perf: lazy-load deps

package.json

@@ -9,7 +9,7 @@
     "chalk": "^2.3.2"
   },
   "devDependencies": {
-    "@oclif/errors": "^1.0.3",
+    "@oclif/errors": "^1.0.4",
     "@oclif/tslint": "^1.1.0",
     "@types/chai": "^4.1.2",
     "@types/mocha": "^5.0.0",

src/deps.ts

@@ -0,0 +1,12 @@
+export default () => {
+  const cache: {[k: string]: any} = {}
+  return {
+    add<T, K extends string, U>(this: T, name: K, fn: () => U): T & {[P in K]: U} {
+      Object.defineProperty(this, name, {
+        enumerable: true,
+        get: () => cache[name] || (cache[name] = fn()),
+      })
+      return this as any
+    },
+  }
+}

src/errors.ts

@@ -1,11 +1,18 @@
 import {CLIError} from '@oclif/errors'
 
 import {Arg} from './args'
+import Deps from './deps'
 import * as flags from './flags'
-import {flagUsages} from './help'
-import {renderList} from './list'
+import * as Help from './help'
+import * as List from './list'
 import {ParserInput, ParserOutput} from './parse'
 
+export {CLIError} from '@oclif/errors'
+
+const m = Deps()
+.add('help', () => require('./help') as typeof Help)
+.add('list', () => require('./list') as typeof List)
+
 export interface ICLIParseErrorOptions {
   parse: {
     input?: ParserInput
@@ -30,7 +37,7 @@ export class RequiredArgsError extends CLIParseError {
     let message = `Missing ${args.length} required arg${args.length === 1 ? '' : 's'}`
     const namedArgs = args.filter(a => a.name)
     if (namedArgs.length) {
-      const list = renderList(namedArgs.map(a => [a.name, a.description] as [string, string]))
+      const list = m.list.renderList(namedArgs.map(a => [a.name, a.description] as [string, string]))
       message += `:\n${list}`
     }
     super({parse, message})
@@ -42,7 +49,7 @@ export class RequiredFlagError extends CLIParseError {
   public flags: flags.IFlag<any>[]
 
   constructor({flags, parse}: ICLIParseErrorOptions & { flags: flags.IFlag<any>[] }) {
-    const usage = renderList(flagUsages(flags, {displayRequired: false}))
+    const usage = m.list.renderList(m.help.flagUsages(flags, {displayRequired: false}))
     const message = `Missing required flag${flags.length === 1 ? '' : 's'}:\n${usage}`
     super({parse, message})
     this.flags = flags

src/help.ts

@@ -1,12 +1,12 @@
-import chalk from 'chalk'
+import Chalk from 'chalk'
 
+import Deps from './deps'
 import {IFlag} from './flags'
-import {sortBy} from './util'
+import * as Util from './util'
 
-function dim(s: string): string {
-  if (chalk) return chalk.dim(s)
-  return s
-}
+const m = Deps()
+.add('chalk', () => require('chalk') as typeof Chalk)
+.add('util', () => require('./util') as typeof Util)
 
 export interface FlagUsageOptions { displayRequired?: boolean }
 export function flagUsage(flag: IFlag<any>, options: FlagUsageOptions = {}): [string, string | undefined] {
@@ -18,13 +18,14 @@ export function flagUsage(flag: IFlag<any>, options: FlagUsageOptions = {}): [st
 
   let description: string | undefined = flag.description || ''
   if (options.displayRequired && flag.required) description = `(required) ${description}`
-  description = description ? dim(description) : undefined
+  description = description ? m.chalk.dim(description) : undefined
 
   return [` ${label.join(',').trim()}${usage}`, description] as [string, string | undefined]
 }
 
 export function flagUsages(flags: IFlag<any>[], options: FlagUsageOptions = {}): [string, string | undefined][] {
   if (!flags.length) return []
+  const {sortBy} = m.util
   return sortBy(flags, f => [f.char ? -1 : 1, f.char, f.name])
   .map(f => flagUsage(f, options))
 }

