chore: reuse lodash memoize

package.json

@@ -59,6 +59,7 @@
     "bs-logger": "0.x",
     "buffer-from": "1.x",
     "fast-json-stable-stringify": "2.x",
+    "lodash.memoize": "4.x",
     "json5": "2.x",
     "make-error": "1.x",
     "mkdirp": "0.x",
@@ -103,7 +104,6 @@
     "jest": "24.x",
     "js-yaml": "latest",
     "lint-staged": "latest",
-    "lodash.memoize": "4.x",
     "lodash.merge": "4.x",
     "lodash.set": "4.x",
     "npm-run-all": "latest",

src/compiler.ts

@@ -33,6 +33,7 @@ import { LogContexts, LogLevels, Logger } from 'bs-logger'
 import bufferFrom = require('buffer-from')
 import stableStringify = require('fast-json-stable-stringify')
 import { readFileSync, writeFileSync } from 'fs'
+import memoize = require('lodash.memoize')
 import mkdirp = require('mkdirp')
 import { basename, extname, join, relative } from 'path'
 
@@ -226,22 +227,6 @@ export function createCompiler(configs: ConfigSet): TsCompiler {
   return { cwd, compile, getTypeInfo, extensions, cachedir, ts }
 }
 
-type AnyFn = (...args: any[]) => any
-function memoize<T extends AnyFn = AnyFn>(fn: T): T {
-  const cache = new Map()
-
-  return ((arg: string) => {
-    const entry = cache.get(arg)
-    if (entry !== undefined) {
-      return entry
-    }
-
-    const res = fn(arg)
-    cache.set(arg, res)
-    return res
-  }) as T
-}
-
 /**
  * Internal source output.
  */