refactor: replace LoDash isPlainObject, mapValues, and isMap

- `isMap` was added to `util.types` in Node 10.0.
  https://nodejs.org/api/util.html#util_util_types_ismap_value
- `isPlainObject` and `mapValue` both came from LoDash's master branch, which is the pending v5.
- Replace LoDash dependency with `lodash.set` to cover the one use we still have.

Ref: nock#1285

lib/common.js

@@ -1,9 +1,10 @@
 'use strict'
 
-const _ = require('lodash')
 const debug = require('debug')('nock.common')
-const url = require('url')
+const set = require('lodash.set')
 const timers = require('timers')
+const url = require('url')
+const util = require('util')
 
 /**
  * Normalizes the request options so that it always has `host` property.
@@ -194,7 +195,7 @@ function isJSONContent(headers) {
  * Duplicates throw an error.
  */
 function headersFieldNamesToLowerCase(headers) {
-  if (!_.isPlainObject(headers)) {
+  if (!isPlainObject(headers)) {
     throw Error('Headers must be provided as an object')
   }
 
@@ -243,11 +244,11 @@ function headersInputToRawArray(headers) {
   }
 
   // [].concat(...) is used instead of Array.flat until v11 is the minimum Node version
-  if (_.isMap(headers)) {
+  if (util.types.isMap(headers)) {
     return [].concat(...Array.from(headers, ([k, v]) => [k.toString(), v]))
   }
 
-  if (_.isPlainObject(headers)) {
+  if (isPlainObject(headers)) {
     return [].concat(...Object.entries(headers))
   }
 
@@ -359,7 +360,7 @@ function addHeaderLine(headers, name, value) {
  * @fieldName {String} field name - string with the case-insensitive field name
  */
 function deleteHeadersField(headers, fieldNameToDelete) {
-  if (!_.isPlainObject(headers)) {
+  if (!isPlainObject(headers)) {
     throw Error('headers must be an object')
   }
 
@@ -559,7 +560,7 @@ const dataEqual = (expected, actual) =>
  * { 'foo[bar][0]': 'baz' } -> { foo: { bar: [ 'baz' ] } }
  */
 const expand = input =>
-  Object.entries(input).reduce((acc, [k, v]) => _.set(acc, k, v), {})
+  Object.entries(input).reduce((acc, [k, v]) => set(acc, k, v), {})
 
 /**
  * Performs a recursive strict comparison between two values.
@@ -572,7 +573,7 @@ function deepEqual(expected, actual) {
     return expected.test(actual)
   }
 
-  if (Array.isArray(expected) || _.isPlainObject(expected)) {
+  if (Array.isArray(expected) || isPlainObject(expected)) {
     if (actual === undefined) {
       return false
     }
@@ -588,6 +589,51 @@ function deepEqual(expected, actual) {
   return expected === actual
 }
 
+/**
+ * Checks if `value` is a plain object, that is, an object created by the
+ * `Object` constructor or one with a `[[Prototype]]` of `null`.
+ * https://github.com/lodash/lodash/blob/588bf3e20db0ae039a822a14a8fa238c5b298e65/isPlainObject.js
+ *
+ * @param {*} value The value to check.
+ * @return {boolean}
+ */
+function isPlainObject(value) {
+  const isObjectLike = typeof value === 'object' && value !== null
+  const tag = Object.prototype.toString.call(value)
+  if (!isObjectLike || tag !== '[object Object]') {
+    return false
+  }
+  if (Object.getPrototypeOf(value) === null) {
+    return true
+  }
+  let proto = value
+  while (Object.getPrototypeOf(proto) !== null) {
+    proto = Object.getPrototypeOf(proto)
+  }
+  return Object.getPrototypeOf(value) === proto
+}
+
+/**
+ * Creates an object with the same keys as `object` and values generated
+ * by running each own enumerable string keyed property of `object` thru
+ * `iteratee`. (iteration order is not guaranteed)
+ * The iteratee is invoked with three arguments: (value, key, object).
+ * https://github.com/lodash/lodash/blob/588bf3e20db0ae039a822a14a8fa238c5b298e65/mapValue.js
+ *
+ * @param {Object} object The object to iterate over.
+ * @param {Function} iteratee The function invoked per iteration.
+ * @returns {Object} Returns the new mapped object.
+ */
+function mapValue(object, iteratee) {
+  object = Object(object)
+  const result = {}
+
+  Object.keys(object).forEach(key => {
+    result[key] = iteratee(object[key], key, object)
+  })
+  return result
+}
+
 const timeouts = []
 const intervals = []
 const immediates = []
@@ -614,29 +660,33 @@ function removeAllTimers() {
   clearTimer(clearImmediate, immediates)
 }
 
