diff --git a/package.json b/package.json
index 7cf0cfcd..73d6213e 100644
--- a/package.json
+++ b/package.json
@@ -5,10 +5,10 @@
   "author": "Jeff Dickey @jdxcode",
   "bugs": "https://github.com/oclif/command/issues",
   "dependencies": {
-    "@oclif/config": "^1",
+    "@oclif/config": "^1.15.1",
     "@oclif/errors": "^1.2.2",
     "@oclif/parser": "^3.8.3",
-    "@oclif/plugin-help": "^2",
+    "@oclif/plugin-help": "^3",
     "debug": "^4.1.1",
     "semver": "^5.6.0"
   },
@@ -27,12 +27,12 @@
     "fancy-test": "^1.4.3",
     "globby": "^9.0.0",
     "mocha": "^6.0.2",
-    "ts-node": "^8.0.3",
-    "typescript": "^3.3.3333"
+    "sinon": "^9.0.1",
+    "ts-node": "^8.8.2",
+    "typescript": "^3.8.3"
   },
   "peerDependencies": {
-    "@oclif/config": "^1",
-    "@oclif/plugin-help": "^2"
+    "@oclif/config": "^1"
   },
   "engines": {
     "node": ">=8.0.0"
diff --git a/src/command.ts b/src/command.ts
index 303ee881..00f9fd3e 100644
--- a/src/command.ts
+++ b/src/command.ts
@@ -2,11 +2,12 @@ const pjson = require('../package.json')
 import * as Config from '@oclif/config'
 import * as Errors from '@oclif/errors'
 import * as Parser from '@oclif/parser'
-import Help from '@oclif/plugin-help'
+import {HelpBase} from '@oclif/plugin-help'
 import {format, inspect} from 'util'
 
 import * as flags from './flags'
 import {sortBy, uniqBy} from './util'
+import {getHelpClass} from '@oclif/plugin-help'
 
 /**
  * swallows stdout epipe errors
@@ -186,8 +187,8 @@ export default abstract class Command {
   }
 
   protected _help() {
-    const HHelp: typeof Help = require('@oclif/plugin-help').default
-    const help = new HHelp(this.config)
+    const HelpClass = getHelpClass(this.config)
+    const help: HelpBase = new HelpClass(this.config)
     const cmd = Config.Command.toCached(this.ctor as any as Config.Command.Class)
     if (!cmd.id) cmd.id = ''
     let topics = this.config.topics
diff --git a/src/main.ts b/src/main.ts
index eaa8a74c..2db52490 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -1,7 +1,8 @@
 import * as Config from '@oclif/config'
-import Help from '@oclif/plugin-help'
+import {HelpBase} from '@oclif/plugin-help'
 
 import {Command} from '.'
+import {getHelpClass} from '@oclif/plugin-help'
 
 export class Main extends Command {
   static run(argv = process.argv.slice(2), options?: Config.LoadOptions) {
@@ -36,8 +37,8 @@ export class Main extends Command {
   }
 
   protected _help() {
-    const HHelp: typeof Help = require('@oclif/plugin-help').default
-    const help = new HHelp(this.config)
+    const HelpClass = getHelpClass(this.config)
+    const help: HelpBase = new HelpClass(this.config)
     help.showHelp(this.argv)
     return this.exit(0)
   }
diff --git a/test/command.test.ts b/test/command.test.ts
index e566249d..40062644 100644
--- a/test/command.test.ts
+++ b/test/command.test.ts
@@ -2,6 +2,10 @@ import * as Config from '@oclif/config'
 import {expect, fancy} from 'fancy-test'
 
 import Base, {flags} from '../src'
+import {TestHelpClassConfig} from './helpers/test-help-in-src/src/test-help-plugin'
+import * as PluginHelp from '@oclif/plugin-help'
+
+const originalgetHelpClass = PluginHelp.getHelpClass
 
 // const pjson = require('../package.json')
 
