From 95ef9766aafd9a01a4977e87bb817174c668f7bf Mon Sep 17 00:00:00 2001
From: Alexander Kachkaev <alexander@kachkaev.ru>
Date: Tue, 25 Oct 2022 00:32:57 +0100
Subject: [PATCH 01/23] Add failing test

---
 e2e/__tests__/nativeEsmWasm.test.ts          |  23 +++++++++++++++++++
 e2e/native-esm-wasm/__tests__/answer.test.js |  12 ++++++++++
 e2e/native-esm-wasm/answer.js                |  13 +++++++++++
 e2e/native-esm-wasm/answer.wasm              | Bin 0 -> 181 bytes
 e2e/native-esm-wasm/package.json             |   8 +++++++
 5 files changed, 56 insertions(+)
 create mode 100644 e2e/__tests__/nativeEsmWasm.test.ts
 create mode 100644 e2e/native-esm-wasm/__tests__/answer.test.js
 create mode 100644 e2e/native-esm-wasm/answer.js
 create mode 100644 e2e/native-esm-wasm/answer.wasm
 create mode 100644 e2e/native-esm-wasm/package.json

diff --git a/e2e/__tests__/nativeEsmWasm.test.ts b/e2e/__tests__/nativeEsmWasm.test.ts
new file mode 100644
index 000000000000..0d286cc8753b
--- /dev/null
+++ b/e2e/__tests__/nativeEsmWasm.test.ts
@@ -0,0 +1,23 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import {resolve} from 'path';
+import {json as runJest} from '../runJest';
+
+const DIR = resolve(__dirname, '../native-esm-wasm');
+
+test('runs WASM test with native ESM', () => {
+  const {exitCode, json} = runJest(DIR, [], {
+    nodeOptions:
+      '--experimental-vm-modules --experimental-wasm-modules --no-warnings',
+  });
+
+  expect(exitCode).toBe(0);
+
+  expect(json.numTotalTests).toBe(1);
+  expect(json.numPassedTests).toBe(1);
+});
diff --git a/e2e/native-esm-wasm/__tests__/answer.test.js b/e2e/native-esm-wasm/__tests__/answer.test.js
new file mode 100644
index 000000000000..c6e3cff1ae28
--- /dev/null
+++ b/e2e/native-esm-wasm/__tests__/answer.test.js
@@ -0,0 +1,12 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import {getAnswer} from '../answer';
+
+test('test answer', () => {
+  expect(getAnswer()).toBe(42);
+});
diff --git a/e2e/native-esm-wasm/answer.js b/e2e/native-esm-wasm/answer.js
new file mode 100644
index 000000000000..0fc6d243cb8a
--- /dev/null
+++ b/e2e/native-esm-wasm/answer.js
@@ -0,0 +1,13 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import * as wasm from './answer.wasm';
+
+export function getAnswer() {
+  const ret = wasm.getAnswer();
+  return ret;
+}
diff --git a/e2e/native-esm-wasm/answer.wasm b/e2e/native-esm-wasm/answer.wasm
new file mode 100644
index 0000000000000000000000000000000000000000..2dd107d7b789375eab071e611c0cae746f3b5c84
GIT binary patch
literal 181
zcmWNLy$*sf6h?2$kD@L*xS2452~7(IVdNEj0t;M;2^7;p2yyV$ZSqa$oZ$m$1_A)Y
zBTpbdhZ67{0>{mn`U4K5UMU0}PL(nXYJi<jT&S*l_y!+6wsV8p&}}bOH_Hx*`<TrH
z2df%12HT`w9Zy@<Tm;KA#>41VmqO+!?_tW*G~tC^>@Tvnna`Oh89yxcRZ_oI+o3vf
Qma-xXBdld!idR;|f3hts^Z)<=

literal 0
HcmV?d00001

diff --git a/e2e/native-esm-wasm/package.json b/e2e/native-esm-wasm/package.json
new file mode 100644
index 000000000000..3457bb63f174
--- /dev/null
+++ b/e2e/native-esm-wasm/package.json
@@ -0,0 +1,8 @@
+{
+  "type": "module",
+  "name": "native-esm-wasm",
+  "jest": {
+    "testEnvironment": "node",
+    "transform": {}
+  }
+}

From 645db88d64cd3ccb2ab053b955c0ca2cbe50f5bc Mon Sep 17 00:00:00 2001
From: Alexander Kachkaev <alexander@kachkaev.ru>
Date: Tue, 25 Oct 2022 00:34:25 +0100
Subject: [PATCH 02/23] Update `jest-runtime` to fix tests

---
 e2e/native-esm/__tests__/native-esm.test.js |  2 +-
 packages/jest-runtime/src/index.ts          | 63 +++++++++++++++++++--
 2 files changed, 60 insertions(+), 5 deletions(-)

diff --git a/e2e/native-esm/__tests__/native-esm.test.js b/e2e/native-esm/__tests__/native-esm.test.js
index 6403e741ac65..befe571a01d3 100644
--- a/e2e/native-esm/__tests__/native-esm.test.js
+++ b/e2e/native-esm/__tests__/native-esm.test.js
@@ -258,7 +258,7 @@ test('imports from "data:text/javascript" URI with invalid data fail', async ()
 test('imports from "data:application/wasm" URI not supported', async () => {
   await expect(() =>
     import('data:application/wasm,96cafe00babe'),
-  ).rejects.toThrow('WASM is currently not supported');
+  ).rejects.toThrow('WASM in data URLs is currently not supported');
 });
 
 test('supports imports from "data:application/json" URI', async () => {
diff --git a/packages/jest-runtime/src/index.ts b/packages/jest-runtime/src/index.ts
index 7be6cf2db53d..20d35f6df9e7 100644
--- a/packages/jest-runtime/src/index.ts
+++ b/packages/jest-runtime/src/index.ts
@@ -398,9 +398,12 @@ export default class Runtime {
 
   // unstable as it should be replaced by https://github.com/nodejs/modules/issues/393, and we don't want people to use it
   unstable_shouldLoadAsEsm(path: string): boolean {
-    return Resolver.unstable_shouldLoadAsEsm(
-      path,
-      this._config.extensionsToTreatAsEsm,
+    return (
+      path.endsWith('wasm') ||
+      Resolver.unstable_shouldLoadAsEsm(
+        path,
+        this._config.extensionsToTreatAsEsm,
+      )
     );
   }
 
@@ -441,6 +444,15 @@ export default class Runtime {
         'Promise initialization should be sync - please report this bug to Jest!',
       );
 
+      if (modulePath.endsWith('wasm')) {
+        const wasm = this._importWasmModule(modulePath, context);
+
+        this._esmoduleRegistry.set(cacheKey, wasm);
+
+        transformResolve();
+        return wasm;
+      }
+
       if (this._resolver.isCoreModule(modulePath)) {
         const core = this._importCoreModule(modulePath, context);
         this._esmoduleRegistry.set(cacheKey, core);
@@ -568,7 +580,7 @@ export default class Runtime {
 
       const mime = match.groups.mime;
       if (mime === 'application/wasm') {
-        throw new Error('WASM is currently not supported');
+        throw new Error('WASM in data URLs is currently not supported');
       }
 
       const encoding = match.groups.encoding;
@@ -1640,6 +1652,49 @@ export default class Runtime {
     return evaluateSyntheticModule(module);
   }
 