-exports.normalizeClientRequestArgs = normalizeClientRequestArgs
-exports.normalizeRequestOptions = normalizeRequestOptions
-exports.normalizeOrigin = normalizeOrigin
-exports.isUtf8Representable = isUtf8Representable
-exports.overrideRequests = overrideRequests
-exports.restoreOverriddenRequests = restoreOverriddenRequests
-exports.stringifyRequest = stringifyRequest
-exports.isContentEncoded = isContentEncoded
-exports.contentEncoding = contentEncoding
-exports.isJSONContent = isJSONContent
-exports.headersFieldNamesToLowerCase = headersFieldNamesToLowerCase
-exports.headersFieldsArrayToLowerCase = headersFieldsArrayToLowerCase
-exports.headersArrayToObject = headersArrayToObject
-exports.headersInputToRawArray = headersInputToRawArray
-exports.deleteHeadersField = deleteHeadersField
-exports.forEachHeader = forEachHeader
-exports.percentEncode = percentEncode
-exports.percentDecode = percentDecode
-exports.matchStringOrRegexp = matchStringOrRegexp
-exports.formatQueryValue = formatQueryValue
-exports.isStream = isStream
-exports.dataEqual = dataEqual
-exports.setTimeout = setTimeout
-exports.setInterval = setInterval
-exports.setImmediate = setImmediate
-exports.removeAllTimers = removeAllTimers
+module.exports = {
+  contentEncoding,
+  dataEqual,
+  deleteHeadersField,
+  forEachHeader,
+  formatQueryValue,
+  headersArrayToObject,
+  headersFieldNamesToLowerCase,
+  headersFieldsArrayToLowerCase,
+  headersInputToRawArray,
+  isContentEncoded,
+  isJSONContent,
+  isPlainObject,
+  isStream,
+  isUtf8Representable,
+  mapValue,
+  matchStringOrRegexp,
+  normalizeClientRequestArgs,
+  normalizeOrigin,
+  normalizeRequestOptions,
+  overrideRequests,
+  percentDecode,
+  percentEncode,
+  removeAllTimers,
+  restoreOverriddenRequests,
+  setImmediate,
+  setInterval,
+  setTimeout,
+  stringifyRequest,
+}

lib/interceptor.js

@@ -2,7 +2,6 @@
 
 const debug = require('debug')('nock.interceptor')
 const stringify = require('json-stringify-safe')
-const _ = require('lodash')
 const querystring = require('querystring')
 const { URL, URLSearchParams } = require('url')
 
@@ -483,7 +482,7 @@ module.exports = class Interceptor {
       // Normalize the data into the shape that is matched against.
       // Duplicate keys are handled by combining the values into an array.
       queries = querystring.parse(queries.toString())
-    } else if (!_.isPlainObject(queries)) {
+    } else if (!common.isPlainObject(queries)) {
       throw Error(`Argument Error: ${queries}`)
     }
 

lib/match_body.js

@@ -1,6 +1,5 @@
 'use strict'
 
-const _ = require('lodash')
 const querystring = require('querystring')
 
 const common = require('./common')
@@ -70,8 +69,8 @@ function mapValuesDeep(obj, cb) {
   if (Array.isArray(obj)) {
     return obj.map(v => mapValuesDeep(v, cb))
   }
-  if (_.isPlainObject(obj)) {
-    return _.mapValues(obj, v => mapValuesDeep(v, cb))
+  if (common.isPlainObject(obj)) {
+    return common.mapValue(obj, v => mapValuesDeep(v, cb))
   }
   return cb(obj)
 }

package.json

@@ -24,7 +24,7 @@
   "dependencies": {
     "debug": "^4.1.0",
     "json-stringify-safe": "^5.0.1",
-    "lodash": "^4.17.13",
+    "lodash.set": "^4.3.2",
     "propagate": "^2.0.0"
   },
   "devDependencies": {