@@ -267,6 +271,144 @@ USAGE
 
 `)
     })
+
+    fancy
+    .stdout()
+    .add('config', async () => {
+      const config: TestHelpClassConfig = await Config.load()
+      config.pjson.oclif.helpClass = 'help-class-does-not-exist'
+      return config
+    })
+    .do(async ({config}) => {
+      class CMD extends Command {
+        config = config
+      }
+      await CMD.run(['-h'])
+    })
+    .catch((error: Error) => expect(error.message).to.contain('Unable to load configured help class "help-class-does-not-exist", failed with message:\n'))
+    .it('shows useful error message when configured help class cannot be loaded')
+
+    fancy
+    .stdout()
+    .stub(PluginHelp, 'getHelpClass', function (config: any) {
+      return originalgetHelpClass(config, '')
+    })
+    .add('config', async () => {
+      const config: TestHelpClassConfig = await Config.load()
+      config.pjson.oclif.helpClass = undefined
+      return config
+    })
+    .do(async ({config}) => {
+      class CMD extends Command {
+        config = config
+      }
+      await CMD.run(['-h'])
+    })
+    .catch((error: Error) => expect(error.message).to.contain('Could not load a help class, consider installing the @oclif/plugin-help package, failed with message:\n'))
+    .it('shows useful error message when no help class has been configured and the default cannot be loaded')
+
+    describe('from a help class', () => {
+      fancy
+      .stdout()
+      .stub(PluginHelp, 'getHelpClass', function (config: Config.IConfig) {
+        const patchedConfig = {
+          ...config,
+          root: `${__dirname}/helpers/test-help-in-lib/`,
+        }
+
+        return originalgetHelpClass(patchedConfig)
+      })
+      .add('config', async () => {
+        const config: TestHelpClassConfig = await Config.load()
+        config.pjson.oclif.helpClass = './lib/test-help-plugin'
+        return config
+      })
+      .do(async ({config}) => {
+        class CMD extends Command {
+          static id = 'test-command-for-help-plugin'
+
+          config = config
+        }
+        await CMD.run(['-h'])
+      })
+      .catch(/EEXIT: 0/)
+      .it('-h via a plugin in lib dir (compiled to js)', ctx => {
+        expect(ctx.stdout).to.equal('hello from test-help-plugin #showCommandHelp in the lib folder and in compiled javascript\n')
+        expect(ctx.config.showCommandHelpSpy!.getCalls().length).to.equal(1)
+        expect(ctx.config.showHelpSpy!.getCalls().length).to.equal(0)
+        const [Command, Topics] = ctx.config.showCommandHelpSpy!.firstCall.args
+        expect(Command.id).to.deep.equal('test-command-for-help-plugin')
+        expect(Topics).to.be.an('array')
+      })
+
+      fancy
+      .stdout()
+      .stub(PluginHelp, 'getHelpClass', function (config: Config.IConfig) {
+        const patchedConfig = {
+          ...config,
+          root: `${__dirname}/helpers/test-help-in-src/`,
+        }
+
+        return originalgetHelpClass(patchedConfig)
+      })
+      .add('config', async () => {
+        const config: TestHelpClassConfig = await Config.load()
+        config.pjson.oclif.helpClass = './lib/test-help-plugin'
+        return config
+      })
+      .do(async ({config}) => {
+        class CMD extends Command {
+          static id = 'test-command-for-help-plugin'
+
+          config = config
+        }
+        await CMD.run(['-h'])
+      })
+      .catch(/EEXIT: 0/)
+      .it('-h via a plugin in src dir (source in ts)', ctx => {
+        expect(ctx.stdout).to.equal('hello from test-help-plugin #showCommandHelp\n')
+        expect(ctx.config.showCommandHelpSpy!.getCalls().length).to.equal(1)
+        expect(ctx.config.showHelpSpy!.getCalls().length).to.equal(0)
+        const [Command, Topics] = ctx.config.showCommandHelpSpy!.firstCall.args
+        expect(Command.id).to.deep.equal('test-command-for-help-plugin')
+        expect(Topics).to.be.an('array')
+      })
+
+      fancy
+      .stdout()
+      .stub(PluginHelp, 'getHelpClass', function (config: Config.IConfig) {
+        const patchedConfig = {
+          ...config,
+          root: `${__dirname}/helpers/test-help-in-src/`,
+        }
+
+        return originalgetHelpClass(patchedConfig)
+      })
+      .add('config', async () => {
+        const config: TestHelpClassConfig = await Config.load()
+        config.pjson.oclif.helpClass = './lib/test-help-plugin'
+        return config
+      })
+      .do(async ({config}) => {
+        class CMD extends Command {
+          static id = 'test-command-for-help-plugin'
+
+          config = config
+
+          static flags = {help: flags.help()}
+        }
+        return CMD.run(['--help'])
+      })
+      .catch(/EEXIT: 0/)
+      .it('--help via a plugin in src dir (source in ts)', ctx => {
+        expect(ctx.stdout).to.equal('hello from test-help-plugin #showCommandHelp\n')
+        expect(ctx.config.showCommandHelpSpy!.getCalls().length).to.equal(1)
+        expect(ctx.config.showHelpSpy!.getCalls().length).to.equal(0)
+        const [Command, Topics] = ctx.config.showCommandHelpSpy!.firstCall.args
+        expect(Command.id).to.deep.equal('test-command-for-help-plugin')
+        expect(Topics).to.be.an('array')
+      })
+    })
   })
 
