Function messageHandler

lib/command/workers/runTests.js:277–352

    const testResult = await new Promise((resolve, reject) => {
      // Set up pool mode message handler FIRST before sending request
      const messageHandler = async eventData => {
        // Remove handler immediately to prevent duplicate processing
        parentPort?.off('message', messageHandler)
        
        if (eventData.type === 'TEST_ASSIGNED') {
          // In pool mode with ESM, we receive test FILE paths instead of UIDs
          // because UIDs are not stable across different mocha instances
          const testIdentifier = eventData.test

          try {
            // Create a fresh Mocha instance for each test file
            container.createMocha()
            const mocha = container.mocha()
            
            // Load only the assigned test file
            mocha.files = [testIdentifier]
            mocha.loadFiles()

            try {
              require('fs').appendFileSync('/tmp/config_listener_debug.log', `${new Date().toISOString()} [POOL] Loaded ${testIdentifier}, tests: ${mocha.suite.total()}\n`)
            } catch (e) { /* ignore */ }

            if (mocha.suite.total() > 0) {
              // Run only the tests in the current mocha suite
              // Don't use codecept.run() as it overwrites mocha.files with ALL test files
              await new Promise((resolve, reject) => {
                mocha.run(() => {
                  try {
                    require('fs').appendFileSync('/tmp/config_listener_debug.log', `${new Date().toISOString()} [POOL] Finished ${testIdentifier}\n`)
                  } catch (e) { /* ignore */ }
                  resolve()
                })
              })

              // Get the results from this specific test run
              const result = container.result()
              const currentStats = result.stats || {}

              // Calculate the difference from previous accumulated stats
              const newPasses = Math.max(0, (currentStats.passes || 0) - previousStats.passes)
              const newFailures = Math.max(0, (currentStats.failures || 0) - previousStats.failures)
              const newTests = Math.max(0, (currentStats.tests || 0) - previousStats.tests)
              const newPending = Math.max(0, (currentStats.pending || 0) - previousStats.pending)
              const newFailedHooks = Math.max(0, (currentStats.failedHooks || 0) - previousStats.failedHooks)

              // Add only the new results
              consolidatedStats.passes += newPasses
              consolidatedStats.failures += newFailures
              consolidatedStats.tests += newTests
              consolidatedStats.pending += newPending
              consolidatedStats.failedHooks += newFailedHooks

              // Update previous stats for next comparison
              previousStats = { ...currentStats }

              // Add new failures to consolidated collections
              if (result.failures && result.failures.length > allFailures.length) {
                const newFailures = result.failures.slice(allFailures.length)