2 files changed, 181 insertions, 19 deletions

diff --git a/packages/server/src/helpers/iso/isoCrypto/getWebCrypto.test.ts b/packages/server/src/helpers/iso/isoCrypto/getWebCrypto.test.ts
new file mode 100644
index 0000000..26025b8
--- /dev/null
+++ b/packages/server/src/helpers/iso/isoCrypto/getWebCrypto.test.ts
@@ -0,0 +1,149 @@
+import { assertEquals, assertRejects } from 'https://deno.land/std@0.198.0/assert/mod.ts';
+import { returnsNext, stub } from 'https://deno.land/std@0.198.0/testing/mock.ts';
+
+import { _getWebCryptoInternals, getWebCrypto, MissingWebCrypto } from './getWebCrypto.ts';
+
+Deno.test('should return globalThis.crypto when present', async () => {
+  // Clear whatever version of crypto might have been set
+  _getWebCryptoInternals.setCachedCrypto(undefined);
+
+  // Pretend globalThis.crypto exists
+  const newGlobalThisCrypto = {};
+  const mockGlobalThisCrypto = stub(
+    _getWebCryptoInternals,
+    'stubThisGlobalThisCrypto',
+    // @ts-ignore: globalThis.crypto
+    returnsNext([newGlobalThisCrypto]),
+  );
+
+  const returnedCrypto = await getWebCrypto();
+
+  assertEquals(returnedCrypto, newGlobalThisCrypto);
+
+  mockGlobalThisCrypto.restore();
+});
+
+Deno.test('should return node:crypto.webcrypto when globalThis.crypto is missing', async () => {
+  // Clear whatever version of crypto might have been set
+  _getWebCryptoInternals.setCachedCrypto(undefined);
+
+  // Pretend globalThis.crypto doesn't exist
+  const mockGlobalThisCrypto = stub(
+    _getWebCryptoInternals,
+    'stubThisGlobalThisCrypto',
+    // @ts-ignore: globalThis.crypto
+    returnsNext([undefined]),
+  );
+
+  // Mock out just enough of the 'node:crypto' module
+  const fakeNodeCrypto = { webcrypto: {} };
+  const mockImportNodeCrypto = stub(
+    _getWebCryptoInternals,
+    'stubThisImportNodeCrypto',
+    // @ts-ignore: node:crypto
+    returnsNext([fakeNodeCrypto]),
+  );
+
+  const returnedCrypto = await getWebCrypto();
+
+  assertEquals(returnedCrypto, fakeNodeCrypto.webcrypto);
+
+  mockGlobalThisCrypto.restore();
+  mockImportNodeCrypto.restore();
+});
+
+Deno.test(
+  'should return globalThis.crypto when present, while node:crypto.webcrypto is present',
+  async () => {
+    // Clear whatever version of crypto might have been set
+    _getWebCryptoInternals.setCachedCrypto(undefined);
+
+    // Pretend globalThis.crypto exists
+    const fakeGlobalThisCrypto = {};
+    const mockGlobalThisCrypto = stub(
+      _getWebCryptoInternals,
+      'stubThisGlobalThisCrypto',
+      // @ts-ignore: globalThis.crypto
+      returnsNext([fakeGlobalThisCrypto]),
+    );
+
+    // Mock out just enough of the 'node:crypto' module, but like we're in Node v14
+    const fakeNodeCrypto = { webcrypto: {} };
+    const mockImportNodeCrypto = stub(
+      _getWebCryptoInternals,
+      'stubThisImportNodeCrypto',
+      // @ts-ignore: node:crypto
+      returnsNext([fakeNodeCrypto]),
+    );
+
+    const returnedCrypto = await getWebCrypto();
+
+    assertEquals(returnedCrypto, fakeGlobalThisCrypto);
+
+    mockGlobalThisCrypto.restore();
+    mockImportNodeCrypto.restore();
+  },
+);
+
+Deno.test(
+  'should return globalThis.crypto when present, while node:crypto is present but missing webcrypto',
+  async () => {
+    // Clear whatever version of crypto might have been set
+    _getWebCryptoInternals.setCachedCrypto(undefined);
+
+    // Pretend globalThis.crypto exists
+    const fakeGlobalThisCrypto = {};
+    const mockGlobalThisCrypto = stub(
+      _getWebCryptoInternals,
+      'stubThisGlobalThisCrypto',
+      // @ts-ignore: globalThis.crypto
+      returnsNext([fakeGlobalThisCrypto]),
+    );
+
+    // Mock out just enough of the 'node:crypto' module, but like we're in Node v14
+    const fakeNodeCrypto = { webcrypto: undefined };
+    const mockImportNodeCrypto = stub(
+      _getWebCryptoInternals,
+      'stubThisImportNodeCrypto',
+      // @ts-ignore: node:crypto
+      returnsNext([fakeNodeCrypto]),
+    );
+
+    const returnedCrypto = await getWebCrypto();
+
+    assertEquals(returnedCrypto, fakeGlobalThisCrypto);
+
+    mockGlobalThisCrypto.restore();
+    mockImportNodeCrypto.restore();
+  },
+);
+
+Deno.test('should raise MissingWebCrypto error when nothing is available', async () => {
+  // Clear whatever version of crypto might have been set
+  _getWebCryptoInternals.setCachedCrypto(undefined);
+
+  // Pretend globalThis.crypto doesn't exist
+  const mockGlobalThisCrypto = stub(
+    _getWebCryptoInternals,
+    'stubThisGlobalThisCrypto',
+    // @ts-ignore: globalThis.crypto
+    returnsNext([undefined]),
+  );
+
+  // Pretend node:crypto doesn't exist
+  const mockImportNodeCrypto = stub(
+    _getWebCryptoInternals,
+    'stubThisImportNodeCrypto',
+    // @ts-ignore: node:crypto
+    returnsNext([undefined]),
+  );
+
+  await assertRejects(
+    () => getWebCrypto(),
+    MissingWebCrypto,
+    'Crypto API could not be located',
+  );
+
+  mockGlobalThisCrypto.restore();
+  mockImportNodeCrypto.restore();
+});
diff --git a/packages/server/src/helpers/iso/isoCrypto/getWebCrypto.ts b/packages/server/src/helpers/iso/isoCrypto/getWebCrypto.ts
index a5e580e..fe86219 100644
--- a/packages/server/src/helpers/iso/isoCrypto/getWebCrypto.ts
+++ b/packages/server/src/helpers/iso/isoCrypto/getWebCrypto.ts
@@ -11,37 +11,50 @@ export async function getWebCrypto(): Promise<Crypto> {
     return webCrypto;
   }
 
