diff --git a/docs/long-term-plans/jwt-derived-encryption.md b/docs/long-term-plans/jwt-derived-encryption.md
index ec460a70e6..b6bdeb6fc4 100644
--- a/docs/long-term-plans/jwt-derived-encryption.md
+++ b/docs/long-term-plans/jwt-derived-encryption.md
@@ -81,7 +81,7 @@ export interface SuperSyncPrivateCfg extends SyncProviderPrivateCfgBase {
 
 ### Phase 2: Encryption Function (0.5 day)
 
-**File:** `src/app/op-log/encryption/encryption.ts`
+**File:** `packages/sync-core/src/encryption.ts`
 
 **Add:**
 
@@ -196,7 +196,7 @@ async getEncryptKey(): Promise<string | undefined> {
 | File                                                         | Changes                                            |
 | ------------------------------------------------------------ | -------------------------------------------------- |
 | `packages/sync-providers/src/super-sync/super-sync.model.ts` | Add `isAutoEncryptionEnabled`, `autoEncryptionKey` |
-| `src/app/op-log/encryption/encryption.ts`                    | Add `deriveKeyFromHighEntropy()`                   |
+| `packages/sync-core/src/encryption.ts`                       | Add `deriveKeyFromHighEntropy()`                   |
 | `src/app/op-log/sync-providers/super-sync/super-sync.ts`     | Modify `getEncryptKey()`                           |
 | `src/app/op-log/sync/operation-encryption.service.ts`        | Support pre-derived keys                           |
 | `src/app/features/config/form-cfgs/sync-form.const.ts`       | Add UI toggle                                      |
diff --git a/package-lock.json b/package-lock.json
index 000635a3ce..1d3498e4d6 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -29733,6 +29733,10 @@
     "packages/sync-core": {
       "name": "@sp/sync-core",
       "version": "1.0.0",
+      "dependencies": {
+        "@noble/ciphers": "^2.2.0",
+        "hash-wasm": "^4.12.0"
+      },
       "devDependencies": {
         "tsup": "^8.0.0",
         "typescript": "^5.0.0",
diff --git a/packages/sync-core/package.json b/packages/sync-core/package.json
index 88c0aa5a7a..422d6156a1 100644
--- a/packages/sync-core/package.json
+++ b/packages/sync-core/package.json
@@ -24,6 +24,10 @@
     "test": "vitest run",
     "test:watch": "vitest"
   },
+  "dependencies": {
+    "@noble/ciphers": "^2.2.0",
+    "hash-wasm": "^4.12.0"
+  },
   "devDependencies": {
     "tsup": "^8.0.0",
     "typescript": "^5.0.0",
diff --git a/src/app/op-log/encryption/encryption.ts b/packages/sync-core/src/encryption.ts
similarity index 91%
rename from src/app/op-log/encryption/encryption.ts
rename to packages/sync-core/src/encryption.ts
index 17911d1cab..9782623fb6 100644
--- a/src/app/op-log/encryption/encryption.ts
+++ b/packages/sync-core/src/encryption.ts
@@ -1,7 +1,6 @@
 import { argon2id } from 'hash-wasm';
 import { gcm } from '@noble/ciphers/aes.js';
-import { WebCryptoNotAvailableError } from '../core/errors/sync-errors';
-import { Log } from '../../core/log';
+import { WebCryptoNotAvailableError } from './web-crypto-error';
 
 const ALGORITHM = 'AES-GCM' as const;
 const SALT_LENGTH = 16;
@@ -16,6 +15,54 @@ const DEFAULT_ARGON2_PARAMS = {
 
 let _argon2Params = { ...DEFAULT_ARGON2_PARAMS };
 
