fixes(#1283): Add documentation for Multer functions

[arham-sayyed]

PR Title:

docs: Add documentation for Multer functions

fixes: #1283

#1283

Description:

This pull request adds comprehensive documentation for various Multer functions, improving code readability and helping developers understand the purpose and usage of each function. The following functions have been documented:

• allowAll
• Multer.prototype.single
• Multer.prototype.array
• Multer.prototype.fields
• Multer.prototype.none
• Multer.prototype.any
• Multer.prototype._makeMiddleware
• wrappedFileFilter

These additions aim to enhance the clarity of the codebase and provide better insight into the functionality of the Multer library.

Changes:

• Added JSDoc comments for all relevant functions.
• Provided detailed descriptions of each function's behavior and parameters.
• Improved inline documentation to support better developer experience.

Motivation and Context:

Clear documentation helps developers understand how to use the Multer library effectively. This PR aims to improve the usability and maintainability of the code.

Type of Change:

• Documentation update.

How to Test:

No testing required, as this is purely a documentation update. Review the code for clarity and accuracy of the added comments.

[IamLizu]

This adds a lot of changes, in internal methods as well. While the work is appreciated, I suggest changing the PR to DRAFT so that we do not accidentally land it before its ready as there's so much jsDoc to review.

cc: @UlisesGascon

[Copilot]

Pull Request Overview

This PR enhances documentation across Multer by adding detailed JSDoc comments for its storage engines, core middleware, utility classes, and public API methods.

• Added class- and method-level documentation for memory and disk storage engines.
• Documented middleware setup logic, error handling, file appender strategies, and counter utilities.
• Expanded JSDoc on all public Multer APIs (single, array, fields, none, any) with parameter, return, and example annotations.

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
storage/memory.js	Documented MemoryStorage, its _handleFile and _removeFile methods, and the factory export.
storage/disk.js	Documented getFilename, getDestination, DiskStorage class, its _handleFile/_removeFile, and factory.
lib/remove-uploaded-files.js	Documented removeUploadedFiles signature, callback behavior, and recursive removal logic.
lib/multer-error.js	Documented MulterError class, its constructor parameters, and inheritance from Error.
lib/make-middleware.js	Documented drainStream, makeMiddleware, and internal helpers (done, indicateDone, abortWithError, abortWithCode).
lib/file-appender.js	Documented arrayRemove, FileAppender class, and its placeholder/insertion/removal methods.
lib/counter.js	Documented Counter class, its event-driven increment/decrement logic, and onceZero.
index.js	Documented allowAll, Multer constructor, _makeMiddleware, wrappedFileFilter, and public methods (single, array, fields, none, any, multer).

Comments suppressed due to low confidence (5)

storage/memory.js:3

• [nitpick] Consider adding an @constructor or @Class annotation to the JSDoc for MemoryStorage to clearly indicate that it is a constructor function.

function MemoryStorage (opts) {}

storage/disk.js:29

• The os module is referenced here but not imported. Add var os = require('os') at the top of the file to avoid a ReferenceError.

cb(null, os.tmpdir())

lib/remove-uploaded-files.js:13

• This function implements recursive removal of files and aggregates errors; consider adding unit tests for cases with no files, successful removals, and error aggregation.

function removeUploadedFiles (uploadedFiles, remove, cb) {

lib/multer-error.js:20

• [nitpick] Add an @extends Error tag in the JSDoc for MulterError to clearly indicate that it inherits from the native Error class.

function MulterError (code, field) {

lib/counter.js:8

• Counter emits a 'zero' event and manages internal state; consider adding tests to verify event emission when reaching zero and correct increment/decrement behavior.

function Counter () {

[bjohansebas]

Suggested change

	/**
	/**

[bjohansebas]

LGTM, thanks!

[IamLizu]

Looks almost good to me.

[IamLizu]

Since we are doing this, maybe add an explicit @constructor tag?

/**
 * @constructor
 * @param {Object} opts
 * …
 */
function MemoryStorage(opts) { … }

[IamLizu]

maybe add an @extends Error tag so documentation tools know this class inherits from the built-in Error?

/**
 * @extends Error
 * @param {string} code
 * @param {string} field
 */
function MulterError(code, field) { … }