Add dynamic pricing E2E test suite with Playwright

Implement comprehensive E2E tests to validate the surge pricing pipeline:
- Test SimpleSurgePricer with configurable thresholds (high=3, surge=1.5x)
- Verify discount pricing when demand is below low_threshold
- Test multi-product differential pricing based on demand signals
- Validate price propagation from pipeline through Redis to API

Test infrastructure:
- Playwright configuration with custom fixtures
- Python pipeline worker for direct test execution (bypasses Airflow)
- API client for event ingestion and price verification
- Event generator for creating realistic interaction sequences
- docker-compose.e2e.yml with minimal services for testing

e2e/lib/pipeline-runner.ts

@@ -0,0 +1,152 @@
+import { spawn } from 'child_process';
+import path from 'path';
+import { testConfig } from '../playwright.config';
+
+/**
+ * Pipeline execution result
+ */
+export interface PipelineResult {
+  success: boolean;
+  interactions_count: number;
+  products_count: number;
+  prices_published: boolean;
+  prices?: Array<{
+    productId: string;
+    current_price: number;
+    base_price: number;
+    optimal_price: number;
+    demand_score: number;
+  }>;
+  timestamp?: string;
+  message?: string;
+  error?: string;
+}
+
+/**
+ * Pipeline configuration options
+ */
+export interface PipelineOptions {
+  storeMode?: 'hotel' | 'airline';
+  highThreshold?: number;
+  lowThreshold?: number;
+  surgeMultiplier?: number;
+  discountMultiplier?: number;
+  dryRun?: boolean;
+}
+
+/**
+ * Execute the pricing pipeline to update prices based on current events
+ */
+export async function runPricingPipeline(options: PipelineOptions = {}): Promise<PipelineResult> {
+  const {
+    storeMode = 'hotel',
+    highThreshold = testConfig.pricing.highThreshold,
+    lowThreshold = testConfig.pricing.lowThreshold,
+    surgeMultiplier = testConfig.pricing.surgeMultiplier,
+    discountMultiplier = testConfig.pricing.discountMultiplier,
+    dryRun = false,
+  } = options;
+
+  const workerPath = path.join(__dirname, 'pipeline-worker.py');
+
+  const args = [
+    workerPath,
+    '--store-mode', storeMode,
+    '--high-threshold', String(highThreshold),
+    '--low-threshold', String(lowThreshold),
+    '--surge-multiplier', String(surgeMultiplier),
+    '--discount-multiplier', String(discountMultiplier),
+    '--json-output',
+  ];
+
+  if (dryRun) {
+    args.push('--dry-run');
+  }
+
+  return new Promise((resolve, reject) => {
+    const python = spawn('python3', args, {
+      env: {
+        ...process.env,
+        BACKEND_URL: testConfig.backendUrl,
+        REDIS_HOST: testConfig.redisHost,
+        REDIS_PORT: String(testConfig.redisPort),
+        KAFKA_HOST: testConfig.kafkaHost,
+        KAFKA_PORT: String(testConfig.kafkaPort),
+      },
+    });
+
+    let stdout = '';
+    let stderr = '';
+
+    python.stdout.on('data', (data) => {
+      stdout += data.toString();
+    });
+
+    python.stderr.on('data', (data) => {
+      stderr += data.toString();
+      // Log pipeline output for debugging
+      console.log('[Pipeline]', data.toString().trim());
+    });
+
+    python.on('close', (code) => {
+      if (code === 0) {
+        try {
+          // Find JSON output in stdout (last JSON object)
+          const jsonMatch = stdout.match(/\{[\s\S]*\}$/);
+          if (jsonMatch) {
+            const result = JSON.parse(jsonMatch[0]);
+            resolve(result);
+          } else {
+            resolve({
+              success: true,
+              interactions_count: 0,
+              products_count: 0,
+              prices_published: false,
+              message: 'Pipeline completed but no JSON output',
+            });
+          }
+        } catch (parseError) {
+          resolve({
+            success: true,
+            interactions_count: 0,
+            products_count: 0,
+            prices_published: false,
+            message: 'Pipeline completed but output not parseable',
+          });
+        }
+      } else {
+        reject(new Error(`Pipeline exited with code ${code}: ${stderr}`));
+      }
+    });
+
+    python.on('error', (error) => {
+      reject(new Error(`Failed to start pipeline: ${error.message}`));
+    });
+  });
+}
+
+/**
+ * Wait for prices to be updated in Redis and available via the pricing API
+ */
+export async function waitForPriceUpdate(
+  checkFn: () => Promise<boolean>,
+  maxWaitMs: number = testConfig.timing.maxPriceWait,
+  intervalMs: number = testConfig.timing.priceCheckInterval
+): Promise<boolean> {
+  const startTime = Date.now();
+
+  while (Date.now() - startTime < maxWaitMs) {
+    try {
+      const updated = await checkFn();
+      if (updated) {
+        return true;
+      }
+    } catch (error) {
+      // Ignore errors during polling
+    }
+
+    await new Promise(resolve => setTimeout(resolve, intervalMs));
+  }
+
+  return false;
+}