+interface EncryptionProcessGlobal {
+  process?: {
+    env?: {
+      NODE_ENV?: string;
+    };
+  };
+}
+
+interface EncryptionGlobals extends EncryptionProcessGlobal {
+  crypto?: Crypto;
+  atob?: (input: string) => string;
+  btoa?: (input: string) => string;
+}
+
+const globals = (): EncryptionGlobals => globalThis as unknown as EncryptionGlobals;
+
+const getRequiredCrypto = (): Crypto => {
+  const cryptoApi = globals().crypto;
+  if (cryptoApi === undefined) {
+    throw new WebCryptoNotAvailableError('Crypto API is not available');
+  }
+  return cryptoApi;
+};
+
+const getRequiredSubtle = (): SubtleCrypto => {
+  const subtle = getRequiredCrypto().subtle;
+  if (subtle === undefined) {
+    throw new WebCryptoNotAvailableError();
+  }
+  return subtle;
+};
+
+const getRequiredAtob = (): ((input: string) => string) => {
+  const atob = globals().atob;
+  if (atob === undefined) {
+    throw new Error('atob is not available in this runtime');
+  }
+  return atob;
+};
+
+const getRequiredBtoa = (): ((input: string) => string) => {
+  const btoa = globals().btoa;
+  if (btoa === undefined) {
+    throw new Error('btoa is not available in this runtime');
+  }
+  return btoa;
+};
+
 /**
  * Returns the current Argon2 parameters.
  * Tests can override these via `setArgon2ParamsForTesting()`.
@@ -29,6 +76,9 @@ export const getArgon2Params = (): typeof DEFAULT_ARGON2_PARAMS => _argon2Params
 export const setArgon2ParamsForTesting = (
   params?: Partial<typeof DEFAULT_ARGON2_PARAMS>,
 ): void => {
+  if (globals().process?.env?.NODE_ENV === 'production') {
+    throw new Error('setArgon2ParamsForTesting must not be called in production');
+  }
   _argon2Params = params
     ? { ...DEFAULT_ARGON2_PARAMS, ...params }
     : { ...DEFAULT_ARGON2_PARAMS };
@@ -49,11 +99,7 @@ export const setArgon2ParamsForTesting = (
  * Returns false in insecure contexts (http://, some custom schemes like Android Capacitor).
  */
 export const isCryptoSubtleAvailable = (): boolean => {
-  return (
-    typeof window !== 'undefined' &&
-    typeof window.crypto !== 'undefined' &&
-    typeof window.crypto.subtle !== 'undefined'
-  );
+  return globals().crypto?.subtle !== undefined;
 };
 
 // ============================================================================
@@ -74,7 +120,7 @@ export type DerivedKeyInfo =
  * Strategy interface for cryptographic operations.
  * Implemented by WebCrypto and @noble/ciphers backends.
  */
-interface CryptoStrategy {
+export interface CryptoStrategy {
   encrypt(key: DerivedKeyInfo, iv: Uint8Array, data: Uint8Array): Promise<Uint8Array>;
   decrypt(key: DerivedKeyInfo, iv: Uint8Array, data: Uint8Array): Promise<Uint8Array>;
   deriveKey(password: string, salt: Uint8Array): Promise<DerivedKeyInfo>;
@@ -109,7 +155,7 @@ const webCryptoStrategy: CryptoStrategy = {
     if (keyInfo.type !== 'webcrypto') {
       throw new Error('WebCrypto strategy requires webcrypto key type');
     }
-    const encrypted = await window.crypto.subtle.encrypt(
+    const encrypted = await getRequiredSubtle().encrypt(
       { name: ALGORITHM, iv: iv as Uint8Array<ArrayBuffer> },
       keyInfo.key,
       data as Uint8Array<ArrayBuffer>,
@@ -121,7 +167,7 @@ const webCryptoStrategy: CryptoStrategy = {
     if (keyInfo.type !== 'webcrypto') {
       throw new Error('WebCrypto strategy requires webcrypto key type');
     }
-    const decrypted = await window.crypto.subtle.decrypt(
+    const decrypted = await getRequiredSubtle().decrypt(
       { name: ALGORITHM, iv: iv as Uint8Array<ArrayBuffer> },
       keyInfo.key,
       data as Uint8Array<ArrayBuffer>,
@@ -131,7 +177,7 @@ const webCryptoStrategy: CryptoStrategy = {
 
   deriveKey: async (password, salt) => {
     const derivedBytes = await deriveKeyBytesArgon(password, salt);
-    const key = await window.crypto.subtle.importKey(
+    const key = await getRequiredSubtle().importKey(
       'raw',
       derivedBytes.buffer as ArrayBuffer,
       { name: ALGORITHM },
@@ -250,7 +296,7 @@ export const getSessionKeyCacheStats = (): {
 // ============================================================================
 
 export const base642ab = (base64: string): ArrayBuffer => {
-  const binary_string = window.atob(base64);
+  const binary_string = getRequiredAtob()(base64);
   const len = binary_string.length;
   const bytes = new Uint8Array(len);
   for (let i = 0; i < len; i++) {
@@ -263,7 +309,7 @@ export const ab2base64 = (buffer: ArrayBuffer): string => {
   const binary = Array.prototype.map
     .call(new Uint8Array(buffer), (byte: number) => String.fromCharCode(byte))
     .join('');
-  return window.btoa(binary);
+  return getRequiredBtoa()(binary);
 };
 
