multer error enhancements

package.json

@@ -5,7 +5,7 @@
   "main": "dist/index.js",
   "scripts": {
     "compile": "rm -rf dist/ && tsc",
-    "test": "mocha -r source-map-support/register -r ts-node/register --recursive test/**/*.spec.ts",
+    "test": "TS_NODE_FILES=true mocha -r source-map-support/register -r ts-node/register  --files --recursive test/**/*.spec.ts",
     "test:coverage": "nyc mocha -r source-map-support/register -r ts-node/register --recursive test/**/*.spec.ts",
     "coveralls": "cat coverage/lcov.info | coveralls -v",
     "codacy": "cat coverage/lcov.info | codacy-coverage"

src/middlewares/openapi.multipart.ts

@@ -8,6 +8,7 @@ import {
   OpenAPIV3,
   ValidationError,
 } from '../framework/types';
+import { MulterError } from 'multer';
 const multer = require('multer');
 
 export function multipart(
@@ -74,14 +75,12 @@ function error(req: OpenApiRequest, err: Error): ValidationError {
     // - 413 ( Request Entity Too Large ) : Too many parts / File too large / Too many files
     // - 400 ( Bad Request ) : Field * too long / Too many fields
     // - 500 ( Internal Server Error ) : Unexpected field
-    const multerError: Express.Multer.MulterError = err;
-    const payload_too_big = /LIMIT_(FILE|PART)_(SIZE|COUNT)/.test(multerError.code);
+    const multerError = <MulterError>err;
+    const payload_too_big = /LIMIT_(FILE|PART)_(SIZE|COUNT)/.test(
+      multerError.code,
+    );
     const unexpected = /LIMIT_UNEXPECTED_FILE/.test(multerError.code);
-    const status = (payload_too_big) 
-          ? 413 
-          : (!unexpected)
-              ? 400
-              : 500;
+    const status = payload_too_big ? 413 : !unexpected ? 400 : 500;
     return validationError(status, req.path, err.message);
   } else {
     // HACK

tsconfig.json

@@ -6,12 +6,12 @@
     "module": "commonjs",
     "outDir": "dist",
     "sourceMap": true,
-    "resolveJsonModule": true
+    "resolveJsonModule": true,
+    "typeRoots": ["./node_modules/@types", "./typings"]
   },
-
   "exclude": ["node_modules"],
   "include": [
-    "typings.d.ts",
+    "typings/**/*.d.ts",
     "src/**/*.ts",
     "src/middlewares/modded.express.mung.ts"
   ]

typings/index.d.ts

@@ -0,0 +1,25 @@
+import * as MulterExt from 'multer';
+
+declare module 'multer' {
+  type ErrorCodes =
+    | 'LIMIT_PART_COUNT'
+    | 'LIMIT_FILE_SIZE'
+    | 'LIMIT_FILE_COUNT'
+    | 'LIMIT_FIELD_KEY'
+    | 'LIMIT_FIELD_VALUE'
+    | 'LIMIT_FIELD_COUNT'
+    | 'LIMIT_UNEXPECTED_FILE';
+
+  interface MulterError extends Error {
+    /* Constructor for MulterError */
+    new (code: ErrorCodes, field?: string);
+    /* Name of the constructor */
+    name: string;
+    /* Error Message */
+    message: string;
+    /* Error code */
+    code: ErrorCodes;
+    /* Field Name */
+    field?: string;
+  }
+}