   describe('.log()', () => {
diff --git a/test/helpers/test-help-in-lib/lib/test-help-plugin.js b/test/helpers/test-help-in-lib/lib/test-help-plugin.js
new file mode 100644
index 00000000..77e76fd8
--- /dev/null
+++ b/test/helpers/test-help-in-lib/lib/test-help-plugin.js
@@ -0,0 +1,20 @@
+/* eslint-disable */
+'use strict';
+Object.defineProperty (exports, '__esModule', {value: true});
+const sinon_1 = require ('sinon');
+class default_1 {
+  constructor (config, opts) {
+    this.showCommandHelp = sinon_1.spy (() => {
+      console.log ('hello from test-help-plugin #showCommandHelp in the lib folder and in compiled javascript');
+    });
+    this.showHelp = sinon_1.spy (() => {
+      console.log ('hello showHelp');
+    });
+    config.showCommandHelpSpy = this.showCommandHelp;
+    config.showHelpSpy = this.showHelp;
+  }
+  command () {
+    throw new Error ('not needed for testing @oclif/command');
+  }
+}
+exports.default = default_1;
diff --git a/test/helpers/test-help-in-src/src/test-help-plugin.ts b/test/helpers/test-help-in-src/src/test-help-plugin.ts
new file mode 100644
index 00000000..4456deeb
--- /dev/null
+++ b/test/helpers/test-help-in-src/src/test-help-plugin.ts
@@ -0,0 +1,25 @@
+import {HelpBase} from '@oclif/plugin-help'
+import {spy, SinonSpy} from 'sinon'
+import {IConfig} from '@oclif/config'
+
+export type TestHelpClassConfig = IConfig & { showCommandHelpSpy?: SinonSpy; showHelpSpy?: SinonSpy }
+
+export default class extends HelpBase {
+  constructor(config: any, opts: any) {
+    super(config, opts)
+    config.showCommandHelpSpy = this.showCommandHelp
+    config.showHelpSpy = this.showHelp
+  }
+
+  showCommandHelp = spy(() => {
+    console.log('hello from test-help-plugin #showCommandHelp')
+  })
+
+  showHelp = spy(() => {
+    console.log('hello showHelp')
+  })
+
+  getCommandHelpForReadme(): string {
+    throw new Error('not needed for testing @oclif/command')
+  }
+}
diff --git a/test/helpers/test-help-in-src/tsconfig.json b/test/helpers/test-help-in-src/tsconfig.json
new file mode 100644
index 00000000..79c7711d
--- /dev/null
+++ b/test/helpers/test-help-in-src/tsconfig.json
@@ -0,0 +1,6 @@
+{
+    "compilerOptions": {
+        "rootDir": "./src",
+        "outDir": "./lib"
+    }
+}
diff --git a/test/main.test.ts b/test/main.test.ts
index 0f2dafe0..3402b671 100644
--- a/test/main.test.ts
+++ b/test/main.test.ts
@@ -1,9 +1,13 @@
 import {expect, fancy} from 'fancy-test'
 
 import {Main} from '../src/main'
+import * as PluginHelp from '@oclif/plugin-help'
+import * as Config from '@oclif/config'
+import {TestHelpClassConfig} from './helpers/test-help-in-src/src/test-help-plugin'
 
 const pjson = require('../package.json')
 const version = `@oclif/command/${pjson.version} ${process.platform}-${process.arch} node-${process.version}`
+const originalgetHelpClass = PluginHelp.getHelpClass
 
 describe('main', () => {
   fancy
@@ -31,10 +35,71 @@ VERSION
 USAGE
   $ @oclif/command [COMMAND]
 
+TOPICS
+  plugins  list installed plugins
+
 COMMANDS
   help     display help for @oclif/command
   plugins  list installed plugins
 