+  private async _importWasmModule(moduleName: string, context: VMContext) {
+    const wasmModule = await WebAssembly.compile(fs.readFileSync(moduleName));
+
+    const exports = WebAssembly.Module.exports(wasmModule);
+    const imports = WebAssembly.Module.imports(wasmModule);
+
+    const moduleLookup: Record<string, VMModule> = {};
+    for (const {module} of imports) {
+      if (moduleLookup[module] === undefined) {
+        moduleLookup[module] = await this.linkAndEvaluateModule(
+          await this.resolveModule(module, moduleName, context),
+        );
+      }
+    }
+
+    const syntheticModule = new SyntheticModule(
+      exports.map(({name}) => name),
+      function () {
+        const importsObject: WebAssembly.Imports = {};
+        for (const {module, name} of imports) {
+          if (!importsObject[module]) {
+            importsObject[module] = {};
+          }
+          importsObject[module][name] = moduleLookup[module].namespace[name];
+        }
+        const wasmInstance = new WebAssembly.Instance(
+          wasmModule,
+          importsObject,
+        );
+        for (const {name} of exports) {
+          // @ts-expect-error: TS doesn't know what `this` is
+          this.setExport(name, wasmInstance.exports[name]);
+        }
+      },
+      {
+        context,
+        identifier: moduleName,
+      },
+    );
+
+    return syntheticModule;
+  }
+
   private _getMockedNativeModule(): typeof nativeModule.Module {
     if (this._moduleImplementation) {
       return this._moduleImplementation;

From 99851798a9f4429592dcba7ffe13d27444c611f7 Mon Sep 17 00:00:00 2001
From: Alexander Kachkaev <alexander@kachkaev.ru>
Date: Thu, 27 Oct 2022 22:43:06 +0100
Subject: [PATCH 03/23] Support data:application/wasm imports

---
 .../__snapshots__/nativeEsm.test.ts.snap      |   2 +-
 e2e/__tests__/nativeEsmWasm.test.ts           |   4 +-
 e2e/native-esm-wasm/__tests__/answer.test.js  |  29 ++++-
 e2e/native-esm-wasm/answer.js                 |  13 --
 e2e/native-esm/__tests__/native-esm.test.js   |   6 -
 packages/jest-runtime/src/index.ts            | 122 ++++++++++--------
 6 files changed, 99 insertions(+), 77 deletions(-)
 delete mode 100644 e2e/native-esm-wasm/answer.js

diff --git a/e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap b/e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap
index 4324b26d16c4..1e6cd80fa82e 100644
--- a/e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap
+++ b/e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap
@@ -10,7 +10,7 @@ Ran all test suites matching /native-esm-deep-cjs-reexport.test.js/i."
 
 exports[`runs test with native ESM 1`] = `
 "Test Suites: 1 passed, 1 total
-Tests:       34 passed, 34 total
+Tests:       33 passed, 33 total
 Snapshots:   0 total
 Time:        <<REPLACED>>
 Ran all test suites matching /native-esm.test.js/i."
diff --git a/e2e/__tests__/nativeEsmWasm.test.ts b/e2e/__tests__/nativeEsmWasm.test.ts
index 0d286cc8753b..e19e4454fe70 100644
--- a/e2e/__tests__/nativeEsmWasm.test.ts
+++ b/e2e/__tests__/nativeEsmWasm.test.ts
@@ -18,6 +18,6 @@ test('runs WASM test with native ESM', () => {
 
   expect(exitCode).toBe(0);
 
-  expect(json.numTotalTests).toBe(1);
-  expect(json.numPassedTests).toBe(1);
+  expect(json.numTotalTests).toBe(4);
+  expect(json.numPassedTests).toBe(4);
 });
diff --git a/e2e/native-esm-wasm/__tests__/answer.test.js b/e2e/native-esm-wasm/__tests__/answer.test.js
index c6e3cff1ae28..5773887e3b5a 100644
--- a/e2e/native-esm-wasm/__tests__/answer.test.js
+++ b/e2e/native-esm-wasm/__tests__/answer.test.js
@@ -5,8 +5,33 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {getAnswer} from '../answer';
+// the point here is that it's the node core module
+// eslint-disable-next-line no-restricted-imports
+import {readFileSync} from 'fs';
+// The file was generated by wasm-pack
+import {getAnswer} from '../answer.wasm';
 
-test('test answer', () => {
+const wasmFileBuffer = readFileSync('answer.wasm');
+
+test('supports native wasm imports', () => {
   expect(getAnswer()).toBe(42);
 });
+
+test('supports imports from "data:application/wasm" URI with base64 encoding', async () => {
+  const importedWasmModule = await import(
+    `data:application/wasm;base64,${wasmFileBuffer.toString('base64')}`
+  );
+  expect(importedWasmModule.getAnswer()).toBe(42);
+});
+
+test('imports from "data:text/wasm" URI without explicit encoding fail', async () => {
+  await expect(() =>
+    import(`data:application/wasm,${wasmFileBuffer.toString('base64')}`),
+  ).rejects.toThrow('Missing data URI encoding');
+});
+
+test('imports from "data:text/wasm" URI with invalid encoding fail', async () => {
+  await expect(() =>
+    import(`data:application/wasm,hex,${wasmFileBuffer.toString('hex')}`),
+  ).rejects.toThrow('Missing data URI encoding');
+});
diff --git a/e2e/native-esm-wasm/answer.js b/e2e/native-esm-wasm/answer.js
deleted file mode 100644
index 0fc6d243cb8a..000000000000
--- a/e2e/native-esm-wasm/answer.js
+++ /dev/null
@@ -1,13 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-import * as wasm from './answer.wasm';
-
-export function getAnswer() {
-  const ret = wasm.getAnswer();
-  return ret;
-}
diff --git a/e2e/native-esm/__tests__/native-esm.test.js b/e2e/native-esm/__tests__/native-esm.test.js
index befe571a01d3..4b253fe6bca1 100644
--- a/e2e/native-esm/__tests__/native-esm.test.js
+++ b/e2e/native-esm/__tests__/native-esm.test.js
@@ -255,12 +255,6 @@ test('imports from "data:text/javascript" URI with invalid data fail', async ()
   ).rejects.toThrow("Unexpected token '.'");
 });
 
-test('imports from "data:application/wasm" URI not supported', async () => {
-  await expect(() =>
-    import('data:application/wasm,96cafe00babe'),
-  ).rejects.toThrow('WASM in data URLs is currently not supported');
-});
-
 test('supports imports from "data:application/json" URI', async () => {
   const data = await import('data:application/json,{"foo": "bar"}');
   expect(data.default).toEqual({foo: 'bar'});
diff --git a/packages/jest-runtime/src/index.ts b/packages/jest-runtime/src/index.ts
index 20d35f6df9e7..195149a07941 100644
--- a/packages/jest-runtime/src/index.ts
+++ b/packages/jest-runtime/src/index.ts
@@ -445,7 +445,11 @@ export default class Runtime {
       );
 
       if (modulePath.endsWith('wasm')) {
-        const wasm = this._importWasmModule(modulePath, context);
+        const wasm = this._importWasmModule(
+          fs.readFileSync(modulePath),
+          modulePath,
+          context,
+        );
 
         this._esmoduleRegistry.set(cacheKey, wasm);
 
@@ -579,56 +583,67 @@ export default class Runtime {
       }
 
       const mime = match.groups.mime;
-      if (mime === 'application/wasm') {
-        throw new Error('WASM in data URLs is currently not supported');
-      }
-
       const encoding = match.groups.encoding;
-      let code = match.groups.code;
-      if (!encoding || encoding === 'charset=utf-8') {
-        code = decodeURIComponent(code);
-      } else if (encoding === 'base64') {
-        code = Buffer.from(code, 'base64').toString();
-      } else {
-        throw new Error(`Invalid data URI encoding: ${encoding}`);
-      }
-
       let module;
-      if (mime === 'application/json') {
-        module = new SyntheticModule(
-          ['default'],
-          function () {
-            const obj = JSON.parse(code);
-            // @ts-expect-error: TS doesn't know what `this` is
-            this.setExport('default', obj);
-          },
-          {context, identifier: specifier},
+
+      if (mime === 'application/wasm') {
+        if (!encoding) {
+          throw new Error('Missing data URI encoding');
+        }
+        if (encoding !== 'base64') {
+          throw new Error(`Invalid data URI encoding: ${encoding}`);
+        }
+        module = await this._importWasmModule(
+          Buffer.from(match.groups.code, 'base64'),
+          specifier,
+          context,
         );
       } else {
-        module = new SourceTextModule(code, {
-          context,
-          identifier: specifier,
-          importModuleDynamically: async (
-            specifier: string,
-            referencingModule: VMModule,
-          ) => {
-            invariant(
-              runtimeSupportsVmModules,
-              'You need to run with a version of node that supports ES Modules in the VM API. See https://jestjs.io/docs/ecmascript-modules',
-            );
-            const module = await this.resolveModule(
-              specifier,
-              referencingModule.identifier,
-              referencingModule.context,
-            );
+        let code = match.groups.code;
+        if (!encoding || encoding === 'charset=utf-8') {
+          code = decodeURIComponent(code);
+        } else if (encoding === 'base64') {
+          code = Buffer.from(code, 'base64').toString();
+        } else {
+          throw new Error(`Invalid data URI encoding: ${encoding}`);
+        }
 
