fix: User Story #4 - Correct TypeScript Module and Type Imports

src/tools/advanced-caching/cache-compression.ts

@@ -470,7 +470,7 @@ export class CacheCompressionTool {
       timestamp: Date.now(),
     };
 
-    const metadataBuffer = JSON.stringify(metadata);
+    const metadataBuffer = Buffer.from(JSON.stringify(metadata), 'utf-8');
     const metadataLength = Buffer.allocUnsafe(4);
     metadataLength.writeUInt32LE(metadataBuffer.length, 0);
 
@@ -1011,7 +1011,7 @@ export class CacheCompressionTool {
       // Replace repeated strings with dictionary references
       const compressed = this.compressWithDictionary(obj, dict);
 
-      return JSON.stringify(compressed);
+      return Buffer.from(JSON.stringify(compressed), 'utf-8');
     } catch {
       // Not JSON, just use gzip
       return Buffer.from(str);
@@ -1032,7 +1032,7 @@ export class CacheCompressionTool {
           compressed.data,
           dict,
         );
-        return JSON.stringify(decompressed);
+        return Buffer.from(JSON.stringify(decompressed), 'utf-8');
       }
 
       return data;
@@ -1272,7 +1272,7 @@ export class CacheCompressionTool {
     } else if (typeof data === "string") {
       return Buffer.from(data, "utf-8");
     } else {
-      return JSON.stringify(data);
+      return Buffer.from(JSON.stringify(data), 'utf-8');
     }
   }
 
@@ -1292,7 +1292,7 @@ export class CacheCompressionTool {
             active: i % 2 === 0,
           })),
         };
-        return JSON.stringify(obj);
+        return Buffer.from(JSON.stringify(obj), 'utf-8');
       }
 
       case "text": {

src/tools/api-database/smart-cache-api.ts

@@ -241,9 +241,9 @@ export class SmartCacheAPI {
     }
 
     const cacheKey = this.generateCacheKey(options.request, options);
-    const cachedBuffer = this.cache.get(cacheKey);
-    const cached = cachedBuffer
-      ? this.deserializeCachedResponse(cachedBuffer)
+    const cachedString = this.cache.get(cacheKey);
+    const cached = cachedString
+      ? this.deserializeCachedResponse(Buffer.from(cachedString, 'utf-8'))
       : null;
 
     // Update stats
@@ -379,9 +379,9 @@ export class SmartCacheAPI {
 
         for (const key of allKeys) {
           if (regex.test(key)) {
-            const cachedBuffer = this.cache.get(key);
-            const cached = cachedBuffer
-              ? this.deserializeCachedResponse(cachedBuffer)
+            const cachedString = this.cache.get(key);
+            const cached = cachedString
+              ? this.deserializeCachedResponse(Buffer.from(cachedString, 'utf-8'))
               : null;
             if (cached) {
               totalSize += cached.size;
@@ -402,9 +402,9 @@ export class SmartCacheAPI {
         const allKeysForTags = this.getAllCacheKeys();
 
         for (const key of allKeysForTags) {
-          const cachedBuffer = this.cache.get(key);
-          const cached = cachedBuffer
-            ? this.deserializeCachedResponse(cachedBuffer)
+          const cachedString = this.cache.get(key);
+          const cached = cachedString
+            ? this.deserializeCachedResponse(Buffer.from(cachedString, 'utf-8'))
             : null;
           if (cached && cached.tags) {
             const hasMatchingTag = cached.tags.some((tag: string) =>
@@ -422,9 +422,9 @@ export class SmartCacheAPI {
       case "manual":
         if (options.request) {
           const cacheKey = this.generateCacheKey(options.request, options);
-          const cachedBuffer = this.cache.get(cacheKey);
-          const cached = cachedBuffer
-            ? this.deserializeCachedResponse(cachedBuffer)
+          const cachedString = this.cache.get(cacheKey);
+          const cached = cachedString
+            ? this.deserializeCachedResponse(Buffer.from(cachedString, 'utf-8'))
             : null;
           if (cached) {
             totalSize += cached.size;
@@ -440,9 +440,9 @@ export class SmartCacheAPI {
         const now = Date.now();
 
