Enhance typings

src/Formidable.ts

@@ -35,7 +35,7 @@ const DEFAULT_OPTIONS: IFormidableOptions = {
   enabledPlugins: [octetstream, querystring, multipart, json],
   fileWriteStreamHandler: null,
   defaultInvalidName: 'invalid-name',
-  filter(_part) {
+  filter(_part: IPart) {
     return true;
   },
   filename: undefined,
@@ -71,10 +71,10 @@ class IncomingForm extends EventEmitter {
   uploadDir: string;
   error: any;
   headers: http.IncomingHttpHeaders | null;
-  type: string | null;
+  type: string | null | undefined;
   bytesExpected: number | null;
   bytesReceived: number | null;
-  _parser: JSONParser | DummyParser | MultipartParser | OctetStreamParser | QueryStringParser;
+  _parser: JSONParser | DummyParser | MultipartParser | OctetStreamParser | QueryStringParser | null;
   req: http.IncomingMessage | null;
   _flushing: number;
   _fieldsSize: number;
@@ -144,8 +144,6 @@ class IncomingForm extends EventEmitter {
         errors.pluginFunction,
       );
     }
-    const a = plugin.bind(this);
-    type b = typeof a;
     this._plugins.push(plugin.bind(this));
     return this;
   }
@@ -179,7 +177,7 @@ class IncomingForm extends EventEmitter {
     return true;
   }
 
-  parse(req: http.IncomingMessage, cb: (err: Error, fields: IFields, files: IFiles) => void) {
+  parse(req: http.IncomingMessage, cb: (err: Error | null, fields: IFields, files: IFiles) => void) {
     this.req = req;
 
     // Setup callback first, so we don't miss anything from data events emitted immediately.
@@ -202,18 +200,6 @@ class IncomingForm extends EventEmitter {
         } else {
           this.fields[name] = value;
         }
-
-        /*
-        if (this.type === 'multipart' || this.type === 'urlencoded') {
-          if (!hasOwnProp(this.fields, name)) {
-            this.fields[name] = [value];
-          } else {
-            this.fields[name].push(value);
-          }
-        } else {
-          this.fields[name] = value;
-        }
-        */
       });
       this.on('file', (name: string, file: IFile) => {
         if (!hasOwnProp(files, name)) {

src/PersistentFile.ts

@@ -18,7 +18,7 @@ class PersistentFile extends EventEmitter implements IFile {
   mimetype: IFile['mimetype'];
   hashAlgorithm: IFile['hashAlgorithm'];
 
-  constructor({ filepath, newFilename, originalFilename, mimetype, hashAlgorithm }: Partial<IFile>) {
+  constructor({ filepath, newFilename, originalFilename, mimetype, hashAlgorithm }: Pick<IFile, "filepath" | "newFilename" | "originalFilename" | "mimetype" | "hashAlgorithm">) {
     super();
 
     this.lastModifiedDate = null;

src/VolatileFile.ts

@@ -18,7 +18,7 @@ class VolatileFile extends EventEmitter implements IFile {
   hashAlgorithm: IFile['hashAlgorithm'];
   createFileWriteStream: IFile['createFileWriteStream'];
 
-  constructor({ filepath, newFilename, originalFilename, mimetype, hashAlgorithm, createFileWriteStream }: Partial<IFile>) {
+  constructor({ filepath, newFilename, originalFilename, mimetype, hashAlgorithm, createFileWriteStream }: Pick<IFile, "filepath" | "newFilename" | "originalFilename" | "mimetype" | "hashAlgorithm" | "createFileWriteStream">) {
     super();
 
     this.lastModifiedDate = null;

src/parsers/Multipart.ts

@@ -42,6 +42,24 @@ function lower(c: any) {
 
 export const STATES = Object.assign({}, STATE);
 
+export type MultipartParserContext = {
+  name: string;
+  buffer?: Buffer;
+  start?: number;
+  end?: number;
+}
+
+interface MultipartParser {
+  push(context: MultipartParserContext, encoding?: BufferEncoding): boolean;
+
+  on(event: 'close', listener: () => void): this;
+  on(event: 'data', listener: (context: {}) => void): this;
+  on(event: 'end', listener: () => void): this;
+  on(event: 'readable', listener: () => void): this;
+  on(event: 'error', listener: (err: Error) => void): this;
+  on(event: string | symbol, listener: (...args: any[]) => void): this;
+}
+
 class MultipartParser extends Transform {
   boundary: Buffer | null;
   boundaryChars: any;

src/plugins/multipart.ts

@@ -2,6 +2,7 @@
 
 import { Stream } from 'node:stream';
 import MultipartParser from '../parsers/Multipart';
+import type { MultipartParserContext } from '../parsers/Multipart';
 import * as errors from '../FormidableError';
 import FormidableError from '../FormidableError';
 import type { Formidable, IFormidableOptions, IPart } from '../types'
@@ -51,7 +52,7 @@ function createInitMultipart(boundary: string) {
     parser.initWithBoundary(boundary);
 