 /**
@@ -271,7 +317,7 @@ export const ab2base64 = (buffer: ArrayBuffer): string => {
  * Uses crypto.getRandomValues which is available even without crypto.subtle.
  */
 const getRandomBytes = (length: number): Uint8Array<ArrayBuffer> => {
-  return window.crypto.getRandomValues(new Uint8Array(length));
+  return getRequiredCrypto().getRandomValues(new Uint8Array(length));
 };
 
 // Minimum sizes for format detection
@@ -313,25 +359,22 @@ const _generateKey = async (password: string): Promise<CryptoKey> => {
     iterations: 1000,
     hash: 'SHA-256',
   };
-  const key = await window.crypto.subtle.importKey(
+  const key = await getRequiredSubtle().importKey(
     'raw',
     passwordBuffer,
     { name: 'PBKDF2' },
     false,
     ['deriveBits', 'deriveKey'],
   );
-  return window.crypto.subtle.deriveKey(
-    ops,
-    key,
-    { name: ALGORITHM, length: 256 },
-    true,
-    ['encrypt', 'decrypt'],
-  );
+  return getRequiredSubtle().deriveKey(ops, key, { name: ALGORITHM, length: 256 }, true, [
+    'encrypt',
+    'decrypt',
+  ]);
 };
 
 export const generateKey = async (password: string): Promise<string> => {
   const cryptoKey = await _generateKey(password);
-  const exportKey = await window.crypto.subtle.exportKey('raw', cryptoKey);
+  const exportKey = await getRequiredSubtle().exportKey('raw', cryptoKey);
   return ab2base64(exportKey);
 };
 
@@ -351,18 +394,12 @@ async function decryptLegacy(data: string, password: string): Promise<string> {
   const iv = new Uint8Array(dataBuffer, 0, IV_LENGTH);
   const encryptedData = new Uint8Array(dataBuffer, IV_LENGTH);
   const key = await _generateKey(password);
-  const decryptedContent = await window.crypto.subtle.decrypt(
+  const decryptedContent = await getRequiredSubtle().decrypt(
     { name: ALGORITHM, iv: iv },
     key,
     encryptedData,
   );
 
-  // Only warn AFTER successful decryption, to avoid false positives when
-  // Argon2id decryption fails for other reasons (wrong password, corrupted data)
-  Log.warn(
-    '[DEPRECATION] Legacy PBKDF2 encryption detected. Consider re-syncing to migrate to Argon2id.',
-  );
-
   const dec = new TextDecoder();
   return dec.decode(decryptedContent);
 }
@@ -410,8 +447,6 @@ export const decrypt = async (data: string, password: string): Promise<string> =
     // Fallback to legacy decryption (pre-Argon2 format)
     // NOTE: Legacy PBKDF2 decryption requires WebCrypto. If WebCrypto is unavailable
     // and this is legacy data, the user will get a clear error.
-    // The deprecation warning is only emitted if legacy decryption SUCCEEDS,
-    // avoiding false positives when Argon2id fails for other reasons (wrong password).
     return await decryptLegacy(data, password);
   }
 };
@@ -428,6 +463,8 @@ export interface DecryptResult {
   migratedCiphertext?: string;
   /** True if the data was encrypted with legacy PBKDF2 */
   wasLegacy: boolean;
+  /** True if the data used the legacy PBKDF2 KDF */
+  wasLegacyKdf?: boolean;
 }
 