         for (const key of allKeysForTime) {
-          const cachedBuffer = this.cache.get(key);
-          const cached = cachedBuffer
-            ? this.deserializeCachedResponse(cachedBuffer)
+          const cachedString = this.cache.get(key);
+          const cached = cachedString
+            ? this.deserializeCachedResponse(Buffer.from(cachedString, 'utf-8'))
             : null;
           if (cached) {
             const age = Math.floor((now - cached.timestamp) / 1000);

src/tools/api-database/smart-migration.test.ts

@@ -0,0 +1,194 @@
+/**
+ * Unit Tests for Smart Migration Tool
+ * Testing import corrections and core functionality
+ */
+
+import { describe, it, expect, beforeEach } from '@jest/globals';
+import { SmartMigration, getSmartMigration, runSmartMigration } from './smart-migration';
+import { CacheEngine } from '../../core/cache-engine';
+import { TokenCounter } from '../../core/token-counter';
+import { MetricsCollector } from '../../core/metrics';
+import { tmpdir } from 'os';
+import { join } from 'path';
+
+describe('Smart Migration - Import Type Corrections', () => {
+  let cacheEngine: CacheEngine;
+  let tokenCounter: TokenCounter;
+  let metricsCollector: MetricsCollector;
+  let smartMigration: SmartMigration;
+
+  beforeEach(() => {
+    // Initialize dependencies - verifying that imports work as values
+    cacheEngine = new CacheEngine(join(tmpdir(), '.test-cache', 'test.db'), 100);
+    tokenCounter = new TokenCounter();
+    metricsCollector = new MetricsCollector();
+    smartMigration = new SmartMigration(cacheEngine, tokenCounter, metricsCollector);
+  });
+
+  describe('Class Instantiation', () => {
+    it('should instantiate SmartMigration with TokenCounter as value', () => {
+      expect(smartMigration).toBeInstanceOf(SmartMigration);
+      expect(tokenCounter).toBeInstanceOf(TokenCounter);
+    });
+
+    it('should instantiate SmartMigration with MetricsCollector as value', () => {
+      expect(metricsCollector).toBeInstanceOf(MetricsCollector);
+    });
+
+    it('should instantiate SmartMigration with CacheEngine as value', () => {
+      expect(cacheEngine).toBeInstanceOf(CacheEngine);
+    });
+  });
+
+  describe('Factory Function', () => {
+    it('should create SmartMigration instance via factory function', () => {
+      const instance = getSmartMigration(cacheEngine, tokenCounter, metricsCollector);
+      expect(instance).toBeInstanceOf(SmartMigration);
+    });
+  });
+
+  describe('Migration List Action', () => {
+    it('should list migrations', async () => {
+      const result = await smartMigration.run({ action: 'list', limit: 5 });
+
+      expect(result).toBeDefined();
+      expect(result.result).toBeDefined();
+      expect(result.tokens).toBeDefined();
+      expect(result.tokens.baseline).toBeGreaterThan(0);
+      expect(result.tokens.actual).toBeGreaterThan(0);
+    });
+
+    it('should return token reduction metrics', async () => {
+      const result = await smartMigration.run({ action: 'list' });
+
+      expect(result.tokens.reduction).toBeGreaterThanOrEqual(0);
+      expect(result.tokens.saved).toBeGreaterThanOrEqual(0);
+    });
+  });
+
+  describe('Migration Status Action', () => {
+    it('should return migration status summary', async () => {
+      const result = await smartMigration.run({ action: 'status' });
+
+      expect(result).toBeDefined();
+      expect(result.result).toContain('Status');
+      expect(result.cached).toBe(false);
+    });
+  });
+
+  describe('Migration History Action', () => {
+    it('should return migration history', async () => {
+      const result = await smartMigration.run({ action: 'history', limit: 10 });
+
+      expect(result).toBeDefined();
+      expect(result.result).toBeDefined();
+      expect(result.executionTime).toBeGreaterThanOrEqual(0);
+    });
+  });
+
+  describe('Generate Migration Action', () => {