-            return this.linkAndEvaluateModule(module);
-          },
-          initializeImportMeta(meta: ImportMeta) {
-            // no `jest` here as it's not loaded in a file
-            meta.url = specifier;
-          },
-        });
+        if (mime === 'application/json') {
+          module = new SyntheticModule(
+            ['default'],
+            function () {
+              const obj = JSON.parse(code);
+              // @ts-expect-error: TS doesn't know what `this` is
+              this.setExport('default', obj);
+            },
+            {context, identifier: specifier},
+          );
+        } else {
+          module = new SourceTextModule(code, {
+            context,
+            identifier: specifier,
+            importModuleDynamically: async (
+              specifier: string,
+              referencingModule: VMModule,
+            ) => {
+              invariant(
+                runtimeSupportsVmModules,
+                'You need to run with a version of node that supports ES Modules in the VM API. See https://jestjs.io/docs/ecmascript-modules',
+              );
+              const module = await this.resolveModule(
+                specifier,
+                referencingModule.identifier,
+                referencingModule.context,
+              );
+
+              return this.linkAndEvaluateModule(module);
+            },
+            initializeImportMeta(meta: ImportMeta) {
+              // no `jest` here as it's not loaded in a file
+              meta.url = specifier;
+            },
+          });
+        }
       }
 
       this._esmoduleRegistry.set(specifier, module);
@@ -1652,8 +1667,12 @@ export default class Runtime {
     return evaluateSyntheticModule(module);
   }
 
-  private async _importWasmModule(moduleName: string, context: VMContext) {
-    const wasmModule = await WebAssembly.compile(fs.readFileSync(moduleName));
+  private async _importWasmModule(
+    source: Buffer,
+    identifier: string,
+    context: VMContext,
+  ) {
+    const wasmModule = await WebAssembly.compile(source);
 
     const exports = WebAssembly.Module.exports(wasmModule);
     const imports = WebAssembly.Module.imports(wasmModule);
@@ -1662,7 +1681,7 @@ export default class Runtime {
     for (const {module} of imports) {
       if (moduleLookup[module] === undefined) {
         moduleLookup[module] = await this.linkAndEvaluateModule(
-          await this.resolveModule(module, moduleName, context),
+          await this.resolveModule(module, identifier, context),
         );
       }
     }
@@ -1686,10 +1705,7 @@ export default class Runtime {
           this.setExport(name, wasmInstance.exports[name]);
         }
       },
-      {
-        context,
-        identifier: moduleName,
-      },
+      {context, identifier},
     );
 
     return syntheticModule;

From 5d73f9a63b65dadb002c9bb28495298661b7ed8f Mon Sep 17 00:00:00 2001
From: Alexander Kachkaev <alexander@kachkaev.ru>
Date: Thu, 27 Oct 2022 22:45:20 +0100
Subject: [PATCH 04/23] Run tests twice (with and without
 --experimental-wasm-modules)

---
 e2e/__tests__/nativeEsmWasm.test.ts | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/e2e/__tests__/nativeEsmWasm.test.ts b/e2e/__tests__/nativeEsmWasm.test.ts
index e19e4454fe70..4b5c2ad313ec 100644
--- a/e2e/__tests__/nativeEsmWasm.test.ts
+++ b/e2e/__tests__/nativeEsmWasm.test.ts
@@ -11,6 +11,17 @@ import {json as runJest} from '../runJest';
 const DIR = resolve(__dirname, '../native-esm-wasm');
 
 test('runs WASM test with native ESM', () => {
+  const {exitCode, json} = runJest(DIR, [], {
+    nodeOptions: '--experimental-vm-modules --no-warnings',
+  });
+
+  expect(exitCode).toBe(0);
+
+  expect(json.numTotalTests).toBe(4);
+  expect(json.numPassedTests).toBe(4);
+});
+
+test('runs WASM test with native ESM with --experimental-wasm-modules flag', () => {
   const {exitCode, json} = runJest(DIR, [], {
     nodeOptions:
       '--experimental-vm-modules --experimental-wasm-modules --no-warnings',

From 734bbc5448d7dac58f8fc6459abe54fd729d6ffe Mon Sep 17 00:00:00 2001
From: Alexander Kachkaev <alexander@kachkaev.ru>
Date: Thu, 27 Oct 2022 22:51:47 +0100
Subject: [PATCH 05/23] Cover more rows

---
 e2e/native-esm-wasm/__tests__/answer.test.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/e2e/native-esm-wasm/__tests__/answer.test.js b/e2e/native-esm-wasm/__tests__/answer.test.js
index 5773887e3b5a..5d3771c7c8b5 100644
--- a/e2e/native-esm-wasm/__tests__/answer.test.js
+++ b/e2e/native-esm-wasm/__tests__/answer.test.js
@@ -32,6 +32,6 @@ test('imports from "data:text/wasm" URI without explicit encoding fail', async (
 
 test('imports from "data:text/wasm" URI with invalid encoding fail', async () => {
   await expect(() =>
-    import(`data:application/wasm,hex,${wasmFileBuffer.toString('hex')}`),
-  ).rejects.toThrow('Missing data URI encoding');
+    import('data:application/wasm;charset=utf-8,oops'),
+  ).rejects.toThrow('Invalid data URI encoding: charset=utf-8');
 });

From 612d480b9147eed811246058731f7706d01c9814 Mon Sep 17 00:00:00 2001
From: Alexander Kachkaev <alexander@kachkaev.ru>
Date: Thu, 27 Oct 2022 23:03:10 +0100
Subject: [PATCH 06/23] Add CHANGELOG entry

---
 CHANGELOG.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 494e36427afb..1721be9a79ae 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ### Features
 
+- `[jest-runtime]` Support WASM imports ([#13505](https://github.com/facebook/jest/pull/13505))
+
 ### Fixes
 
 - `[jest-mock]` Treat cjs modules as objects so they can be mocked ([#13513](https://github.com/facebook/jest/pull/13513))

From dcff11e50e14934e548c2b08e8b45cb5e91968dd Mon Sep 17 00:00:00 2001
From: Alexander Kachkaev <alexander@kachkaev.ru>
Date: Thu, 27 Oct 2022 23:16:19 +0100
Subject: [PATCH 07/23] Simplify tests

---
 .../__snapshots__/nativeEsm.test.ts.snap      |   8 +++++
 e2e/__tests__/nativeEsm.test.ts               |  12 +++++++
 e2e/__tests__/nativeEsmWasm.test.ts           |  34 ------------------
 .../answer.wasm => native-esm/42.wasm}        | Bin
 .../__tests__/native-esm-wasm.test.js}        |   4 +--
 5 files changed, 22 insertions(+), 36 deletions(-)
 delete mode 100644 e2e/__tests__/nativeEsmWasm.test.ts
 rename e2e/{native-esm-wasm/answer.wasm => native-esm/42.wasm} (100%)
 rename e2e/{native-esm-wasm/__tests__/answer.test.js => native-esm/__tests__/native-esm-wasm.test.js} (92%)

diff --git a/e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap b/e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap
index 1e6cd80fa82e..648efbfd14c9 100644
--- a/e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap
+++ b/e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap
@@ -8,6 +8,14 @@ Time:        <<REPLACED>>
 Ran all test suites matching /native-esm-deep-cjs-reexport.test.js/i."
 `;
 