+  /**
+   * Naively attempt to access Crypto as a global object, which popular alternative run-times
+   * support.
+   */
+  const _crypto = _getWebCryptoInternals.stubThisGlobalThisCrypto();
+
+  if (_crypto) {
+    webCrypto = _crypto;
+    return webCrypto;
+  }
+
   try {
     /**
-     * Naively attempt a Node import...
-     */
-    // @ts-ignore: We'll handle any errors...
-    // dnt-shim-ignore
-    const _crypto = await import('node:crypto');
-    webCrypto = _crypto.webcrypto as Crypto;
-  } catch (_err) {
-    /**
-     * Naively attempt to access Crypto as a global object, which popular alternative run-times
-     * support.
+     * `globalThis.crypto` isn't available, so attempt a Node import...
      */
-    // @ts-ignore: ...right here.
-    const _crypto: Crypto = globalThis.crypto;
+    const _crypto = await _getWebCryptoInternals.stubThisImportNodeCrypto();
 
-    if (!_crypto) {
-      // We tried to access it both in Node and globally, so bail out
-      throw new MissingWebCrypto();
+    if (_crypto.webcrypto) {
+      webCrypto = _crypto.webcrypto as Crypto;
+      return webCrypto;
     }
-
-    webCrypto = _crypto;
+  } catch (_err) {
+    // pass
   }
 
-  return webCrypto;
+  // We tried to access it both in Node and globally, so bail out
+  throw new MissingWebCrypto();
 }
 
-class MissingWebCrypto extends Error {
+export class MissingWebCrypto extends Error {
   constructor() {
     const message = 'An instance of the Crypto API could not be located';
     super(message);
     this.name = 'MissingWebCrypto';
   }
 }
+
+// Make it possible to stub return values during testing
+export const _getWebCryptoInternals = {
+  // dnt-shim-ignore
+  stubThisImportNodeCrypto: () => import('node:crypto'),
+  stubThisGlobalThisCrypto: () => globalThis.crypto,
+  // Make it possible to reset the `webCrypto` at the top of the file
+  setCachedCrypto: (newCrypto: Crypto | undefined) => {
+    webCrypto = newCrypto;
+  },
+};