test: move common.ArrayStream to separate module

In a continuing effort to de-monolithize `require('../common')`,
move `common.ArrayStream` out to a separate module that is
imported only when it is needed.

PR-URL: https://github.com/nodejs/node/pull/22447
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

1 files changed, 14 insertions, 3 deletions

diff --git a/test/common/README.md b/test/common/README.md
index 27634c97e1..e44dcd299c 100644
--- a/test/common/README.md
+++ b/test/common/README.md
@@ -38,9 +38,6 @@ tasks.
 
 Takes `whitelist` and concats that with predefined `knownGlobals`.
 
-### arrayStream
-A stream to push an array into a REPL
-
 ### busyLoop(time)
 * `time` [<number>]
 
@@ -413,6 +410,20 @@ Platform normalizes the `pwd` command.
 
 Synchronous version of `spawnPwd`.
 
+## ArrayStream Module
+
+The `ArrayStream` module provides a simple `Stream` that pushes elements from
+a given array.
+
+<!-- eslint-disable no-undef, node-core/required-modules -->
+```js
+const ArrayStream = require('../common/arraystream');
+const stream = new ArrayStream();
+stream.run(['a', 'b', 'c']);
+```
+
+It can be used within tests as a simple mock stream.
+
 ## Countdown Module
 
 The `Countdown` module provides a simple countdown mechanism for tests that