+    it('should generate migration file', async () => {
+      const result = await smartMigration.run({
+        action: 'generate',
+        migrationId: 'test_migration'
+      });
+
+      expect(result).toBeDefined();
+      expect(result.result).toContain('test_migration');
+    });
+  });
+
+  describe('Rollback Migration Action', () => {
+    it('should rollback migration', async () => {
+      const result = await smartMigration.run({
+        action: 'rollback',
+        migrationId: 'test_rollback',
+        direction: 'down'
+      });
+
+      expect(result).toBeDefined();
+      expect(result.result).toContain('Rollback');
+    });
+  });
+
+  describe('Caching Behavior', () => {
+    it('should cache read-only operations', async () => {
+      const result1 = await smartMigration.run({ action: 'list' });
+      const result2 = await smartMigration.run({ action: 'list' });
+
+      expect(result1).toBeDefined();
+      expect(result2).toBeDefined();
+      // Second call may be cached (implementation-dependent)
+    });
+
+    it('should respect force flag to bypass cache', async () => {
+      const result1 = await smartMigration.run({ action: 'list', force: false });
+      const result2 = await smartMigration.run({ action: 'list', force: true });
+
+      expect(result1).toBeDefined();
+      expect(result2).toBeDefined();
+      expect(result2.cached).toBe(false);
+    });
+  });
+
+  describe('Error Handling', () => {
+    it('should throw error for invalid action', async () => {
+      await expect(
+        smartMigration.run({ action: 'invalid' as any })
+      ).rejects.toThrow();
+    });
+
+    it('should throw error when migrationId missing for rollback', async () => {
+      await expect(
+        smartMigration.run({ action: 'rollback' })
+      ).rejects.toThrow('migrationId is required');
+    });
+
+    it('should throw error when migrationId missing for generate', async () => {
+      await expect(
+        smartMigration.run({ action: 'generate' })
+      ).rejects.toThrow('migrationId is required');
+    });
+  });
+
+  describe('CLI Function', () => {
+    it('should run migration via CLI function', async () => {
+      const result = await runSmartMigration({ action: 'status' });
+
+      expect(result).toBeDefined();
+      expect(typeof result).toBe('string');
+      expect(result).toContain('Status');
+    });
+  });
+});
+
+describe('Import Type Verification', () => {
+  it('should verify TokenCounter can be instantiated', () => {
+    const counter = new TokenCounter();
+    expect(counter).toBeInstanceOf(TokenCounter);
+
+    const result = counter.count('test string');
+    expect(result).toBeDefined();
+    expect(result.tokens).toBeGreaterThan(0);
+  });
+
+  it('should verify MetricsCollector can be instantiated', () => {
+    const metrics = new MetricsCollector();
+    expect(metrics).toBeInstanceOf(MetricsCollector);
+
+    metrics.record({
+      operation: 'test',
+      duration: 100,
+      success: true,
+      cacheHit: false,
+      inputTokens: 10,
+      outputTokens: 5,
+      savedTokens: 0
+    });
+  });
+
+  it('should verify CacheEngine can be instantiated', () => {
+    const cache = new CacheEngine(join(tmpdir(), '.test-cache-verify', 'test.db'), 100);
+    expect(cache).toBeInstanceOf(CacheEngine);
+  });
+});

src/tools/api-database/smart-migration.ts

@@ -19,10 +19,7 @@
  */
 
 import { createHash } from "crypto";
-import type { CacheEngine } from "../../core/cache-engine";
-import type { TokenCounter } from "../../core/token-counter";
-import type { MetricsCollector } from "../../core/metrics";
-import { CacheEngine as CacheEngineClass } from "../../core/cache-engine";
+import { CacheEngine, CacheEngine as CacheEngineClass } from "../../core/cache-engine";
 import { TokenCounter } from "../../core/token-counter";
 import { MetricsCollector } from "../../core/metrics";