+exports[`runs WASM test with native ESM 1`] = `
+"Test Suites: 1 passed, 1 total
+Tests:       4 passed, 4 total
+Snapshots:   0 total
+Time:        <<REPLACED>>
+Ran all test suites matching /native-esm-wasm.test.js/i."
+`;
+
 exports[`runs test with native ESM 1`] = `
 "Test Suites: 1 passed, 1 total
 Tests:       33 passed, 33 total
diff --git a/e2e/__tests__/nativeEsm.test.ts b/e2e/__tests__/nativeEsm.test.ts
index a636fdf1344a..f5227089c623 100644
--- a/e2e/__tests__/nativeEsm.test.ts
+++ b/e2e/__tests__/nativeEsm.test.ts
@@ -67,3 +67,15 @@ onNodeVersions('>=16.9.0', () => {
     expect(exitCode).toBe(0);
   });
 });
+
+test('runs WASM test with native ESM', () => {
+  const {exitCode, stderr, stdout} = runJest(DIR, ['native-esm-wasm.test.js'], {
+    nodeOptions: '--experimental-vm-modules --no-warnings',
+  });
+
+  const {summary} = extractSummary(stderr);
+
+  expect(summary).toMatchSnapshot();
+  expect(stdout).toBe('');
+  expect(exitCode).toBe(0);
+});
diff --git a/e2e/__tests__/nativeEsmWasm.test.ts b/e2e/__tests__/nativeEsmWasm.test.ts
deleted file mode 100644
index 4b5c2ad313ec..000000000000
--- a/e2e/__tests__/nativeEsmWasm.test.ts
+++ /dev/null
@@ -1,34 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-import {resolve} from 'path';
-import {json as runJest} from '../runJest';
-
-const DIR = resolve(__dirname, '../native-esm-wasm');
-
-test('runs WASM test with native ESM', () => {
-  const {exitCode, json} = runJest(DIR, [], {
-    nodeOptions: '--experimental-vm-modules --no-warnings',
-  });
-
-  expect(exitCode).toBe(0);
-
-  expect(json.numTotalTests).toBe(4);
-  expect(json.numPassedTests).toBe(4);
-});
-
-test('runs WASM test with native ESM with --experimental-wasm-modules flag', () => {
-  const {exitCode, json} = runJest(DIR, [], {
-    nodeOptions:
-      '--experimental-vm-modules --experimental-wasm-modules --no-warnings',
-  });
-
-  expect(exitCode).toBe(0);
-
-  expect(json.numTotalTests).toBe(4);
-  expect(json.numPassedTests).toBe(4);
-});
diff --git a/e2e/native-esm-wasm/answer.wasm b/e2e/native-esm/42.wasm
similarity index 100%
rename from e2e/native-esm-wasm/answer.wasm
rename to e2e/native-esm/42.wasm
diff --git a/e2e/native-esm-wasm/__tests__/answer.test.js b/e2e/native-esm/__tests__/native-esm-wasm.test.js
similarity index 92%
rename from e2e/native-esm-wasm/__tests__/answer.test.js
rename to e2e/native-esm/__tests__/native-esm-wasm.test.js
index 5d3771c7c8b5..17d4f4700823 100644
--- a/e2e/native-esm-wasm/__tests__/answer.test.js
+++ b/e2e/native-esm/__tests__/native-esm-wasm.test.js
@@ -9,9 +9,9 @@
 // eslint-disable-next-line no-restricted-imports
 import {readFileSync} from 'fs';
 // The file was generated by wasm-pack
-import {getAnswer} from '../answer.wasm';
+import {getAnswer} from '../42.wasm';
 
-const wasmFileBuffer = readFileSync('answer.wasm');
+const wasmFileBuffer = readFileSync('42.wasm');
 
 test('supports native wasm imports', () => {
   expect(getAnswer()).toBe(42);

From e524e409aa1aca35fe404f1793b88f44110640be Mon Sep 17 00:00:00 2001
From: Alexander Kachkaev <alexander@kachkaev.ru>
Date: Thu, 27 Oct 2022 23:23:45 +0100
Subject: [PATCH 08/23] Improve `path.endsWith`

---
 packages/jest-runtime/src/index.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/jest-runtime/src/index.ts b/packages/jest-runtime/src/index.ts
index 195149a07941..284be823c23b 100644
--- a/packages/jest-runtime/src/index.ts
+++ b/packages/jest-runtime/src/index.ts
@@ -399,7 +399,7 @@ export default class Runtime {
   // unstable as it should be replaced by https://github.com/nodejs/modules/issues/393, and we don't want people to use it
   unstable_shouldLoadAsEsm(path: string): boolean {
     return (
-      path.endsWith('wasm') ||
+      path.endsWith('.wasm') ||
       Resolver.unstable_shouldLoadAsEsm(
         path,
         this._config.extensionsToTreatAsEsm,
@@ -444,7 +444,7 @@ export default class Runtime {
         'Promise initialization should be sync - please report this bug to Jest!',
       );
 
-      if (modulePath.endsWith('wasm')) {
+      if (modulePath.endsWith('.wasm')) {
         const wasm = this._importWasmModule(
           fs.readFileSync(modulePath),
           modulePath,

From 08c890602871ae84962c89190bab48abe0a721fd Mon Sep 17 00:00:00 2001
From: Alexander Kachkaev <alexander@kachkaev.ru>
Date: Thu, 27 Oct 2022 23:24:39 +0100
Subject: [PATCH 09/23] Delete unused file

---
 e2e/native-esm-wasm/package.json | 8 --------
 1 file changed, 8 deletions(-)
 delete mode 100644 e2e/native-esm-wasm/package.json

diff --git a/e2e/native-esm-wasm/package.json b/e2e/native-esm-wasm/package.json
deleted file mode 100644
index 3457bb63f174..000000000000
--- a/e2e/native-esm-wasm/package.json
+++ /dev/null
@@ -1,8 +0,0 @@
-{
-  "type": "module",
-  "name": "native-esm-wasm",
-  "jest": {
-    "testEnvironment": "node",
-    "transform": {}
-  }
-}

From 66c8312df60b2ab96b22cbd94629285fdbac08d6 Mon Sep 17 00:00:00 2001
From: Alexander Kachkaev <alexander@kachkaev.ru>
Date: Fri, 28 Oct 2022 00:06:01 +0100
Subject: [PATCH 10/23] Make changelog phrase more explicit

---
 CHANGELOG.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1721be9a79ae..1411ae431a2a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,7 @@
 
 ### Features
 
-- `[jest-runtime]` Support WASM imports ([#13505](https://github.com/facebook/jest/pull/13505))
+- `[jest-runtime]` Support WASM imports in ESM modules ([#13505](https://github.com/facebook/jest/pull/13505))
 
 ### Fixes
 

From 6586a24c9016ef3073ac92acd2b3f9c312c40c5d Mon Sep 17 00:00:00 2001
From: Alexander Kachkaev <alexander@kachkaev.ru>
Date: Fri, 28 Oct 2022 00:11:46 +0100
Subject: [PATCH 11/23] Fix Wasm casing

---
 CHANGELOG.md                                       | 2 +-
 e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap | 2 +-
 e2e/__tests__/nativeEsm.test.ts                    | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1411ae431a2a..66f632af4cb3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,7 @@
 
 ### Features
 
-- `[jest-runtime]` Support WASM imports in ESM modules ([#13505](https://github.com/facebook/jest/pull/13505))
+- `[jest-runtime]` Support Wasm imports in ESM modules ([#13505](https://github.com/facebook/jest/pull/13505))
 
 ### Fixes
 
diff --git a/e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap b/e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap
index 648efbfd14c9..a9d283f5e7e1 100644
--- a/e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap
+++ b/e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap
@@ -8,7 +8,7 @@ Time:        <<REPLACED>>
 Ran all test suites matching /native-esm-deep-cjs-reexport.test.js/i."
 `;
 