 `))
   .it('runs -h')
+
+  describe('with an alternative help class', async () => {
+    const getMainWithHelpClass = async () => {
+      const config: TestHelpClassConfig = await Config.load()
+      config.pjson.oclif.helpClass = './lib/test-help-plugin'
+
+      class MainWithHelpClass extends Main {
+        config = config
+      }
+
+      return MainWithHelpClass
+    }
+
+    fancy
+    .stdout()
+    .stub(PluginHelp, 'getHelpClass', function (config: Config.IConfig) {
+      const patchedConfig = {
+        ...config,
+        root: `${__dirname}/helpers/test-help-in-src/`,
+      }
+
+      return originalgetHelpClass(patchedConfig)
+    })
+    .do(async () => (await getMainWithHelpClass()).run(['-h']))
+    .catch('EEXIT: 0')
+    .do(output => expect(output.stdout).to.equal('hello showHelp\n'))
+    .it('works with -h')
+
+    fancy
+    .stdout()
+    .stub(PluginHelp, 'getHelpClass', function (config: Config.IConfig) {
+      const patchedConfig = {
+        ...config,
+        root: `${__dirname}/helpers/test-help-in-src/`,
+      }
+
+      return originalgetHelpClass(patchedConfig)
+    })
+    .do(async () => (await getMainWithHelpClass()).run(['--help']))
+    .catch('EEXIT: 0')
+    .do(output => expect(output.stdout).to.equal('hello showHelp\n'))
+    .it('works with --help')
+
+    fancy
+    .stdout()
+    .stub(PluginHelp, 'getHelpClass', function (config: Config.IConfig) {
+      const patchedConfig = {
+        ...config,
+        root: `${__dirname}/helpers/test-help-in-src/`,
+      }
+
+      return originalgetHelpClass(patchedConfig)
+    })
+    .do(async () => (await getMainWithHelpClass()).run(['help']))
+    .catch('EEXIT: 0')
+    .do(output => expect(output.stdout).to.equal('hello showHelp\n'))
+    .it('works with help')
+  })
 })
diff --git a/yarn.lock b/yarn.lock
index bada72d9..9d7392ad 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -62,7 +62,19 @@
     debug "^4.1.1"
     semver "^5.6.0"
 
-"@oclif/config@^1":
+"@oclif/command@^1.5.20":
+  version "1.5.20"
+  resolved "https://registry.yarnpkg.com/@oclif/command/-/command-1.5.20.tgz#bb0693586d7d66a457c49b719e394c02ff0169a7"
+  integrity sha512-lzst5RU/STfoutJJv4TLE/cm1WtW3xy6Aqvqy3r1lPsGdNifgbEq4dCOYyc/ZEuhV/IStQLDFTnAlqTdolkz1Q==
+  dependencies:
+    "@oclif/config" "^1"
+    "@oclif/errors" "^1.2.2"
+    "@oclif/parser" "^3.8.3"
+    "@oclif/plugin-help" "^2"
+    debug "^4.1.1"
+    semver "^5.6.0"
+
+"@oclif/config@^1", "@oclif/config@^1.15.1":
   version "1.15.1"
   resolved "https://registry.yarnpkg.com/@oclif/config/-/config-1.15.1.tgz#39950c70811ab82d75bb3cdb33679ed0a4c21c57"
   integrity sha512-GdyHpEZuWlfU8GSaZoiywtfVBsPcfYn1KuSLT1JTfvZGpPG6vShcGr24YZ3HG2jXUFlIuAqDcYlTzOrqOdTPNQ==
@@ -107,12 +119,27 @@
     tslib "^1.9.3"
 
 "@oclif/plugin-help@^2":
-  version "2.2.3"
-  resolved "https://registry.yarnpkg.com/@oclif/plugin-help/-/plugin-help-2.2.3.tgz#b993041e92047f0e1762668aab04d6738ac06767"
-  integrity sha512-bGHUdo5e7DjPJ0vTeRBMIrfqTRDBfyR5w0MP41u0n3r7YG5p14lvMmiCXxi6WDaP2Hw5nqx3PnkAIntCKZZN7g==
+  version "2.2.1"
+  resolved "https://registry.yarnpkg.com/@oclif/plugin-help/-/plugin-help-2.2.1.tgz#cb4d23e453b19340b07c48fb299948b7c74366d3"
+  integrity sha512-psEA3t41MSGBErLk6xCaAq2jKrRtx3Br+kHpd43vZeGEeZ7Gos4wgK0JAaHBbvhvUQskCHg8dzoqv4XEeTWeVQ==
   dependencies:
     "@oclif/command" "^1.5.13"
     chalk "^2.4.1"
+    indent-string "^3.2.0"
+    lodash.template "^4.4.0"
+    string-width "^3.0.0"
+    strip-ansi "^5.0.0"
+    widest-line "^2.0.1"
+    wrap-ansi "^4.0.0"
+
+"@oclif/plugin-help@^3":
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/@oclif/plugin-help/-/plugin-help-3.0.0.tgz#7d6433d74b0473a43797c6e0468b503470f23b50"
+  integrity sha512-mrV1O1VXy+ssW0kmIvFYkuEEPYZWKpyqydyHbKa316esAHatsZlrw6cRItf3TuKHTAqeGuXPctPV4mO2e21F9w==
+  dependencies:
+    "@oclif/command" "^1.5.20"
+    "@oclif/config" "^1.15.1"
+    chalk "^2.4.1"
     indent-string "^4.0.0"
     lodash.template "^4.4.0"
     string-width "^3.0.0"
@@ -143,6 +170,42 @@
   resolved "https://registry.yarnpkg.com/@oclif/screen/-/screen-1.0.4.tgz#b740f68609dfae8aa71c3a6cab15d816407ba493"
   integrity sha512-60CHpq+eqnTxLZQ4PGHYNwUX572hgpMHGPtTWMjdTMsAvlm69lZV/4ly6O3sAYkomo4NggGcomrDpBe34rxUqw==
 