 /**
@@ -452,7 +489,7 @@ export const decryptWithMigration = async (
     // Fallback to legacy PBKDF2 format - decrypt and prepare migration
     const plaintext = await decryptLegacy(data, password);
     const migratedCiphertext = await encrypt(plaintext, password);
-    return { plaintext, migratedCiphertext, wasLegacy: true };
+    return { plaintext, migratedCiphertext, wasLegacy: true, wasLegacyKdf: true };
   }
 };
 
diff --git a/packages/sync-core/src/index.ts b/packages/sync-core/src/index.ts
index e0bcc71357..c06edadbb5 100644
--- a/packages/sync-core/src/index.ts
+++ b/packages/sync-core/src/index.ts
@@ -55,8 +55,31 @@ export {
 } from './compression';
 export type { GzipCompressionLogMessages, GzipCompressionOptions } from './compression';
 
+// Encryption primitives — Argon2id KDF + AES-GCM, Web Crypto with @noble fallback.
+export {
+  encrypt,
+  decrypt,
+  encryptBatch,
+  decryptBatch,
+  generateKey,
+  deriveKeyFromPassword,
+  encryptWithDerivedKey,
+  decryptWithDerivedKey,
+  decryptWithMigration,
+  getCryptoStrategy,
+  isCryptoSubtleAvailable,
+  clearSessionKeyCache,
+  getSessionKeyCacheStats,
+  getArgon2Params,
+  setArgon2ParamsForTesting,
+  base642ab,
+  ab2base64,
+} from './encryption';
+export type { CryptoStrategy, DerivedKeyInfo, DecryptResult } from './encryption';
+
 // Generic error helpers.
 export { extractErrorMessage } from './error.util';
+export { WebCryptoNotAvailableError } from './web-crypto-error';
 
 // Full-state operation classification helper. Hosts supply their own op strings.
 export {
diff --git a/packages/sync-core/src/web-crypto-error.ts b/packages/sync-core/src/web-crypto-error.ts
new file mode 100644
index 0000000000..5e729c40d1
--- /dev/null
+++ b/packages/sync-core/src/web-crypto-error.ts
@@ -0,0 +1,7 @@
+export class WebCryptoNotAvailableError extends Error {
+  override name = 'WebCryptoNotAvailableError';
+
+  constructor(message = 'Web Crypto API (crypto.subtle) is not available') {
+    super(message);
+  }
+}
diff --git a/packages/sync-core/tests/encryption.spec.ts b/packages/sync-core/tests/encryption.spec.ts
new file mode 100644
index 0000000000..201644eb40
--- /dev/null
+++ b/packages/sync-core/tests/encryption.spec.ts
@@ -0,0 +1,36 @@
+import { describe, expect, it } from 'vitest';
+import {
+  WebCryptoNotAvailableError,
+  decrypt,
+  encrypt,
+  isCryptoSubtleAvailable,
+  setArgon2ParamsForTesting,
+} from '../src';
+
+describe('encryption primitives', () => {
+  it('exposes Web Crypto availability check', () => {
+    expect(typeof isCryptoSubtleAvailable()).toBe('boolean');
+  });
+
+  it('round-trips a string through encrypt/decrypt with the same password', async () => {
+    if (!isCryptoSubtleAvailable()) {
+      return;
+    }
+
+    setArgon2ParamsForTesting({ parallelism: 1, memorySize: 8, iterations: 1 });
+    try {
+      const plaintext = 'hello sync world';
+      const ciphertext = await encrypt(plaintext, 'correct horse battery staple');
+      expect(ciphertext).not.toBe(plaintext);
+      await expect(decrypt(ciphertext, 'correct horse battery staple')).resolves.toBe(
+        plaintext,
+      );
+    } finally {
+      setArgon2ParamsForTesting();
+    }
+  });
+
+  it('exports WebCryptoNotAvailableError', () => {
+    expect(new WebCryptoNotAvailableError()).toBeInstanceOf(Error);
+  });
+});
diff --git a/packages/sync-core/tsconfig.json b/packages/sync-core/tsconfig.json
index cabc0b830d..5eeeb1689c 100644
--- a/packages/sync-core/tsconfig.json
+++ b/packages/sync-core/tsconfig.json
@@ -3,7 +3,7 @@
     "target": "ES2022",
     "module": "preserve",
     "moduleResolution": "bundler",
-    "lib": ["ES2022"],
+    "lib": ["ES2022", "DOM"],
     "declaration": true,
     "declarationMap": true,
     "sourceMap": true,
diff --git a/src/app/imex/sync/encryption-password-change.service.ts b/src/app/imex/sync/encryption-password-change.service.ts
index cda4fd78dd..041f6fd598 100644
--- a/src/app/imex/sync/encryption-password-change.service.ts
+++ b/src/app/imex/sync/encryption-password-change.service.ts
@@ -4,7 +4,7 @@ import { isOperationSyncCapable } from '../../op-log/sync/operation-sync.util';
 import { SyncProviderId } from '../../op-log/sync-providers/provider.const';
 import type { SuperSyncPrivateCfg } from '@sp/sync-providers/super-sync';
 import { SyncLog } from '../../core/log';
-import { clearSessionKeyCache } from '../../op-log/encryption/encryption';
+import { clearSessionKeyCache } from '@sp/sync-core';
 import { CleanSlateService } from '../../op-log/clean-slate/clean-slate.service';
 import { OperationLogUploadService } from '../../op-log/sync/operation-log-upload.service';
 import { SyncWrapperService } from './sync-wrapper.service';
diff --git a/src/app/imex/sync/file-based-encryption.service.ts b/src/app/imex/sync/file-based-encryption.service.ts
index ff83934f7a..d68c891261 100644
--- a/src/app/imex/sync/file-based-encryption.service.ts
+++ b/src/app/imex/sync/file-based-encryption.service.ts
@@ -14,7 +14,7 @@ import { FileBasedSyncAdapterService } from '../../op-log/sync-providers/file-ba
 import { CURRENT_SCHEMA_VERSION } from '../../op-log/persistence/schema-migration.service';
 import { uuidv7 } from '../../util/uuid-v7';
 import { GlobalConfigService } from '../../features/config/global-config.service';
-import { clearSessionKeyCache } from '../../op-log/encryption/encryption';
+import { clearSessionKeyCache } from '@sp/sync-core';
 