-exports[`runs WASM test with native ESM 1`] = `
+exports[`runs Wasm test with native ESM 1`] = `
 "Test Suites: 1 passed, 1 total
 Tests:       4 passed, 4 total
 Snapshots:   0 total
diff --git a/e2e/__tests__/nativeEsm.test.ts b/e2e/__tests__/nativeEsm.test.ts
index f5227089c623..dd0078af63c7 100644
--- a/e2e/__tests__/nativeEsm.test.ts
+++ b/e2e/__tests__/nativeEsm.test.ts
@@ -68,7 +68,7 @@ onNodeVersions('>=16.9.0', () => {
   });
 });
 
-test('runs WASM test with native ESM', () => {
+test('runs Wasm test with native ESM', () => {
   const {exitCode, stderr, stdout} = runJest(DIR, ['native-esm-wasm.test.js'], {
     nodeOptions: '--experimental-vm-modules --no-warnings',
   });

From 01f8d78decbd6756925d15980a5be5a7a46d2e1a Mon Sep 17 00:00:00 2001
From: Alexander Kachkaev <alexander@kachkaev.ru>
Date: Sun, 30 Oct 2022 17:07:42 +0000
Subject: [PATCH 12/23] Update CHANGELOG.md

Co-authored-by: Simen Bekkhus <sbekkhus91@gmail.com>
---
 CHANGELOG.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 66f632af4cb3..c46276c9a822 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,7 @@
 
 ### Features
 
-- `[jest-runtime]` Support Wasm imports in ESM modules ([#13505](https://github.com/facebook/jest/pull/13505))
+- `[jest-runtime]` Support WebAssembly (Wasm) imports in ESM modules ([#13505](https://github.com/facebook/jest/pull/13505))
 
 ### Fixes
 

From 27d73b67eae02d27b94d9b6b62b8733ad9cf371e Mon Sep 17 00:00:00 2001
From: Alexander Kachkaev <alexander@kachkaev.ru>
Date: Sun, 30 Oct 2022 17:19:01 +0000
Subject: [PATCH 13/23] Mention Wasm in docs

---
 docs/ECMAScriptModules.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/docs/ECMAScriptModules.md b/docs/ECMAScriptModules.md
index e1ad627556a1..047eeabe576c 100644
--- a/docs/ECMAScriptModules.md
+++ b/docs/ECMAScriptModules.md
@@ -22,6 +22,8 @@ With the warnings out of the way, this is how you activate ESM support in your t
 
    If you use Yarn, you can use `yarn node --experimental-vm-modules $(yarn bin jest)`. This command will also work if you use [Yarn Plug'n'Play](https://yarnpkg.com/features/pnp).
 
+   If your codebase includes ESM imports from `*.wasm` files, you do _not_ need to pass `--experimental-wasm-modules` to `node`. Current implementation of WebAssembly imports in Jest relies on experimental VM modules, however, this may change in the future.
+
 1. Beyond that, we attempt to follow `node`'s logic for activating "ESM mode" (such as looking at `type` in `package.json` or `.mjs` files), see [their docs](https://nodejs.org/api/esm.html#esm_enabling) for details.
 1. If you want to treat other file extensions (such as `.jsx` or `.ts`) as ESM, please use the [`extensionsToTreatAsEsm` option](Configuration.md#extensionstotreatasesm-arraystring).
 

From 79e0f40d9397acb923595aa7c9070c24260f4274 Mon Sep 17 00:00:00 2001
From: Alexander Kachkaev <alexander@kachkaev.ru>
Date: Sun, 30 Oct 2022 18:23:17 +0000
Subject: [PATCH 14/23] Use Wasm file from mdn examples

---
 .../__snapshots__/nativeEsm.test.ts.snap      |   2 +-
 e2e/__tests__/nativeEsm.test.ts               |   2 +-
 e2e/native-esm/42.wasm                        | Bin 181 -> 0 bytes
 .../__tests__/native-esm-wasm.test.js         |  26 ++++++++++++++----
 e2e/native-esm/add.wasm                       | Bin 0 -> 41 bytes
 5 files changed, 23 insertions(+), 7 deletions(-)
 delete mode 100644 e2e/native-esm/42.wasm
 create mode 100644 e2e/native-esm/add.wasm

diff --git a/e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap b/e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap
index a9d283f5e7e1..950d7c45945c 100644
--- a/e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap
+++ b/e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap
@@ -8,7 +8,7 @@ Time:        <<REPLACED>>
 Ran all test suites matching /native-esm-deep-cjs-reexport.test.js/i."
 `;
 
-exports[`runs Wasm test with native ESM 1`] = `
+exports[`runs WebAssembly (Wasm) test with native ESM 1`] = `
 "Test Suites: 1 passed, 1 total
 Tests:       4 passed, 4 total
 Snapshots:   0 total
diff --git a/e2e/__tests__/nativeEsm.test.ts b/e2e/__tests__/nativeEsm.test.ts
index dd0078af63c7..a25d2dbd11c7 100644
--- a/e2e/__tests__/nativeEsm.test.ts
+++ b/e2e/__tests__/nativeEsm.test.ts
@@ -68,7 +68,7 @@ onNodeVersions('>=16.9.0', () => {
   });
 });
 
-test('runs Wasm test with native ESM', () => {
+test('runs WebAssembly (Wasm) test with native ESM', () => {
   const {exitCode, stderr, stdout} = runJest(DIR, ['native-esm-wasm.test.js'], {
     nodeOptions: '--experimental-vm-modules --no-warnings',
   });
diff --git a/e2e/native-esm/42.wasm b/e2e/native-esm/42.wasm
deleted file mode 100644
index 2dd107d7b789375eab071e611c0cae746f3b5c84..0000000000000000000000000000000000000000
GIT binary patch
literal 0
HcmV?d00001

literal 181
zcmWNLy$*sf6h?2$kD@L*xS2452~7(IVdNEj0t;M;2^7;p2yyV$ZSqa$oZ$m$1_A)Y
zBTpbdhZ67{0>{mn`U4K5UMU0}PL(nXYJi<jT&S*l_y!+6wsV8p&}}bOH_Hx*`<TrH
z2df%12HT`w9Zy@<Tm;KA#>41VmqO+!?_tW*G~tC^>@Tvnna`Oh89yxcRZ_oI+o3vf
Qma-xXBdld!idR;|f3hts^Z)<=

diff --git a/e2e/native-esm/__tests__/native-esm-wasm.test.js b/e2e/native-esm/__tests__/native-esm-wasm.test.js
index 17d4f4700823..2755c5e9805b 100644
--- a/e2e/native-esm/__tests__/native-esm-wasm.test.js
+++ b/e2e/native-esm/__tests__/native-esm-wasm.test.js
@@ -8,20 +8,36 @@
 // the point here is that it's the node core module
 // eslint-disable-next-line no-restricted-imports
 import {readFileSync} from 'fs';
-// The file was generated by wasm-pack
-import {getAnswer} from '../42.wasm';
+// file origin: https://github.com/mdn/webassembly-examples/blob/2f2163287f86fe29deb162335bccca7d5d95ca4f/understanding-text-format/add.wasm
+// source code: https://github.com/mdn/webassembly-examples/blob/2f2163287f86fe29deb162335bccca7d5d95ca4f/understanding-text-format/add.was
+import {add} from '../add.wasm';
 
-const wasmFileBuffer = readFileSync('42.wasm');
+const wasmFileBuffer = readFileSync('add.wasm');
 
 test('supports native wasm imports', () => {
-  expect(getAnswer()).toBe(42);
+  expect(add(1, 2)).toBe(3);
+
+  // because arguments are i32 (signed), fractional part is truncated
+  expect(add(0.99, 1.01)).toBe(1);
+
+  // because return value is i32 (signed), (2^31 - 1) + 1 overflows and becomes -2^31
+  expect(add(Math.pow(2, 31) - 1, 1)).toBe(-Math.pow(2, 31));
+
+  // invalid or missing arguments are treated as 0
+  expect(add('hello', 'world')).toBe(0);
+  expect(add()).toBe(0);
+  expect(add(null)).toBe(0);
+  expect(add({}, [])).toBe(0);
+
+  // redundant arguments are silently ignored
+  expect(add(1, 2, 3)).toBe(3);
 });
 
 test('supports imports from "data:application/wasm" URI with base64 encoding', async () => {
   const importedWasmModule = await import(
     `data:application/wasm;base64,${wasmFileBuffer.toString('base64')}`
   );
-  expect(importedWasmModule.getAnswer()).toBe(42);
+  expect(importedWasmModule.add(0, 42)).toBe(42);
 });
 
 test('imports from "data:text/wasm" URI without explicit encoding fail', async () => {
diff --git a/e2e/native-esm/add.wasm b/e2e/native-esm/add.wasm
new file mode 100644
index 0000000000000000000000000000000000000000..357f72da7a0db8add83699082fd51d46bf3352fb
GIT binary patch
literal 41
wcmZQbEY4+QU|?WmXG~zKuV<`hW@2PuXJ=$iOi5v2;NoOtXHZ~JV9eqM0DJxgJ^%m!