+"@sinonjs/commons@^1", "@sinonjs/commons@^1.6.0", "@sinonjs/commons@^1.7.0":
+  version "1.7.1"
+  resolved "https://registry.yarnpkg.com/@sinonjs/commons/-/commons-1.7.1.tgz#da5fd19a5f71177a53778073978873964f49acf1"
+  integrity sha512-Debi3Baff1Qu1Unc3mjJ96MgpbwTn43S1+9yJ0llWygPwDNu2aaWBD6yc9y/Z8XDRNhx7U+u2UDg2OGQXkclUQ==
+  dependencies:
+    type-detect "4.0.8"
+
+"@sinonjs/fake-timers@^6.0.0":
+  version "6.0.1"
+  resolved "https://registry.yarnpkg.com/@sinonjs/fake-timers/-/fake-timers-6.0.1.tgz#293674fccb3262ac782c7aadfdeca86b10c75c40"
+  integrity sha512-MZPUxrmFubI36XS1DI3qmI0YdN1gks62JtFZvxR67ljjSNCeK6U08Zx4msEWOXuofgqUt6zPHSi1H9fbjR/NRA==
+  dependencies:
+    "@sinonjs/commons" "^1.7.0"
+
+"@sinonjs/formatio@^5.0.1":
+  version "5.0.1"
+  resolved "https://registry.yarnpkg.com/@sinonjs/formatio/-/formatio-5.0.1.tgz#f13e713cb3313b1ab965901b01b0828ea6b77089"
+  integrity sha512-KaiQ5pBf1MpS09MuA0kp6KBQt2JUOQycqVG1NZXvzeaXe5LGFqAKueIS0bw4w0P9r7KuBSVdUk5QjXsUdu2CxQ==
+  dependencies:
+    "@sinonjs/commons" "^1"
+    "@sinonjs/samsam" "^5.0.2"
+
+"@sinonjs/samsam@^5.0.2", "@sinonjs/samsam@^5.0.3":
+  version "5.0.3"
+  resolved "https://registry.yarnpkg.com/@sinonjs/samsam/-/samsam-5.0.3.tgz#86f21bdb3d52480faf0892a480c9906aa5a52938"
+  integrity sha512-QucHkc2uMJ0pFGjJUDP3F9dq5dx8QIaqISl9QgwLOh6P9yv877uONPGXh/OH/0zmM3tW1JjuJltAZV2l7zU+uQ==
+  dependencies:
+    "@sinonjs/commons" "^1.6.0"
+    lodash.get "^4.4.2"
+    type-detect "^4.0.8"
+
+"@sinonjs/text-encoding@^0.7.1":
+  version "0.7.1"
+  resolved "https://registry.yarnpkg.com/@sinonjs/text-encoding/-/text-encoding-0.7.1.tgz#8da5c6530915653f3a1f38fd5f101d8c3f8079c5"
+  integrity sha512-+iTbntw2IZPb/anVDbypzfQa+ay64MW0Zo8aJ8gZPWMMK6/OubMVb6lUPMagqjOPnmtauXnFCACVl3O7ogjeqQ==
+
 "@types/chai@*", "@types/chai@^4.1.7":
   version "4.1.7"
   resolved "https://registry.yarnpkg.com/@types/chai/-/chai-4.1.7.tgz#1b8e33b61a8c09cbe1f85133071baa0dbf9fa71a"
@@ -948,11 +1011,16 @@ detect-file@^1.0.0:
   resolved "https://registry.yarnpkg.com/detect-file/-/detect-file-1.0.0.tgz#f0d66d03672a825cb1b73bdb3fe62310c8e552b7"
   integrity sha1-8NZtA2cqglyxtzvbP+YjEMjlUrc=
 
-diff@3.5.0, diff@^3.1.0:
+diff@3.5.0:
   version "3.5.0"
   resolved "https://registry.yarnpkg.com/diff/-/diff-3.5.0.tgz#800c0dd1e0a8bfbc95835c202ad220fe317e5a12"
   integrity sha512-A46qtFgd+g7pDZinpnwiRJtxbC1hpgf0uzP3iG89scHk0AUC7A1TGxf5OiiOUv/JMZR8GOt8hL900hV0bOy5xA==
 