 const LOG_PREFIX = 'FileBasedEncryptionService';
 
diff --git a/src/app/imex/sync/snapshot-upload.service.ts b/src/app/imex/sync/snapshot-upload.service.ts
index 1f427eba79..9b5d4406ed 100644
--- a/src/app/imex/sync/snapshot-upload.service.ts
+++ b/src/app/imex/sync/snapshot-upload.service.ts
@@ -21,7 +21,7 @@ import {
 } from '../../op-log/sync-providers/provider.interface';
 import { VectorClock } from '../../core/util/vector-clock';
 import { OperationEncryptionService } from '../../op-log/sync/operation-encryption.service';
-import { isCryptoSubtleAvailable } from '../../op-log/encryption/encryption';
+import { isCryptoSubtleAvailable } from '@sp/sync-core';
 import { WebCryptoNotAvailableError } from '../../op-log/core/errors/sync-errors';
 
 /**
diff --git a/src/app/imex/sync/sync-config.service.ts b/src/app/imex/sync/sync-config.service.ts
index cbd2e46109..0b17b80942 100644
--- a/src/app/imex/sync/sync-config.service.ts
+++ b/src/app/imex/sync/sync-config.service.ts
@@ -11,7 +11,7 @@ import {
 } from '../../op-log/sync-exports';
 import { DEFAULT_GLOBAL_CONFIG } from '../../features/config/default-global-config.const';
 import { SyncLog } from '../../core/log';
-import { clearSessionKeyCache } from '../../op-log/encryption/encryption';
+import { clearSessionKeyCache } from '@sp/sync-core';
 import type { SuperSyncPrivateCfg } from '@sp/sync-providers/super-sync';
 import { SyncWrapperService } from './sync-wrapper.service';
 
diff --git a/src/app/op-log/core/errors/sync-errors.ts b/src/app/op-log/core/errors/sync-errors.ts
index 802e6fc722..453cc529d1 100644
--- a/src/app/op-log/core/errors/sync-errors.ts
+++ b/src/app/op-log/core/errors/sync-errors.ts
@@ -406,9 +406,7 @@ export class BackupImportFailedError extends AdditionalLogErrorBase {
   override name = 'BackupImportFailedError';
 }
 
-export class WebCryptoNotAvailableError extends Error {
-  override name = 'WebCryptoNotAvailableError';
-}
+export { WebCryptoNotAvailableError } from '@sp/sync-core';
 