     // eslint-disable-next-line max-statements, consistent-return
-    parser.on('data', ({ name, buffer, start, end }) => {
+    parser.on('data', ({ name, buffer, start, end }: MultipartParserContext) => {
       if (name === 'partBegin') {
         part = new Stream();
         part.readable = true;
@@ -87,25 +88,6 @@ function createInitMultipart(boundary: string) {
         } else if (headerField === 'content-type') {
           part.mimetype = headerValue;
         } else if (headerField === 'content-transfer-encoding') {
-          /*
-          const lowercaseContentTransferEncoding = headerValue.toLowerCase();
-          if (lowercaseContentTransferEncoding === 'binary' ||
-            lowercaseContentTransferEncoding === '7bit' ||
-            lowercaseContentTransferEncoding === '8bit' ||
-            lowercaseContentTransferEncoding === 'utf-8' ||
-            lowercaseContentTransferEncoding === 'base64'
-          ) {
-            part.transferEncoding = lowercaseContentTransferEncoding;
-          } else {
-            return this._error(
-              new FormidableError(
-                'unknown transfer-encoding1',
-                errors.unknownTransferEncoding,
-                501,
-              ),
-            );
-          }
-          */
           part.transferEncoding = headerValue.toLowerCase();
         }
 
@@ -117,24 +99,28 @@ function createInitMultipart(boundary: string) {
           case '7bit':
           case '8bit':
           case 'utf-8': {
-            const dataPropagation = (ctx: any) => {
+            const dataPropagation = (ctx: MultipartParserContext) => {
               if (ctx.name === 'partData') {
                 part.emit('data', ctx.buffer.slice(ctx.start, ctx.end));
               }
             };
-            const dataStopPropagation = (ctx: any) => {
+            const dataStopPropagation = (ctx: MultipartParserContext) => {
               if (ctx.name === 'partEnd') {
                 part.emit('end');
                 parser.off('data', dataPropagation);
                 parser.off('data', dataStopPropagation);
               }
             };
-            parser.on('data', dataPropagation);
+            parser.on('data', (ctx: MultipartParserContext) => {
+              if (ctx.name === 'partData') {
+                part.emit('data', ctx.buffer.slice(ctx.start, ctx.end));
+              }
+            });
             parser.on('data', dataStopPropagation);
             break;
           }
           case 'base64': {
-            const dataPropagation = (ctx: any) => {
+            const dataPropagation = (ctx: MultipartParserContext) => {
               if (ctx.name === 'partData') {
                 part.transferBuffer += ctx.buffer
                   .slice(ctx.start, ctx.end)
@@ -157,7 +143,7 @@ function createInitMultipart(boundary: string) {
                 part.transferBuffer = part.transferBuffer.substring(offset);
               }
             };
-            const dataStopPropagation = (ctx: any) => {
+            const dataStopPropagation = (ctx: MultipartParserContext) => {
               if (ctx.name === 'partEnd') {
                 part.emit('data', Buffer.from(part.transferBuffer, 'base64'));
                 part.emit('end');

src/types.ts

@@ -23,7 +23,7 @@ export interface IFormidableOptions {
   enabledPlugins: FormidablePlugin[];
   fileWriteStreamHandler: (() => Writable) | null;
   defaultInvalidName: string;
-  filter(_part: any): boolean;
+  filter(_part: IPart): boolean;
   filename: ((name: string, ext: string, part: Pick<IPart, 'originalFilename' | 'mimetype'>, form: Formidable) => string) | undefined;
 }
 
@@ -41,7 +41,7 @@ export interface IPart extends Stream {
   name?: string | null;
   originalFilename?: string | null;
   mimetype?: string | null;
-  transferEncoding?: BufferEncoding | '7bit' | '8bit';
+  transferEncoding?: BufferEncoding;
   transferBuffer?: string
 }
 
@@ -55,7 +55,7 @@ export interface IFile {
   /**
    * Unknown
    */
-  length: null;
+  length: number | null;
 
   /**
    * The path this file is being written to. You can modify this in the `'fileBegin'` event in case
@@ -117,8 +117,7 @@ export interface IFile {
   on(event: "end", listener: () => void): this;
 }
 
-interface FileJSON extends Pick<IFile, "size" | "originalFilename" | "mimetype" | "hash">, Partial<Pick<IFile, "filepath">> {
-  length: number;
+interface FileJSON extends Pick<IFile, "size" | "length" | "originalFilename" | "newFilename" | "mimetype" | "hash">, Partial<Pick<IFile, "filepath">> {
   mimetype: string | null;
   mtime?: Date | null;
 }