From 05ebca2c4c9ca0e43789c0348d6eab8bb40fa151 Mon Sep 17 00:00:00 2001
From: Thomas Rittson <31796059+eliykat@users.noreply.github.com>
Date: Thu, 8 Sep 2022 08:05:30 +1000
Subject: [PATCH] [EC-497] Fix memory leaks in tests (#3421)

* Add isolatedModules:true

* Add manual typechecking in CI for libs/ tests
---
 .github/workflows/test.yml      | 11 ++++++++++-
 jest.config.js                  |  9 +++++++++
 libs/shared/jest.config.base.js |  7 ++++++-
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 36e4157f05b..bb0b4453dfa 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -42,7 +42,16 @@ jobs:
       - name: Install Node dependencies
         run: npm ci
 
+      # We use isolatedModules: true which disables typechecking in tests
+      # Tests in apps/ are typechecked when their app is built, so we just do it here for libs/
+      # See https://bitwarden.atlassian.net/browse/EC-497
+      - name: Run typechecking
+        run: |
+          for p in libs/**/tsconfig.spec.json; do
+            echo "Typechecking $p"
+            npx tsc --noEmit --project $p
+          done
+
       - name: Run tests
         run: |
-          export NODE_OPTIONS=--max_old_space_size=6144
           npm run test
diff --git a/jest.config.js b/jest.config.js
index e8f4ce151d4..7a747974f53 100644
--- a/jest.config.js
+++ b/jest.config.js
@@ -26,4 +26,13 @@ module.exports = {
   // https://github.com/facebook/jest/issues/9430#issuecomment-1149882002
   // Also anecdotally improves performance when run locally
   maxWorkers: 3,
+  globals: {
+    "ts-jest": {
+      // Further workaround for memory leak, recommended here:
+      // https://github.com/kulshekhar/ts-jest/issues/1967#issuecomment-697494014
+      // Makes tests run faster and reduces size/rate of leak, but loses typechecking on test code
+      // See https://bitwarden.atlassian.net/browse/EC-497 for more info
+      isolatedModules: true,
+    },
+  },
 };
diff --git a/libs/shared/jest.config.base.js b/libs/shared/jest.config.base.js
index 7538064c284..056e54e9a7e 100644
--- a/libs/shared/jest.config.base.js
+++ b/libs/shared/jest.config.base.js
@@ -10,10 +10,15 @@ module.exports = {
   // Also anecdotally improves performance when run locally
   maxWorkers: 3,
 
-  // Jest does not use tsconfig.spec.json by default
   globals: {
     "ts-jest": {
+      // Jest does not use tsconfig.spec.json by default
       tsconfig: "<rootDir>/tsconfig.spec.json",
+      // Further workaround for memory leak, recommended here:
+      // https://github.com/kulshekhar/ts-jest/issues/1967#issuecomment-697494014
+      // Makes tests run faster and reduces size/rate of leak, but loses typechecking on test code
+      // See https://bitwarden.atlassian.net/browse/EC-497 for more info
+      isolatedModules: true,
     },
   },
 };