literal 0
HcmV?d00001


From 0d4945e45bf3297ffd190bf89c9aa41083025067 Mon Sep 17 00:00:00 2001
From: Alexander Kachkaev <alexander@kachkaev.ru>
Date: Sun, 30 Oct 2022 18:33:42 +0000
Subject: [PATCH 15/23] Implement `readFileBuffer`

---
 docs/CodeTransformation.md                 |  2 +-
 packages/babel-jest/src/__tests__/index.ts |  8 +++----
 packages/jest-repl/src/cli/repl.ts         |  2 +-
 packages/jest-runtime/src/index.ts         | 28 +++++++++++++++++++---
 4 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/docs/CodeTransformation.md b/docs/CodeTransformation.md
index 2d16208eb10f..3be3e0ac9a0e 100644
--- a/docs/CodeTransformation.md
+++ b/docs/CodeTransformation.md
@@ -40,7 +40,7 @@ interface TransformOptions<TransformerConfig = unknown> {
   supportsTopLevelAwait: boolean;
   instrument: boolean;
   /** Cached file system which is used by `jest-runtime` to improve performance. */
-  cacheFS: Map<string, string>;
+  cacheFS: Map<string, Buffer | string>;
   /** Jest configuration of currently running project. */
   config: ProjectConfig;
   /** Stringified version of the `config` - useful in cache busting. */
diff --git a/packages/babel-jest/src/__tests__/index.ts b/packages/babel-jest/src/__tests__/index.ts
index 9903c2b773b0..4808bd0e591a 100644
--- a/packages/babel-jest/src/__tests__/index.ts
+++ b/packages/babel-jest/src/__tests__/index.ts
@@ -52,7 +52,7 @@ test('Returns source string with inline maps when no transformOptions is passed'
     sourceString,
     'dummy_path.js',
     {
-      cacheFS: new Map<string, string>(),
+      cacheFS: new Map<string, Buffer | string>(),
       config: makeProjectConfig(),
       configString: JSON.stringify(makeProjectConfig()),
       instrument: false,
@@ -76,7 +76,7 @@ test('Returns source string with inline maps when no transformOptions is passed
     sourceString,
     'dummy_path.js',
     {
-      cacheFS: new Map<string, string>(),
+      cacheFS: new Map<string, Buffer | string>(),
       config: makeProjectConfig(),
       configString: JSON.stringify(makeProjectConfig()),
       instrument: false,
@@ -141,7 +141,7 @@ describe('caller option correctly merges from defaults and options', () => {
     ],
   ])('%j -> %j', (input, output) => {
     defaultBabelJestTransformer.process(sourceString, 'dummy_path.js', {
-      cacheFS: new Map<string, string>(),
+      cacheFS: new Map<string, Buffer | string>(),
       config: makeProjectConfig(),
       configString: JSON.stringify(makeProjectConfig()),
       instrument: false,
@@ -166,7 +166,7 @@ describe('caller option correctly merges from defaults and options', () => {
 test('can pass null to createTransformer', () => {
   const transformer = createTransformer();
   transformer.process(sourceString, 'dummy_path.js', {
-    cacheFS: new Map<string, string>(),
+    cacheFS: new Map<string, Buffer | string>(),
     config: makeProjectConfig(),
     configString: JSON.stringify(makeProjectConfig()),
     instrument: false,
diff --git a/packages/jest-repl/src/cli/repl.ts b/packages/jest-repl/src/cli/repl.ts
index 3a486c6bfbb7..aceb9f1fb180 100644
--- a/packages/jest-repl/src/cli/repl.ts
+++ b/packages/jest-repl/src/cli/repl.ts
@@ -33,7 +33,7 @@ const evalCommand: repl.REPLEval = (
         cmd,
         jestGlobalConfig.replname ?? 'jest.js',
         {
-          cacheFS: new Map<string, string>(),
+          cacheFS: new Map<string, Buffer | string>(),
           config: jestProjectConfig,
           configString: JSON.stringify(jestProjectConfig),
           instrument: false,
diff --git a/packages/jest-runtime/src/index.ts b/packages/jest-runtime/src/index.ts
index ed0d5f9e50c2..5941ec3076db 100644
--- a/packages/jest-runtime/src/index.ts
+++ b/packages/jest-runtime/src/index.ts
@@ -153,7 +153,7 @@ const supportsNodeColonModulePrefixInRequire = (() => {
 })();
 
 export default class Runtime {
-  private readonly _cacheFS: Map<string, string>;
+  private readonly _cacheFS: Map<string, Buffer | string>;
   private readonly _config: Config.ProjectConfig;
   private readonly _globalConfig?: Config.GlobalConfig;
   private readonly _coverageOptions: ShouldInstrumentOptions;
@@ -211,7 +211,7 @@ export default class Runtime {
     environment: JestEnvironment,
     resolver: Resolver,
     transformer: ScriptTransformer,
-    cacheFS: Map<string, string>,
+    cacheFS: Map<string, Buffer | string>,
     coverageOptions: ShouldInstrumentOptions,
     testPath: string,
     // TODO: make mandatory in Jest 30
@@ -446,7 +446,7 @@ export default class Runtime {
 
       if (modulePath.endsWith('.wasm')) {
         const wasm = this._importWasmModule(
-          fs.readFileSync(modulePath),
+          this.readFileBuffer(modulePath),
           modulePath,
           context,
         );
@@ -2376,6 +2376,23 @@ export default class Runtime {
     };
   }
 
+  private readFileBuffer(filename: string): Buffer {
+    let source = this._cacheFS.get(filename);
+
+    if (!source) {
+      source = fs.readFileSync(filename);
+
+      this._cacheFS.set(filename, source);
+    }
+
+    if (typeof source === 'string') {
+      // This may occur if readFileBuffer and readFile are called interchangeably for one file
+      throw new Error("Expected source to be a 'Buffer', but got 'string'");
+    }
+
+    return source;
+  }
+
   private readFile(filename: string): string {
     let source = this._cacheFS.get(filename);
 
@@ -2385,6 +2402,11 @@ export default class Runtime {
       this._cacheFS.set(filename, source);
     }
 
+    if (typeof source !== 'string') {
+      // This may occur if readFileBuffer and readFile are called interchangeably for one file
+      throw new Error("Expected source to be a 'string', but got 'Buffer'");
+    }
+
     return source;
   }
 

From 26db3fde3eb67fa82cd0ff8e7de19a74bdfff189 Mon Sep 17 00:00:00 2001
From: Alexander Kachkaev <alexander@kachkaev.ru>
Date: Sun, 30 Oct 2022 18:58:52 +0000
Subject: [PATCH 16/23] Call loadEsmModule instead of linkAndEvaluateModule in
 _importWasmModule

---
 packages/jest-runtime/src/index.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/jest-runtime/src/index.ts b/packages/jest-runtime/src/index.ts
index 5941ec3076db..ee3e548941b8 100644
--- a/packages/jest-runtime/src/index.ts
+++ b/packages/jest-runtime/src/index.ts
@@ -1680,7 +1680,7 @@ export default class Runtime {
     const moduleLookup: Record<string, VMModule> = {};
     for (const {module} of imports) {
       if (moduleLookup[module] === undefined) {
-        moduleLookup[module] = await this.linkAndEvaluateModule(
+        moduleLookup[module] = await this.loadEsmModule(
           await this.resolveModule(module, identifier, context),
         );
       }

