TypeScript file Handling with Error Catching

TypeScript Error Handling : Exercise-4 with Solution

Write a TypeScript program that opens a non-existent file using the Node.js `fs` module. Implement error handling to catch file-not-found exceptions and display an error message.

Sample Solution:

TypeScript Code:

import * as fs from 'fs';

const filePath = 'test.txt';

fs.readFile(filePath, 'utf8', (error, data) => {
  if (error) {
    if (error.code === 'ENOENT') {
      console.error(`File not found: ${filePath}`);
    } else {
      console.error(`Error reading file: ${error.message}`);
    }
  } else {
    console.log(`File content: ${data}`);
  }
});

Explanations:

In the exercise above -

• First, import the "fs" module to work with file operations.
• Specify the 'filePath' variable with the path to a non-existent file.
• Use 'fs.readFile' to attempt reading the file asynchronously.
• In the callback function, we check for errors using if (error). If an error occurs, we check if the error code is 'ENOENT', which indicates a file-not-found error. In this case, we display a custom error message. If it's another type of error, we display the error message.
• Finally, If no error occurs, we display the file content.

Output:

File not found: test.txt

TypeScript Editor:

See the Pen TypeScript by w3resource (@w3resource) on CodePen.

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