Add some unit tests to codify assumptions

Signed-off-by: Sebastian Malton <sebastian@malton.name>

yarn.lock

@@ -2217,6 +2217,13 @@
   resolved "https://registry.yarnpkg.com/@types/md5-file/-/md5-file-4.0.2.tgz#c7241e88f4aa17218c774befb0fc34f33f21fe36"
   integrity sha512-8gacRfEqLrmZ6KofpFfxyjsm/LYepeWUWUJGaf5A9W9J5B2/dRZMdkDqFDL6YDa9IweH12IO76jO7mpsK2B3wg==
 
+"@types/memorystream@^0.3.0":
+  version "0.3.0"
+  resolved "https://registry.yarnpkg.com/@types/memorystream/-/memorystream-0.3.0.tgz#7616df4c42a479805d052a058d990b879d5e368f"
+  integrity sha512-gzh6mqZcLryYHn4g2MuMWjo9J1+Py/XYwITyZmUxV7ZoBIi7bTbBgSiuC5tcm3UL3gmaiYssQFDlXr/3fK94cw==
+  dependencies:
+    "@types/node" "*"
+
 "@types/mime@^1":
   version "1.3.2"
   resolved "https://registry.yarnpkg.com/@types/mime/-/mime-1.3.2.tgz#93e25bf9ee75fe0fd80b594bc4feb0e862111b5a"
@@ -8735,6 +8742,11 @@ memoize-one@^6.0.0:
   resolved "https://registry.yarnpkg.com/memoize-one/-/memoize-one-6.0.0.tgz#b2591b871ed82948aee4727dc6abceeeac8c1045"
   integrity sha512-rkpe71W0N0c0Xz6QD0eJETuWAJGnJ9afsl1srmwPrI+yBCkge5EycXXbYRyvL29zZVUWQCY7InPRCv3GDXuZNw==
 
+memorystream@^0.3.1:
+  version "0.3.1"
+  resolved "https://registry.yarnpkg.com/memorystream/-/memorystream-0.3.1.tgz#86d7090b30ce455d63fbae12dda51a47ddcaf9b2"
+  integrity sha512-S3UwM3yj5mtUSEfP41UZmt/0SCoVYUcU1rkXv+BQ5Ig8ndL4sPoJNBUJERafdPb5jjHJGuMgytgKvKIf58XNBw==
+
 merge-descriptors@1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/merge-descriptors/-/merge-descriptors-1.0.1.tgz#b00aaa556dd8b44568150ec9d1b953f3f90cbb61"