From 1e6d75bc83a41a48c5f0de42bf823a380029b076 Mon Sep 17 00:00:00 2001
From: Alexander Kachkaev <alexander@kachkaev.ru>
Date: Mon, 31 Oct 2022 18:51:30 +0000
Subject: [PATCH 17/23] Update e2e/native-esm/__tests__/native-esm-wasm.test.js

---
 e2e/native-esm/__tests__/native-esm-wasm.test.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/e2e/native-esm/__tests__/native-esm-wasm.test.js b/e2e/native-esm/__tests__/native-esm-wasm.test.js
index 2755c5e9805b..8caa5cf40993 100644
--- a/e2e/native-esm/__tests__/native-esm-wasm.test.js
+++ b/e2e/native-esm/__tests__/native-esm-wasm.test.js
@@ -40,13 +40,13 @@ test('supports imports from "data:application/wasm" URI with base64 encoding', a
   expect(importedWasmModule.add(0, 42)).toBe(42);
 });
 
-test('imports from "data:text/wasm" URI without explicit encoding fail', async () => {
+test('imports from "data:application/wasm" URI without explicit encoding fail', async () => {
   await expect(() =>
     import(`data:application/wasm,${wasmFileBuffer.toString('base64')}`),
   ).rejects.toThrow('Missing data URI encoding');
 });
 
-test('imports from "data:text/wasm" URI with invalid encoding fail', async () => {
+test('imports from "data:application/wasm" URI with invalid encoding fail', async () => {
   await expect(() =>
     import('data:application/wasm;charset=utf-8,oops'),
   ).rejects.toThrow('Invalid data URI encoding: charset=utf-8');

From ad32edd04adecfb79f847fde95c1c12421307580 Mon Sep 17 00:00:00 2001
From: Alexander Kachkaev <alexander@kachkaev.ru>
Date: Tue, 1 Nov 2022 19:32:10 +0000
Subject: [PATCH 18/23] Add another test case for dynamic import

---
 e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap | 2 +-
 e2e/native-esm/__tests__/native-esm-wasm.test.js   | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap b/e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap
index 950d7c45945c..9d3fd2c87ec8 100644
--- a/e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap
+++ b/e2e/__tests__/__snapshots__/nativeEsm.test.ts.snap
@@ -10,7 +10,7 @@ Ran all test suites matching /native-esm-deep-cjs-reexport.test.js/i."
 
 exports[`runs WebAssembly (Wasm) test with native ESM 1`] = `
 "Test Suites: 1 passed, 1 total
-Tests:       4 passed, 4 total
+Tests:       5 passed, 5 total
 Snapshots:   0 total
 Time:        <<REPLACED>>
 Ran all test suites matching /native-esm-wasm.test.js/i."
diff --git a/e2e/native-esm/__tests__/native-esm-wasm.test.js b/e2e/native-esm/__tests__/native-esm-wasm.test.js
index 8caa5cf40993..853122085b4c 100644
--- a/e2e/native-esm/__tests__/native-esm-wasm.test.js
+++ b/e2e/native-esm/__tests__/native-esm-wasm.test.js
@@ -33,6 +33,11 @@ test('supports native wasm imports', () => {
   expect(add(1, 2, 3)).toBe(3);
 });
 
+test('supports dynamic wasm imports', async () => {
+  const {add: dynamicAdd} = await import('../add.wasm');
+  expect(dynamicAdd(1, 2)).toBe(3);
+});
+
 test('supports imports from "data:application/wasm" URI with base64 encoding', async () => {
   const importedWasmModule = await import(
     `data:application/wasm;base64,${wasmFileBuffer.toString('base64')}`

From 397bcd113fe4d8334611b6d5a415f6be367bc7fc Mon Sep 17 00:00:00 2001
From: Alexander Kachkaev <alexander@kachkaev.ru>
Date: Tue, 1 Nov 2022 19:34:21 +0000
Subject: [PATCH 19/23] Extract `isWasm` function

---
 packages/jest-runtime/src/index.ts | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/packages/jest-runtime/src/index.ts b/packages/jest-runtime/src/index.ts
index 0d9bf4a2ca62..bea182dd1a42 100644
--- a/packages/jest-runtime/src/index.ts
+++ b/packages/jest-runtime/src/index.ts
@@ -134,6 +134,8 @@ const getModuleNameMapper = (config: Config.ProjectConfig) => {
   return null;
 };
 
+const isWasm = (modulePath: string): boolean => modulePath.endsWith('.wasm');
+
 const unmockRegExpCache = new WeakMap();
 
 const EVAL_RESULT_VARIABLE = 'Object.<anonymous>';
@@ -397,11 +399,11 @@ export default class Runtime {
   }
 
   // unstable as it should be replaced by https://github.com/nodejs/modules/issues/393, and we don't want people to use it
-  unstable_shouldLoadAsEsm(path: string): boolean {
+  unstable_shouldLoadAsEsm(modulePath: string): boolean {
     return (
-      path.endsWith('.wasm') ||
+      isWasm(modulePath) ||
       Resolver.unstable_shouldLoadAsEsm(
-        path,
+        modulePath,
         this._config.extensionsToTreatAsEsm,
       )
     );
@@ -444,7 +446,7 @@ export default class Runtime {
         'Promise initialization should be sync - please report this bug to Jest!',
       );
 
-      if (modulePath.endsWith('.wasm')) {
+      if (isWasm(modulePath)) {
         const wasm = this._importWasmModule(
           this.readFileBuffer(modulePath),
           modulePath,

From 66a23125228767fb876a70347c31d7a63ac0b248 Mon Sep 17 00:00:00 2001
From: Simen Bekkhus <sbekkhus91@gmail.com>
Date: Sun, 6 Nov 2022 20:26:56 +0100
Subject: [PATCH 20/23] Revert "Implement `readFileBuffer`"

This reverts commit 0d4945e45bf3297ffd190bf89c9aa41083025067.
---
 docs/CodeTransformation.md                 |  2 +-
 packages/babel-jest/src/__tests__/index.ts |  8 +++----
 packages/jest-repl/src/cli/repl.ts         |  2 +-
 packages/jest-runtime/src/index.ts         | 28 +++-------------------
 4 files changed, 9 insertions(+), 31 deletions(-)

