add task solution

src/createServer.js

@@ -1,3 +1,52 @@
-// Write code here
-// Also, you can create additional files in the src folder
-// and import (require) them here
+const http = require('http');
+const { convertToCase } = require('./convertToCase');
+const { validateRequest } = require('./helpers/errorMessages');
+const {
+  formatErrorResponse,
+  formatSuccessResponse,
+} = require('./helpers/responseFormatter');
+
+const createServer = () => {
+  return http.createServer((req, res) => {
+    const normalizedUrl = new URL(req.url, 'http://localhost:5700');
+    const params = new URLSearchParams(normalizedUrl.searchParams);
+    const text = normalizedUrl.pathname.slice(1);
+    const toCase = params.get('toCase');
+
+    res.setHeader('Content-Type', 'application/json');
+
+    const validationErrors = validateRequest(
+      text,
+      toCase ? toCase.toUpperCase() : null,
+    );
+
+    if (validationErrors.length > 0) {
+      res.statusCode = 400;
+      res.statusMessage = 'Bad Request';
+      res.end(JSON.stringify(formatErrorResponse(validationErrors)));
+
+      return;
+    }
+
+    try {
+      const targetCase = toCase.toUpperCase();
+      const convertedData = convertToCase(text, targetCase);
+      const result = formatSuccessResponse(convertedData, targetCase, text);
+
+      res.statusCode = 200;
+      res.statusMessage = 'OK';
+      res.end(JSON.stringify(result));
+    } catch (error) {
+      res.statusCode = 500;
+      res.statusMessage = 'Internal Server Error';
+
+      res.end(
+        JSON.stringify({ errors: [{ message: 'Internal Server Error' }] }),
+      );
+    }
+  });
+};
+
+module.exports = {
+  createServer,
+};

src/helpers/errorMessages.js

@@ -0,0 +1,30 @@
+const SUPPORTED_CASES = ['SNAKE', 'KEBAB', 'CAMEL', 'PASCAL', 'UPPER'];
+
+const validateRequest = (text, toCase) => {
+  const errors = [];
+
+  if (!text || text === 'favicon.ico') {
+    errors.push({
+      message:
+        'Text to convert is required. Correct request is: "/<TEXT_TO_CONVERT>?toCase=<CASE_NAME>".',
+    });
+  }
+
+  if (!toCase) {
+    errors.push({
+      message:
+        '"toCase" query param is required. Correct request is: "/<TEXT_TO_CONVERT>?toCase=<CASE_NAME>".',
+    });
+  } else if (!SUPPORTED_CASES.includes(toCase)) {
+    errors.push({
+      message:
+        'This case is not supported. Available cases: SNAKE, KEBAB, CAMEL, PASCAL, UPPER.',
+    });
+  }
+
+  return errors;
+};
+
+module.exports = {
+  validateRequest,
+};

src/helpers/responseFormatter.js

@@ -0,0 +1,19 @@
+const formatErrorResponse = (errors) => {
+  return {
+    errors,
+  };
+};
+
+const formatSuccessResponse = (conversionResult, targetCase, originalText) => {
+  return {
+    originalCase: conversionResult.originalCase,
+    targetCase,
+    originalText,
+    convertedText: conversionResult.convertedText,
+  };
+};
+
+module.exports = {
+  formatErrorResponse,
+  formatSuccessResponse,
+};