+diff@^4.0.1, diff@^4.0.2:
+  version "4.0.2"
+  resolved "https://registry.yarnpkg.com/diff/-/diff-4.0.2.tgz#60f3aecb89d5fae520c11aa19efc2bb982aade7d"
+  integrity sha512-58lmxKSA4BNyLz+HHMUzlOEpg09FV+ev6ZMe3vJihgdxzgcwZ8VoEEPmALCZG9LmqfVoNMMKpttIYTVG6uDY7A==
+
 dir-glob@^2.2.1:
   version "2.2.2"
   resolved "https://registry.yarnpkg.com/dir-glob/-/dir-glob-2.2.2.tgz#fa09f0694153c8918b18ba0deafae94769fc50c4"
@@ -1625,6 +1693,11 @@ has-flag@^3.0.0:
   resolved "https://registry.yarnpkg.com/has-flag/-/has-flag-3.0.0.tgz#b5d454dc2199ae225699f3467e5a07f3b955bafd"
   integrity sha1-tdRU3CGZriJWmfNGfloH87lVuv0=
 
+has-flag@^4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/has-flag/-/has-flag-4.0.0.tgz#944771fd9c81c81265c4d6941860da06bb59479b"
+  integrity sha512-EykJT/Q1KjTWctppgIAgfSO0tKVuZUjhgMr17kqTumMl6Afv3EISleU7qZUzoXDFTAHTDC4NOoG/ZxU3EvlMPQ==
+
 has-symbols@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/has-symbols/-/has-symbols-1.0.0.tgz#ba1a8f1af2a0fc39650f5c850367704122063b44"
@@ -2003,6 +2076,11 @@ is-wsl@^1.1.0:
   resolved "https://registry.yarnpkg.com/is-wsl/-/is-wsl-1.1.0.tgz#1f16e4aa22b04d1336b66188a66af3c600c3a66d"
   integrity sha1-HxbkqiKwTRM2tmGIpmrzxgDDpm0=
 
+isarray@0.0.1:
+  version "0.0.1"
+  resolved "https://registry.yarnpkg.com/isarray/-/isarray-0.0.1.tgz#8a18acfca9a8f4177e09abfc6038939b05d1eedf"
+  integrity sha1-ihis/Kmo9Bd+Cav8YDiTmwXR7t8=
+
 isarray@1.0.0, isarray@~1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/isarray/-/isarray-1.0.0.tgz#bb935d48582cba168c06834957a54a3e07124f11"
@@ -2078,6 +2156,11 @@ jsonparse@^1.2.0:
   resolved "https://registry.yarnpkg.com/jsonparse/-/jsonparse-1.3.1.tgz#3f4dae4a91fac315f71062f8521cc239f1366280"
   integrity sha1-P02uSpH6wxX3EGL4UhzCOfE2YoA=
 
+just-extend@^4.0.2:
+  version "4.1.0"
+  resolved "https://registry.yarnpkg.com/just-extend/-/just-extend-4.1.0.tgz#7278a4027d889601640ee0ce0e5a00b992467da4"
+  integrity sha512-ApcjaOdVTJ7y4r08xI5wIqpvwS48Q0PBG4DJROcEkH1f8MdAiNFyFxz3xoL0LWAVwjrwPYZdVHHxhRHcx/uGLA==
+
 kind-of@^3.0.2, kind-of@^3.0.3, kind-of@^3.2.0:
   version "3.2.2"
   resolved "https://registry.yarnpkg.com/kind-of/-/kind-of-3.2.2.tgz#31ea21a734bab9bbb0f32466d893aea51e4a3c64"
@@ -2496,6 +2579,17 @@ nice-try@^1.0.4:
   resolved "https://registry.yarnpkg.com/nice-try/-/nice-try-1.0.5.tgz#a3378a7696ce7d223e88fc9b764bd7ef1089e366"
   integrity sha512-1nh45deeb5olNY7eX82BkPO7SSxR5SSYJiPTrTdFUVYwAl8CKMA5N9PjTYkHiRjisVcxcQ1HXdLhx2qxxJzLNQ==
 
