Function parseRerenderLogs

cli/src/__tests__/test-utils.ts:181–221

(logPath: string)

 * Parse re-render logs from the CLI debug log file
 */
export function parseRerenderLogs(logPath: string): RerenderLogEntry[] {
  const entries: RerenderLogEntry[] = []

  try {
    const content = fs.readFileSync(logPath, 'utf-8')
    const lines = content.split('\n').filter((line) => line.trim())

    for (const line of lines) {
      try {
        const parsed = JSON.parse(line)

        // Check if this is a re-render log entry
        if (
          parsed.msg &&
          typeof parsed.msg === 'string' &&
          parsed.msg.includes('render #')
        ) {
          // Extract component name from msg like "MessageBlock render #2 [user-123]: 2 props changed"
          const msgMatch = parsed.msg.match(
            /^(\w+) render #(\d+) \[([^\]]+)\]/,
          )
          if (msgMatch && parsed.data) {
            entries.push({
              timestamp: parsed.timestamp,
              componentName: msgMatch[1],
              messageId: parsed.data.id || msgMatch[3],
              renderCount: parseInt(msgMatch[2], 10),
              changedProps: parsed.data.changedProps || [],
            })
          }
        }
      } catch {
        // Skip malformed lines
      }
    }
  } catch {
    // File doesn't exist or can't be read
  }

  return entries
}

/**
 * Analyze re-render logs and return aggregated statistics