write to avoid console display)
+      process.stdout.write('{{DEV_FS_START}} ' + requestId + ' ' + chunks.length + ' ' + filename + '\\n');
+      
+      // Send each chunk
+      chunks.forEach((chunk, index) => {
+        process.stdout.write('{{DEV_FS_CHUNK}} ' + requestId + ' ' + index + ' ' + chunk + '\\n');
+      });
+      
+      // Send end marker
+      process.stdout.write('{{DEV_FS_END}} ' + requestId + '\\n');
       
       return Promise.resolve();
     }
   };
-}
-`;
+}`;
             return polyfill + code;
+         } else {
+            verbose && console.debug("[dev-fs-plugin] Not transforming", id);
          }
       },
    } satisfies Plugin;