ci: fix jest memory flakiness (#18859)

packages/client/package.json

@@ -65,6 +65,7 @@
     "@codspeed/benchmark.js-plugin": "1.0.2",
     "@faker-js/faker": "7.6.0",
     "@fast-check/jest": "1.6.0",
+    "@jest/create-cache-key-function": "29.5.0",
     "@jest/globals": "29.4.3",
     "@jest/test-sequencer": "29.4.3",
     "@opentelemetry/api": "1.4.0",

packages/client/tests/functional/esbuild-transformer.js

@@ -0,0 +1,67 @@
+const fs = require('fs')
+
+const esbuild = require('esbuild')
+const getCacheKeyFunction = require('@jest/create-cache-key-function').default
+
+const nodeVersion = process.version.match(/v(\d+)/)[1] || '14'
+const cacheKeyFunction = getCacheKeyFunction([], ['v1', nodeVersion])
+
+function needsTranspilation(contents, filename) {
+  if (filename.endsWith('.ts') === true) {
+    return true
+  }
+
+  if (filename.endsWith('.mjs') === true) {
+    return true
+  }
+
+  if (contents.includes('require(') === true) {
+    return false
+  }
+
+  if (contents.includes('module.exports') === true) {
+    return false
+  }
+
+  if (contents.includes('exports.') === true) {
+    return false
+  }
+
+  return true
+}
+
+const transformer = {
+  getCacheKey(contents, filename, ...rest) {
+    return cacheKeyFunction(filename, fs.statSync(filename).mtimeMs.toString(), ...rest)
+  },
+  process(_content, filename, { transformerConfig }) {
+    if (needsTranspilation(_content, filename) === true) {
+      return esbuild.transformSync(_content, {
+        sourcesContent: true,
+        minify: false,
+        sourcefile: filename,
+        loader: 'ts',
+        format: 'cjs',
+        platform: 'node',
+        target: `node${nodeVersion}`,
+        keepNames: true,
+        logLevel: 'error',
+        sourcemap: true,
+        ...transformerConfig,
+      })
+    }
+
+    try {
+      return {
+        code: _content,
+        map: fs.readFileSync(`${filename}.map`, 'utf8'),
+      }
+    } catch (e) {}
+
+    return {
+      code: _content,
+    }
+  },
+}
+
+module.exports = transformer

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

@@ -1,23 +1,12 @@
 'use strict'
 const os = require('os')
-const path = require('path')
-
-const packagesDir = path.resolve(__dirname, '..', '..', '..')
-const runtimeDir = path.dirname(require.resolve('../../runtime'))
 
 const isMacOrWindowsCI = Boolean(process.env.CI) && ['darwin', 'win32'].includes(process.platform)
 
 module.exports = () => {
   const configCommon = {
     testMatch: ['**/*.ts', '!(**/*.d.ts)', '!(**/_utils/**)', '!(**/_*.ts)', '!(**/.generated/**)'],
-    // 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: [
-      '[\\.]generated[\\/]@prisma[\\/]client[\\/]',
-      escapeRegex(runtimeDir),
-      `${escapeRegex(packagesDir)}[\\/][^\\/]+[\\/]dist[\\/]`,
-    ],
+    transformIgnorePatterns: [],
     reporters: ['default'],
     globalSetup: './_utils/globalSetup.js',
     snapshotSerializers: ['@prisma/get-platform/src/test-utils/jestSnapshotSerializer'],
@@ -62,16 +51,7 @@ module.exports = () => {
   return {
     ...configCommon,
     transform: {
-      '^.+\\.(m?j|t)s$': '@swc/jest',
+      '^.+\\.(m?j|t)s$': ['./esbuild-transformer', {}],
     },
   }
 }
-
-/**
- * https://stackoverflow.com/a/6969486
- * @param {string} str
- * @returns {string}
- */
-function escapeRegex(str) {
-  return str.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')
-}