 /**
  * Thrown when IndexedDB storage quota is exceeded during operation log write.
diff --git a/src/app/op-log/encryption/encrypt-and-compress-handler.service.ts b/src/app/op-log/encryption/encrypt-and-compress-handler.service.ts
index 37810c9714..72a70cf83a 100644
--- a/src/app/op-log/encryption/encrypt-and-compress-handler.service.ts
+++ b/src/app/op-log/encryption/encrypt-and-compress-handler.service.ts
@@ -2,9 +2,8 @@ import {
   extractSyncFileStateFromPrefix,
   getSyncFilePrefix,
 } from '../util/sync-file-prefix';
-import type { SyncLogger } from '@sp/sync-core';
+import { decryptBatch, encryptBatch, type SyncLogger } from '@sp/sync-core';
 import { OP_LOG_SYNC_LOGGER } from '../core/sync-logger.adapter';
-import { decryptBatch, encryptBatch } from './encryption';
 import {
   DecryptError,
   DecryptNoPasswordError,
diff --git a/src/app/op-log/encryption/encryption.spec.ts b/src/app/op-log/encryption/encryption.spec.ts
index f04e4552dc..9cc8d2dd38 100644
--- a/src/app/op-log/encryption/encryption.spec.ts
+++ b/src/app/op-log/encryption/encryption.spec.ts
@@ -10,7 +10,7 @@ import {
   clearSessionKeyCache,
   getSessionKeyCacheStats,
   setArgon2ParamsForTesting,
-} from './encryption';
+} from '@sp/sync-core';
 
 describe('Encryption', () => {
   const PASSWORD = 'super_secret_password';
@@ -110,6 +110,7 @@ describe('Encryption', () => {
 
         expect(result.plaintext).toBe(DATA);
         expect(result.wasLegacy).toBe(true);
+        expect(result.wasLegacyKdf).toBe(true);
         expect(result.migratedCiphertext).toBeDefined();
 
         // Verify migrated ciphertext is valid Argon2id
diff --git a/src/app/op-log/sync/operation-encryption.service.ts b/src/app/op-log/sync/operation-encryption.service.ts
index 254834833a..75c5dca010 100644
--- a/src/app/op-log/sync/operation-encryption.service.ts
+++ b/src/app/op-log/sync/operation-encryption.service.ts
@@ -1,5 +1,5 @@
 import { Injectable } from '@angular/core';
-import { encrypt, decrypt, encryptBatch, decryptBatch } from '../encryption/encryption';
+import { decrypt, decryptBatch, encrypt, encryptBatch } from '@sp/sync-core';
 import { SyncOperation } from '../sync-providers/provider.interface';
 import { DecryptError } from '../core/errors/sync-errors';
 
diff --git a/src/app/op-log/testing/helpers/mock-encryption.helper.ts b/src/app/op-log/testing/helpers/mock-encryption.helper.ts
index d5c76ea183..ecc298aedb 100644
--- a/src/app/op-log/testing/helpers/mock-encryption.helper.ts
+++ b/src/app/op-log/testing/helpers/mock-encryption.helper.ts
@@ -12,7 +12,7 @@
  *
  * Usage with Jasmine spyOn (recommended):
  * ```typescript
- * import * as encryptionModule from '../../encryption/encryption';
+ * import * as encryptionModule from '@sp/sync-core';
  * import { mockEncrypt, mockDecrypt } from './mock-encryption.helper';
  *
  * beforeEach(() => {
diff --git a/src/app/op-log/testing/integration/file-based-sync/edge-cases.integration.spec.ts b/src/app/op-log/testing/integration/file-based-sync/edge-cases.integration.spec.ts
index b8178bd185..35f377a493 100644
--- a/src/app/op-log/testing/integration/file-based-sync/edge-cases.integration.spec.ts
+++ b/src/app/op-log/testing/integration/file-based-sync/edge-cases.integration.spec.ts
@@ -12,10 +12,7 @@ import {
 } from '../../../core/operation.types';
 import { OperationLogStoreService } from '../../../persistence/operation-log-store.service';
 import { SyncImportFilterService } from '../../../sync/sync-import-filter.service';
-import {
-  clearSessionKeyCache,
-  setArgon2ParamsForTesting,
-} from '../../../encryption/encryption';
+import { clearSessionKeyCache, setArgon2ParamsForTesting } from '@sp/sync-core';
 
 describe('File-Based Sync Integration - Edge Cases', () => {
   let harness: FileBasedSyncTestHarness;