+nise@^4.0.1:
+  version "4.0.3"
+  resolved "https://registry.yarnpkg.com/nise/-/nise-4.0.3.tgz#9f79ff02fa002ed5ffbc538ad58518fa011dc913"
+  integrity sha512-EGlhjm7/4KvmmE6B/UFsKh7eHykRl9VH+au8dduHLCyWUO/hr7+N+WtTvDUwc9zHuM1IaIJs/0lQ6Ag1jDkQSg==
+  dependencies:
+    "@sinonjs/commons" "^1.7.0"
+    "@sinonjs/fake-timers" "^6.0.0"
+    "@sinonjs/text-encoding" "^0.7.1"
+    just-extend "^4.0.2"
+    path-to-regexp "^1.7.0"
+
 node-environment-flags@1.0.4:
   version "1.0.4"
   resolved "https://registry.yarnpkg.com/node-environment-flags/-/node-environment-flags-1.0.4.tgz#0b784a6551426bfc16d3b2208424dcbc2b2ff038"
@@ -2754,6 +2848,13 @@ path-parse@^1.0.6:
   resolved "https://registry.yarnpkg.com/path-parse/-/path-parse-1.0.6.tgz#d62dbb5679405d72c4737ec58600e9ddcf06d24c"
   integrity sha512-GSmOT2EbHrINBf9SR7CDELwlJ8AENk3Qn7OikK4nFYAu3Ote2+JYNVvkpAEQm3/TLNEJFD/xZJjzyxg3KBWOzw==
 
+path-to-regexp@^1.7.0:
+  version "1.8.0"
+  resolved "https://registry.yarnpkg.com/path-to-regexp/-/path-to-regexp-1.8.0.tgz#887b3ba9d84393e87a0a0b9f4cb756198b53548a"
+  integrity sha512-n43JRhlUKUAlibEJhPeir1ncUID16QnEjNpwzNdO3Lm4ywrBpBZ5oLD0I6br9evr1Y9JTqwRtAh7JLoOzAQdVA==
+  dependencies:
+    isarray "0.0.1"
+
 path-type@^1.0.0:
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/path-type/-/path-type-1.1.0.tgz#59c44f7ee491da704da415da5a4070ba4f8fe441"
@@ -3095,6 +3196,19 @@ signal-exit@^3.0.0, signal-exit@^3.0.2:
   resolved "https://registry.yarnpkg.com/signal-exit/-/signal-exit-3.0.2.tgz#b5fdc08f1287ea1178628e415e25132b73646c6d"
   integrity sha1-tf3AjxKH6hF4Yo5BXiUTK3NkbG0=
 
+sinon@^9.0.1:
+  version "9.0.1"
+  resolved "https://registry.yarnpkg.com/sinon/-/sinon-9.0.1.tgz#dbb18f7d8f5835bcf91578089c0a97b2fffdd73b"
+  integrity sha512-iTTyiQo5T94jrOx7X7QLBZyucUJ2WvL9J13+96HMfm2CGoJYbIPqRfl6wgNcqmzk0DI28jeGx5bUTXizkrqBmg==
+  dependencies:
+    "@sinonjs/commons" "^1.7.0"
+    "@sinonjs/fake-timers" "^6.0.0"
+    "@sinonjs/formatio" "^5.0.1"
+    "@sinonjs/samsam" "^5.0.3"
+    diff "^4.0.2"
+    nise "^4.0.1"
+    supports-color "^7.1.0"
+
 slash@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/slash/-/slash-2.0.0.tgz#de552851a1759df3a8f206535442f5ec4ddeab44"
@@ -3364,6 +3478,13 @@ supports-color@^5.0.0, supports-color@^5.3.0, supports-color@^5.4.0, supports-co
   dependencies:
     has-flag "^3.0.0"
 
+supports-color@^7.1.0:
+  version "7.1.0"
+  resolved "https://registry.yarnpkg.com/supports-color/-/supports-color-7.1.0.tgz#68e32591df73e25ad1c4b49108a2ec507962bfd1"
+  integrity sha512-oRSIpR8pxT1Wr2FquTNnGet79b3BWljqOuoW/h4oBhxJ/HUbX5nX6JSruTkvXDCFMwDPvsaTTbvMLKZWSy0R5g==
+  dependencies:
+    has-flag "^4.0.0"
+
 supports-hyperlinks@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/supports-hyperlinks/-/supports-hyperlinks-1.0.1.tgz#71daedf36cc1060ac5100c351bb3da48c29c0ef7"
@@ -3465,16 +3586,16 @@ trim-off-newlines@^1.0.0:
   resolved "https://registry.yarnpkg.com/trim-off-newlines/-/trim-off-newlines-1.0.1.tgz#9f9ba9d9efa8764c387698bcbfeb2c848f11adb3"
   integrity sha1-n5up2e+odkw4dpi8v+sshI8RrbM=
 