diff --git a/docs/CodeTransformation.md b/docs/CodeTransformation.md
index 3be3e0ac9a0e..2d16208eb10f 100644
--- a/docs/CodeTransformation.md
+++ b/docs/CodeTransformation.md
@@ -40,7 +40,7 @@ interface TransformOptions<TransformerConfig = unknown> {
   supportsTopLevelAwait: boolean;
   instrument: boolean;
   /** Cached file system which is used by `jest-runtime` to improve performance. */
-  cacheFS: Map<string, Buffer | string>;
+  cacheFS: Map<string, string>;
   /** Jest configuration of currently running project. */
   config: ProjectConfig;
   /** Stringified version of the `config` - useful in cache busting. */
diff --git a/packages/babel-jest/src/__tests__/index.ts b/packages/babel-jest/src/__tests__/index.ts
index 4808bd0e591a..9903c2b773b0 100644
--- a/packages/babel-jest/src/__tests__/index.ts
+++ b/packages/babel-jest/src/__tests__/index.ts
@@ -52,7 +52,7 @@ test('Returns source string with inline maps when no transformOptions is passed'
     sourceString,
     'dummy_path.js',
     {
-      cacheFS: new Map<string, Buffer | string>(),
+      cacheFS: new Map<string, string>(),
       config: makeProjectConfig(),
       configString: JSON.stringify(makeProjectConfig()),
       instrument: false,
@@ -76,7 +76,7 @@ test('Returns source string with inline maps when no transformOptions is passed
     sourceString,
     'dummy_path.js',
     {
-      cacheFS: new Map<string, Buffer | string>(),
+      cacheFS: new Map<string, string>(),
       config: makeProjectConfig(),
       configString: JSON.stringify(makeProjectConfig()),
       instrument: false,
@@ -141,7 +141,7 @@ describe('caller option correctly merges from defaults and options', () => {
     ],
   ])('%j -> %j', (input, output) => {
     defaultBabelJestTransformer.process(sourceString, 'dummy_path.js', {
-      cacheFS: new Map<string, Buffer | string>(),
+      cacheFS: new Map<string, string>(),
       config: makeProjectConfig(),
       configString: JSON.stringify(makeProjectConfig()),
       instrument: false,
@@ -166,7 +166,7 @@ describe('caller option correctly merges from defaults and options', () => {
 test('can pass null to createTransformer', () => {
   const transformer = createTransformer();
   transformer.process(sourceString, 'dummy_path.js', {
-    cacheFS: new Map<string, Buffer | string>(),
+    cacheFS: new Map<string, string>(),
     config: makeProjectConfig(),
     configString: JSON.stringify(makeProjectConfig()),
     instrument: false,
diff --git a/packages/jest-repl/src/cli/repl.ts b/packages/jest-repl/src/cli/repl.ts
index aceb9f1fb180..3a486c6bfbb7 100644
--- a/packages/jest-repl/src/cli/repl.ts
+++ b/packages/jest-repl/src/cli/repl.ts
@@ -33,7 +33,7 @@ const evalCommand: repl.REPLEval = (
         cmd,
         jestGlobalConfig.replname ?? 'jest.js',
         {
-          cacheFS: new Map<string, Buffer | string>(),
+          cacheFS: new Map<string, string>(),
           config: jestProjectConfig,
           configString: JSON.stringify(jestProjectConfig),
           instrument: false,
diff --git a/packages/jest-runtime/src/index.ts b/packages/jest-runtime/src/index.ts
index bea182dd1a42..95c49cc2a43a 100644
--- a/packages/jest-runtime/src/index.ts
+++ b/packages/jest-runtime/src/index.ts
@@ -155,7 +155,7 @@ const supportsNodeColonModulePrefixInRequire = (() => {
 })();
 
 export default class Runtime {
-  private readonly _cacheFS: Map<string, Buffer | string>;
+  private readonly _cacheFS: Map<string, string>;
   private readonly _config: Config.ProjectConfig;
   private readonly _globalConfig?: Config.GlobalConfig;
   private readonly _coverageOptions: ShouldInstrumentOptions;
@@ -213,7 +213,7 @@ export default class Runtime {
     environment: JestEnvironment,
     resolver: Resolver,
     transformer: ScriptTransformer,
-    cacheFS: Map<string, Buffer | string>,
+    cacheFS: Map<string, string>,
     coverageOptions: ShouldInstrumentOptions,
     testPath: string,
     // TODO: make mandatory in Jest 30
@@ -448,7 +448,7 @@ export default class Runtime {
 
       if (isWasm(modulePath)) {
         const wasm = this._importWasmModule(
-          this.readFileBuffer(modulePath),
+          fs.readFileSync(modulePath),
           modulePath,
           context,
         );
@@ -2378,23 +2378,6 @@ export default class Runtime {
     };
   }
 
-  private readFileBuffer(filename: string): Buffer {
-    let source = this._cacheFS.get(filename);
-
-    if (!source) {
-      source = fs.readFileSync(filename);
-
-      this._cacheFS.set(filename, source);
-    }
-
-    if (typeof source === 'string') {
-      // This may occur if readFileBuffer and readFile are called interchangeably for one file
-      throw new Error("Expected source to be a 'Buffer', but got 'string'");
-    }
-
-    return source;
-  }
-
   private readFile(filename: string): string {
     let source = this._cacheFS.get(filename);
 
@@ -2404,11 +2387,6 @@ export default class Runtime {
       this._cacheFS.set(filename, source);
     }
 
-    if (typeof source !== 'string') {
-      // This may occur if readFileBuffer and readFile are called interchangeably for one file
-      throw new Error("Expected source to be a 'string', but got 'Buffer'");
-    }
-
     return source;
   }
 

From 7188086eebaec5861109a147df4d5f71a15ba7c2 Mon Sep 17 00:00:00 2001
From: Simen Bekkhus <sbekkhus91@gmail.com>
Date: Sun, 6 Nov 2022 20:29:44 +0100
Subject: [PATCH 21/23] separate buffer cache

---
 packages/jest-runtime/src/index.ts | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/packages/jest-runtime/src/index.ts b/packages/jest-runtime/src/index.ts
index 95c49cc2a43a..c23b2a0bc64e 100644
--- a/packages/jest-runtime/src/index.ts
+++ b/packages/jest-runtime/src/index.ts
@@ -156,6 +156,7 @@ const supportsNodeColonModulePrefixInRequire = (() => {
 
 export default class Runtime {
   private readonly _cacheFS: Map<string, string>;
+  private readonly _cacheFSBuffer = new Map<string, Buffer>();
   private readonly _config: Config.ProjectConfig;
   private readonly _globalConfig?: Config.GlobalConfig;
   private readonly _coverageOptions: ShouldInstrumentOptions;
@@ -448,7 +449,7 @@ export default class Runtime {
 
       if (isWasm(modulePath)) {
         const wasm = this._importWasmModule(
-          fs.readFileSync(modulePath),
+          this.readFileBuffer(modulePath),
           modulePath,
           context,
         );
@@ -2378,11 +2379,24 @@ export default class Runtime {
     };
   }
 
+  private readFileBuffer(filename: string): Buffer {
+    let source = this._cacheFSBuffer.get(filename);
+
+    if (!source) {
+      source = fs.readFileSync(filename);
+
+      this._cacheFSBuffer.set(filename, source);
+    }
+
+    return source;
+  }
+
   private readFile(filename: string): string {
     let source = this._cacheFS.get(filename);
 
     if (!source) {
-      source = fs.readFileSync(filename, 'utf8');
+      const buffer = this.readFileBuffer(filename);
+      source = buffer.toString('utf8');
 
       this._cacheFS.set(filename, source);
     }

From 26e7022706d928d24faf84e38270b7a3d66e9399 Mon Sep 17 00:00:00 2001
From: Simen Bekkhus <sbekkhus91@gmail.com>
Date: Sun, 6 Nov 2022 20:33:19 +0100
Subject: [PATCH 22/23] tweak

---
 e2e/native-esm/__tests__/native-esm-wasm.test.js | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/e2e/native-esm/__tests__/native-esm-wasm.test.js b/e2e/native-esm/__tests__/native-esm-wasm.test.js
index 853122085b4c..a48d6628eeff 100644
--- a/e2e/native-esm/__tests__/native-esm-wasm.test.js
+++ b/e2e/native-esm/__tests__/native-esm-wasm.test.js
@@ -5,9 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-// the point here is that it's the node core module
-// eslint-disable-next-line no-restricted-imports
-import {readFileSync} from 'fs';
+import {readFileSync} from 'node:fs';
 // file origin: https://github.com/mdn/webassembly-examples/blob/2f2163287f86fe29deb162335bccca7d5d95ca4f/understanding-text-format/add.wasm
 // source code: https://github.com/mdn/webassembly-examples/blob/2f2163287f86fe29deb162335bccca7d5d95ca4f/understanding-text-format/add.was
 import {add} from '../add.wasm';

From 607fc0f53bb48d104fecc77e380a2bf33f89f235 Mon Sep 17 00:00:00 2001
From: Simen Bekkhus <sbekkhus91@gmail.com>
Date: Sun, 6 Nov 2022 20:37:24 +0100
Subject: [PATCH 23/23] clear new cache as well

---
 packages/jest-runtime/src/index.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/jest-runtime/src/index.ts b/packages/jest-runtime/src/index.ts
index c23b2a0bc64e..5dcf6d7ce6c8 100644
--- a/packages/jest-runtime/src/index.ts
+++ b/packages/jest-runtime/src/index.ts
@@ -1147,6 +1147,7 @@ export default class Runtime {
     this._cjsNamedExports.clear();
     this._moduleMockRegistry.clear();
     this._cacheFS.clear();
+    this._cacheFSBuffer.clear();
 
     if (
       this._coverageOptions.collectCoverage &&