chore: drop deep-equal devDependency

According to deep-equal's own docs:

> Node's assert.deepEqual() algorithm as a standalone module, that also works in browser environments.

Since the tests are running in Node.js only, we don't need an external dependency.

Author: wojtekmaj

package.json

@@ -30,7 +30,6 @@
     "xtend": "^4.0.2"
   },
   "devDependencies": {
-    "deep-equal": "^2.0.3",
     "express": "^4.21.2",
     "form-data": "^4.0.2",
     "fs-temp": "^1.2.1",

test/disk-storage.js

@@ -1,7 +1,6 @@
 /* eslint-env mocha */
 
 var assert = require('assert')
-var deepEqual = require('deep-equal')
 
 var fs = require('fs')
 var path = require('path')
@@ -71,9 +70,9 @@ describe('Disk Storage', function () {
       assert.strictEqual(req.body.version, '')
       assert.strictEqual(req.body.year, '')
 
-      assert(deepEqual(req.body.checkboxfull, ['cb1', 'cb2']))
-      assert(deepEqual(req.body.checkboxhalfempty, ['cb1', '']))
-      assert(deepEqual(req.body.checkboxempty, ['', '']))
+      assert.deepEqual(req.body.checkboxfull, ['cb1', 'cb2'])
+      assert.deepEqual(req.body.checkboxhalfempty, ['cb1', ''])
+      assert.deepEqual(req.body.checkboxempty, ['', ''])
 
       assert.strictEqual(req.file.fieldname, 'empty')
       assert.strictEqual(req.file.originalname, 'empty.dat')
@@ -107,7 +106,7 @@ describe('Disk Storage', function () {
     util.submitForm(parser, form, function (err, req) {
       assert.ifError(err)
 
-      assert(deepEqual(req.body, {}))
+      assert.deepEqual(req.body, {})
 
       assert.strictEqual(req.files.empty[0].fieldname, 'empty')
       assert.strictEqual(req.files.empty[0].originalname, 'empty.dat')
@@ -158,10 +157,10 @@ describe('Disk Storage', function () {
     util.submitForm(parser, form, function (err, req) {
       assert.strictEqual(err.code, 'LIMIT_UNEXPECTED_FILE')
       assert.strictEqual(err.field, 'small0')
-      assert(deepEqual(err.storageErrors, []))
+      assert.deepEqual(err.storageErrors, [])
 
       var files = fs.readdirSync(uploadDir)
-      assert(deepEqual(files, []))
+      assert.deepEqual(files, [])
 
       done()
     })

test/fields.js

@@ -1,7 +1,6 @@
 /* eslint-env mocha */
 
 var assert = require('assert')
-var deepEqual = require('deep-equal')
 var stream = require('stream')
 
 var util = require('./_util')
@@ -25,11 +24,11 @@ describe('Fields', function () {
 
     util.submitForm(parser, form, function (err, req) {
       assert.ifError(err)
-      assert(deepEqual(req.body, {
+      assert.deepEqual(req.body, {
         name: 'Multer',
         key: 'value',
         abc: 'xyz'
-      }))
+      })
       done()
     })
   })
@@ -49,14 +48,14 @@ describe('Fields', function () {
 
     util.submitForm(parser, form, function (err, req) {
       assert.ifError(err)
-      assert(deepEqual(req.body, {
+      assert.deepEqual(req.body, {
         name: 'Multer',
         key: '',
         abc: '',
         checkboxfull: ['cb1', 'cb2'],
         checkboxhalfempty: ['cb1', ''],
         checkboxempty: ['', '']
-      }))
+      })
       done()
     })
   })
@@ -107,7 +106,7 @@ describe('Fields', function () {
 
       util.submitForm(parser, form, function (err, req) {
         assert.ifError(err)
-        assert(deepEqual(req.body, test.expected))
+        assert.deepEqual(req.body, test.expected)
         done()
       })
     })
@@ -122,13 +121,13 @@ describe('Fields', function () {
 
     util.submitForm(parser, form, function (err, req) {
       assert.ifError(err)
-      assert(deepEqual(req.body, {
+      assert.deepEqual(req.body, {
         obj: {
           0: 'a',
           2: 'c',
           x: 'yz'
         }
-      }))
+      })
       done()
     })
   })

test/memory-storage.js

@@ -1,7 +1,6 @@
 /* eslint-env mocha */
 
 var assert = require('assert')
-var deepEqual = require('deep-equal')
 
 var util = require('./_util')
 var multer = require('../')
@@ -58,9 +57,9 @@ describe('Memory Storage', function () {
       assert.strictEqual(req.body.version, '')
       assert.strictEqual(req.body.year, '')
 
-      assert(deepEqual(req.body.checkboxfull, ['cb1', 'cb2']))
-      assert(deepEqual(req.body.checkboxhalfempty, ['cb1', '']))
-      assert(deepEqual(req.body.checkboxempty, ['', '']))
+      assert.deepEqual(req.body.checkboxfull, ['cb1', 'cb2'])
+      assert.deepEqual(req.body.checkboxhalfempty, ['cb1', ''])
+      assert.deepEqual(req.body.checkboxempty, ['', ''])
 
       assert.strictEqual(req.file.fieldname, 'empty')
       assert.strictEqual(req.file.originalname, 'empty.dat')
@@ -95,7 +94,7 @@ describe('Memory Storage', function () {
     util.submitForm(parser, form, function (err, req) {
       assert.ifError(err)
 
-      assert(deepEqual(req.body, {}))
+      assert.deepEqual(req.body, {})
 
       assert.strictEqual(req.files.empty[0].fieldname, 'empty')
       assert.strictEqual(req.files.empty[0].originalname, 'empty.dat')