add check for node runtime and import from node buffer for Blob (#225)

* add check for node runtime and import from node buffer for Blob

* move Blob import to global scope of package

* migrate Blob injection to polyfil

packages/crypto/polyfills.js

@@ -0,0 +1,19 @@
+// This field will be automatically injected into the ./dist/packages/<package-name>/index.js file
+// between the autogen:polyfills:start/end comments
+
+try {
+  if (isNode()) {
+    try {
+      //@ts-ignore
+      let { Blob } = import('node:buffer').then((module) => {
+        globalThis.Blob = module.Blob;
+      });
+    } catch (e) {
+      log(
+        'Warn: could not resolve Blob from node api set, perhaps polyfil a Blob implementation of your choice'
+      );
+    }
+  }
+} catch (e) {
+  // swallow
+}

packages/crypto/src/lib/crypto.spec.ts

@@ -64,11 +64,23 @@ describe('encryptWithSymmetricKey', () => {
   let symmetricKey: CryptoKey;
 
   beforeAll(async () => {
+      try {
+        //@ts-ignore
+        import('node:buffer').then((module) => {
+          //@ts-ignore
+          globalThis.Blob = module.Blob;
+        });
+      } catch (e) {
+        console.log(
+          'Warn: could not resolve Blob from node api set, perhaps polyfil a Blob implementation of your choice'
+        );
+      }
     symmetricKey = await generateSymmetricKey();
   });
 
-  testData.forEach((data, index) => {
+  testData.forEach(async (data, index) => {
     it(`should encrypt data (test case ${index + 1})`, async () => {
+      const { Blob } = await import("node:buffer");
       const encryptedBlob = await encryptWithSymmetricKey(symmetricKey, data);
 
       expect(encryptedBlob).toBeDefined();

packages/crypto/src/lib/crypto.ts

@@ -11,7 +11,7 @@ import {
 
 import * as wasmECDSA from '@lit-protocol/ecdsa-sdk';
 
-import { isBrowser, log, throwError } from '@lit-protocol/misc';
+import { isBrowser, isNode, log, throwError } from '@lit-protocol/misc';
 
 import {
   uint8arrayFromString,
@@ -60,6 +60,8 @@ if (!globalThis.wasmECDSA) {
     }
   });
 }
+
+
 /** ---------- Exports ---------- */
 
 /**
@@ -101,7 +103,7 @@ export const encryptWithSymmetricKey = async (
     symmKey,
     data
   );
-
+  
   const encryptedZipBlob = new Blob([iv, new Uint8Array(encryptedZipData)], {
     type: 'application/octet-stream',
   });