src/index.ts

@@ -4,9 +4,13 @@ import * as args from './args'
 import {OutputArgs, OutputFlags, Parser, ParserOutput as Output} from './parse'
 export {args}
 import * as flags from './flags'
-import {validate} from './validate'
+import * as Validate from './validate'
 export {flags}
 export {flagUsages} from './help'
+import Deps from './deps'
+
+const m = Deps()
+.add('validate', () => require('./validate').validate as typeof Validate.validate)
 
 export type Input<TFlags extends flags.Output> = {
   flags?: flags.Input<TFlags>
@@ -30,7 +34,7 @@ export function parse<TFlags, TArgs extends {[name: string]: string}>(argv: stri
   }
   const parser = new Parser(input)
   const output = parser.parse()
-  validate({input, output})
+  m.validate({input, output})
   return output as any
 }
 

src/parse.ts

@@ -1,11 +1,14 @@
 // tslint:disable interface-over-type-literal
 
-import {CLIError} from '@oclif/errors'
-
 import {Arg} from './args'
+import Deps from './deps'
 import * as Errors from './errors'
 import * as Flags from './flags'
-import {pickBy} from './util'
+import * as Util from './util'
+
+const m = Deps()
+.add('errors', () => require('./errors') as typeof Errors)
+.add('util', () => require('./util') as typeof Util)
 
 let debug: any
 try {
@@ -45,6 +48,7 @@ export class Parser<T extends ParserInput, TFlags extends OutputFlags<T['flags']
   private readonly booleanFlags: { [k: string]: Flags.IBooleanFlag<any> }
   private readonly context: any
   constructor(private readonly input: T) {
+    const {pickBy} = m.util
     this.context = input.context || {}
     this.argv = input.argv.slice(0)
     this._setNames()
@@ -95,7 +99,7 @@ export class Parser<T extends ParserInput, TFlags extends OutputFlags<T['flags']
           input = arg.slice(arg[2] === '=' ? 3 : 2)
         }
         if (!input) {
-          throw new CLIError(`Flag --${name} expects a value`)
+          throw new m.errors.CLIError(`Flag --${name} expects a value`)
         }
         this.raw.push({type: 'flag', flag: flag.name, input})
       } else {
@@ -151,7 +155,7 @@ export class Parser<T extends ParserInput, TFlags extends OutputFlags<T['flags']
     const flags = {} as any
     for (const token of this._flagTokens) {
       const flag = this.input.flags[token.flag]
-      if (!flag) throw new CLIError(`Unexpected flag ${token.flag}`)
+      if (!flag) throw new m.errors.CLIError(`Unexpected flag ${token.flag}`)
       if (flag.type === 'boolean') {
         if (token.input === `--no-${flag.name}`) {
           flags[token.flag] = false
@@ -162,7 +166,7 @@ export class Parser<T extends ParserInput, TFlags extends OutputFlags<T['flags']
       } else {
         const input = token.input
         if (flag.options && !flag.options.includes(input)) {
-          throw new Errors.FlagInvalidOptionError(flag, input)
+          throw new m.errors.FlagInvalidOptionError(flag, input)
         }
         const value = flag.parse ? flag.parse(input, this.context) : input
         if (flag.multiple) {
@@ -200,7 +204,7 @@ export class Parser<T extends ParserInput, TFlags extends OutputFlags<T['flags']
       if (token) {
         if (arg) {
           if (arg.options && !arg.options.includes(token.input)) {
-            throw new Errors.ArgInvalidOptionError(arg, token.input)
+            throw new m.errors.ArgInvalidOptionError(arg, token.input)
           }
           args[i] = arg.parse(token.input)
         } else {

yarn.lock

@@ -6,9 +6,9 @@
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/@heroku/linewrap/-/linewrap-1.0.0.tgz#a9d4e99f0a3e423a899b775f5f3d6747a1ff15c6"
 
-"@oclif/errors@^1.0.3":
-  version "1.0.3"
-  resolved "https://registry.yarnpkg.com/@oclif/errors/-/errors-1.0.3.tgz#f23c024075855c7d116d041ee158f99bd51175af"
+"@oclif/errors@^1.0.4":
+  version "1.0.4"
+  resolved "https://registry.yarnpkg.com/@oclif/errors/-/errors-1.0.4.tgz#8e34386ede530484ae3c98bc21d818c416214c66"
   dependencies:
     clean-stack "^1.3.0"
     fs-extra "^5.0.0"