-ts-node@^8.0.3:
-  version "8.0.3"
-  resolved "https://registry.yarnpkg.com/ts-node/-/ts-node-8.0.3.tgz#aa60b836a24dafd8bf21b54766841a232fdbc641"
-  integrity sha512-2qayBA4vdtVRuDo11DEFSsD/SFsBXQBRZZhbRGSIkmYmVkWjULn/GGMdG10KVqkaGndljfaTD8dKjWgcejO8YA==
+ts-node@^8.8.2:
+  version "8.8.2"
+  resolved "https://registry.yarnpkg.com/ts-node/-/ts-node-8.8.2.tgz#0b39e690bee39ea5111513a9d2bcdc0bc121755f"
+  integrity sha512-duVj6BpSpUpD/oM4MfhO98ozgkp3Gt9qIp3jGxwU2DFvl/3IRaEAvbLa8G60uS7C77457e/m5TMowjedeRxI1Q==
   dependencies:
     arg "^4.1.0"
-    diff "^3.1.0"
+    diff "^4.0.1"
     make-error "^1.1.1"
     source-map-support "^0.5.6"
-    yn "^3.0.0"
+    yn "3.1.1"
 
 tslib@^1, tslib@^1.8.1:
   version "1.9.3"
@@ -3512,7 +3633,7 @@ type-check@~0.3.2:
   dependencies:
     prelude-ls "~1.1.2"
 
-type-detect@^4.0.0, type-detect@^4.0.5:
+type-detect@4.0.8, type-detect@^4.0.0, type-detect@^4.0.5, type-detect@^4.0.8:
   version "4.0.8"
   resolved "https://registry.yarnpkg.com/type-detect/-/type-detect-4.0.8.tgz#7646fb5f18871cfbb7749e69bd39a6388eb7450c"
   integrity sha512-0fr/mIH1dlO+x7TlcMy+bIDqKPsw/70tVyeHW787goQjhmqaZe10uwLujubK9q9Lg6Fiho1KUKDYz0Z7k7g5/g==
@@ -3522,10 +3643,10 @@ type-fest@^0.5.2:
   resolved "https://registry.yarnpkg.com/type-fest/-/type-fest-0.5.2.tgz#d6ef42a0356c6cd45f49485c3b6281fc148e48a2"
   integrity sha512-DWkS49EQKVX//Tbupb9TFa19c7+MK1XmzkrZUR8TAktmE/DizXoaoJV6TZ/tSIPXipqNiRI6CyAe7x69Jb6RSw==
 
-typescript@^3.3.3333:
-  version "3.3.3333"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.3.3333.tgz#171b2c5af66c59e9431199117a3bcadc66fdcfd6"
-  integrity sha512-JjSKsAfuHBE/fB2oZ8NxtRTk5iGcg6hkYXMnZ3Wc+b2RSqejEqTaem11mHASMnFilHrax3sLK0GDzcJrekZYLw==
+typescript@^3.8.3:
+  version "3.8.3"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.8.3.tgz#409eb8544ea0335711205869ec458ab109ee1061"
+  integrity sha512-MYlEfn5VrLNsgudQTVJeNaQFUAI7DkhnOjdpAp4T+ku1TfQClewlbSuTVHiA+8skNBgaf02TL/kLOvig4y3G8w==
 
 uglify-js@^3.1.4:
   version "3.7.3"
@@ -3713,7 +3834,7 @@ yarn@^1.13.0:
   resolved "https://registry.yarnpkg.com/yarn/-/yarn-1.22.4.tgz#01c1197ca5b27f21edc8bc472cd4c8ce0e5a470e"
   integrity sha512-oYM7hi/lIWm9bCoDMEWgffW8aiNZXCWeZ1/tGy0DWrN6vmzjCXIKu2Y21o8DYVBUtiktwKcNoxyGl/2iKLUNGA==
 
-yn@^3.0.0:
-  version "3.0.0"
-  resolved "https://registry.yarnpkg.com/yn/-/yn-3.0.0.tgz#0073c6b56e92aed652fbdfd62431f2d6b9a7a091"
-  integrity sha512-+Wo/p5VRfxUgBUGy2j/6KX2mj9AYJWOHuhMjMcbBFc3y54o9/4buK1ksBvuiK01C3kby8DH9lSmJdSxw+4G/2Q==
+yn@3.1.1:
+  version "3.1.1"
+  resolved "https://registry.yarnpkg.com/yn/-/yn-3.1.1.tgz#1e87401a09d767c1d5eab26a6e4c185182d2eb50"
+  integrity sha512-Ux4ygGWsu2c7isFWe8Yu1YluJmqVhxqK2cLXNQA5AcC3QfbGNpM7fu0Y8b/z16pXLnFxZYvWhd3fhBY9DLmC6Q==