Solution

src/Error.js

@@ -0,0 +1,39 @@
+class ErrorCase {
+  caseTypes = ['SNAKE', 'KEBAB', 'CAMEL', 'PASCAL', 'UPPER'];
+
+  convertErrorMessage = '/<TEXT_TO_CONVERT>?toCase=<CASE_NAME>';
+
+  originalTextError = `Text to convert is required. Correct request is: "${this.convertErrorMessage}".`;
+
+  originalCaseError = `"toCase" query param is required. Correct request is: "${this.convertErrorMessage}".`;
+
+  caseTypesError = `This case is not supported. Available cases: ${this.caseTypes.join(', ')}.`;
+
+  hasError(originalText, originalCase) {
+    return (
+      !originalText || !originalCase || !this.caseTypes.includes(originalCase)
+    );
+  }
+
+  getError(originalText, originalCase) {
+    const errors = [];
+
+    if (!originalText) {
+      errors.push(this.originalTextError);
+    }
+
+    if (!originalCase) {
+      errors.push(this.originalCaseError);
+    } else if (!this.caseTypes.includes(originalCase)) {
+      errors.push(this.caseTypesError);
+    }
+
+    return errors.map((error) => ({ message: error }));
+  }
+}
+
+const errorCase = new ErrorCase();
+
+module.exports = {
+  errorCase,
+};

src/convertToCase/convertToCase.js

@@ -14,6 +14,7 @@ const { wordsToCase } = require('./wordsToCase');
  *
  * @returns {Result}
  */
+
 function convertToCase(text, caseName) {
   const originalCase = detectCase(text);
   const words = toWords(text, originalCase);

src/convertToCase/detectCase.js

@@ -11,8 +11,6 @@ function detectCase(text) {
 
   if (text.toLowerCase() === text) {
     if (text.includes('_') || text.includes('-')) {
-      // There are no uppercase in the text, so it's one of the lower cases
-      // See if they're snake or kebab
       if (text.includes('_')) {
         return 'SNAKE';
       }

src/createServer.js

@@ -1,3 +1,47 @@
-// 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/convertToCase');
+const { errorCase } = require('./Error');
+const { sendJSONResponse } = require('./senResponse');
+
+const createServer = () => {
+  const server = http.createServer((req, res) => {
+    const url = new URL(req.url || '', `http://${req.headers.host}`);
+
+    const originalText = url.pathname.slice(1);
+    const targetCase = url.searchParams.get('toCase');
+
+    const hasError = errorCase.hasError(originalText, targetCase);
+
+    if (hasError) {
+      const errors = errorCase.getError(originalText, targetCase);
+
+      return sendJSONResponse(res, 400, { errors }, 'Bad request');
+    }
+
+    try {
+      const { originalCase, convertedText } = convertToCase(
+        originalText,
+        targetCase,
+      );
+
+      return sendJSONResponse(res, 200, {
+        originalCase,
+        targetCase,
+        originalText,
+        convertedText,
+      });
+    } catch (error) {
+      return sendJSONResponse(
+        res,
+        500,
+        { errors: { message: error.message } },
+        'Internal Server Error',
+      );
+    }
+  });
+
+  return server;
+};
+
+module.exports = { createServer };

src/main.js

@@ -1,6 +1,8 @@
 const { createServer } = require('./createServer');
 
-createServer().listen(5700, () => {
+const PORT = process.env.PORT || 5701;
+
+createServer().listen(PORT, () => {
   // eslint-disable-next-line no-console
   console.log('Server started! 🚀');
 });

src/senResponse.js

@@ -0,0 +1,13 @@
+const sendJSONResponse = (res, code, content, message) => {
+  res.statusCode = code;
+
+  if (message) {
+    res.statusMessage = message;
+  }
+
+  res.setHeader('Content-Type', 'application/json');
+
+  res.end(JSON.stringify(content));
+};
+
+module.exports = { sendJSONResponse };