From b40bef48631a07ac8977b090354ece203f9dd7f7 Mon Sep 17 00:00:00 2001
From: Jonathan Clem <jclem@github.com>
Date: Wed, 22 May 2019 12:34:57 -0400
Subject: [PATCH 1/2] Use an option for setting `mkdirP`'s max loop size

- No need to dirty up the environment
- Use a jest pattern for expecting the right error/assertion count
---
 packages/io/__tests__/io.test.ts | 10 ++++------
 packages/io/src/io.ts            |  8 ++++++--
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/packages/io/__tests__/io.test.ts b/packages/io/__tests__/io.test.ts
index ddaedded65..2bdb5aaac2 100644
--- a/packages/io/__tests__/io.test.ts
+++ b/packages/io/__tests__/io.test.ts
@@ -807,14 +807,12 @@ describe('mkdirP', () => {
       '9',
       '10'
     )
-    process.env['TEST_MKDIRP_FAILSAFE'] = '10'
+
+    expect.assertions(1)
+
     try {
-      await io.mkdirP(testPath)
-      throw new Error('directory should not have been created')
+      await io.mkdirP(testPath, {loopMax: 10})
     } catch (err) {
-      delete process.env['TEST_MKDIRP_FAILSAFE']
-
-      // ENOENT is expected, all other errors are not
       expect(err.code).toBe('ENOENT')
     }
   })
diff --git a/packages/io/src/io.ts b/packages/io/src/io.ts
index a1f44bea04..72cedda2a7 100644
--- a/packages/io/src/io.ts
+++ b/packages/io/src/io.ts
@@ -99,9 +99,13 @@ export async function rmRF(inputPath: string): Promise<void> {
  * Will throw if it fails
  *
  * @param   fsPath        path to create
+ * @param   options       options for configuring the mkdirP call. For testing.
  * @returns Promise<void>
  */
-export async function mkdirP(fsPath: string): Promise<void> {
+export async function mkdirP(
+  fsPath: string,
+  {loopMax}: {loopMax: number} = {loopMax: 1000}
+): Promise<void> {
   if (!fsPath) {
     throw new Error('Parameter p is required')
   }
@@ -113,7 +117,7 @@ export async function mkdirP(fsPath: string): Promise<void> {
   // eslint-disable-next-line no-constant-condition
   while (true) {
     // validate the loop is not out of control
-    if (stack.length >= (process.env['TEST_MKDIRP_FAILSAFE'] || 1000)) {
+    if (stack.length >= loopMax) {
       // let the framework throw
       await ioUtil.mkdir(fsPath)
       return

From 7f1966b00807758030a2a8841fa791570c787bef Mon Sep 17 00:00:00 2001
From: Jonathan Clem <jclem@github.com>
Date: Wed, 22 May 2019 12:36:11 -0400
Subject: [PATCH 2/2] Comment is redundant with variable name

---
 packages/io/src/io.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/packages/io/src/io.ts b/packages/io/src/io.ts
index 72cedda2a7..84b7e19df9 100644
--- a/packages/io/src/io.ts
+++ b/packages/io/src/io.ts
@@ -116,7 +116,6 @@ export async function mkdirP(
 
   // eslint-disable-next-line no-constant-condition
   while (true) {
-    // validate the loop is not out of control
     if (stack.length >= loopMax) {
       // let the framework throw
       await ioUtil.mkdir(fsPath)