ci: Fix a couple of memory leaks in test setups

packages/client/src/runtime/getPrismaClient.ts

@@ -1,5 +1,5 @@
 import { Context, context } from '@opentelemetry/api'
-import Debug from '@prisma/debug'
+import Debug, { clearLogs } from '@prisma/debug'
 import {
   BatchTransactionOptions,
   BinaryEngine,
@@ -591,6 +591,11 @@ export function getPrismaClient(config: GetPrismaClientConfig) {
         e.clientVersion = this._clientVersion
         throw e
       } finally {
+        // Debug module keeps a list of last 100 logs regardless of environment variables.
+        // This can cause a memory leak. It's especially bad in jest environment where keeping an
+        // error in this list will prevent jest sandbox from being GCed. Clearing logs on disconnect
+        // helps to avoid that
+        clearLogs()
         if (!this._dataProxy) {
           this._dmmf = undefined
         }

packages/client/tests/functional/jest.config.js

@@ -1,10 +1,21 @@
 'use strict'
 const os = require('os')
+const path = require('path')
+
+const runtimeDir = path.dirname(require.resolve('../../runtime'))
+const packagesDir = path.resolve('..', '..', '..')
 
 module.exports = () => {
   const configCommon = {
     testMatch: ['**/*.ts', '!(**/*.d.ts)', '!(**/_utils/**)', '!(**/_*.ts)', '!(**/.generated/**)'],
-    transformIgnorePatterns: [],
+    // By default, jest passes every file it loads thorough a transform and caches result both on disk and in memory
+    // That includes all generated clients as well. So, unless we ignore them, they'd be kept in memory until test process
+    // is finished, even though they are needed for 1 test only
+    transformIgnorePatterns: [
+      '[\\/]node_modules[\\/]',
+      escapeRegex(runtimeDir),
+      `${escapeRegex(packagesDir)}[\\/][^\\/]+[\\/]dist[\\/]`,
+    ],
     reporters: [
       'default',
       [
@@ -47,3 +58,12 @@ module.exports = () => {
     },
   }
 }
+
+/**
+ * https://stackoverflow.com/a/6969486
+ * @param {string} str
+ * @returns {string}
+ */
+function escapeRegex(str) {
+  return str.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')
+}

packages/debug/src/index.ts

@@ -81,5 +81,9 @@ export function getLogs(numChars = 7500): string {
   return output.slice(-numChars)
 }
 
+export function clearLogs() {
+  debugArgsHistory.length = 0
+}
+
 export { Debug }
 export default Debug