Handling Edge Cases and Improving Our Function
In this final step, we will improve our isISOString
function to handle edge cases and make it more robust.
Common Edge Cases
When validating data in real applications, you need to handle various unexpected inputs. Let us examine some edge cases:
- Empty strings
- Non-string values (null, undefined, numbers, objects)
- Different timezone representations
Enhancing Our Function
Let us update our isISODate.js
file to handle these edge cases:
- Open the
isISODate.js
file in the WebIDE
- Replace the existing code with this improved version:
/**
* Checks if a string is a valid ISO 8601 formatted date string
* @param {string} val - The string to check
* @return {boolean} - Returns true if the string is in ISO format, false otherwise
*/
const isISOString = (val) => {
// Check if input is a string
if (typeof val !== "string") {
return false;
}
// Check if string is empty
if (val.trim() === "") {
return false;
}
try {
// Create a Date object from the input string
const d = new Date(val);
// Check if the date is valid and if the ISO string matches the original
return !Number.isNaN(d.valueOf()) && d.toISOString() === val;
} catch (error) {
// If any error occurs during validation, return false
return false;
}
};
// Export the function
module.exports = isISOString;
This improved function now:
- Checks if the input is a string before processing
- Handles empty strings
- Uses a try-catch block to handle any errors that might occur
- Still performs our core validation logic
Testing Our Improved Function
Let us create one final test file to verify our improved function with edge cases:
- Create a new file named
edgeCaseTester.js
- Add the following code:
// Import our improved isISOString function
const isISOString = require("./isISODate");
// Function to test and display results
function testCase(description, value) {
console.log(`Testing: ${description}`);
console.log(`Input: ${value === "" ? "(empty string)" : value}`);
console.log(`Type: ${typeof value}`);
console.log(`Is ISO Format: ${isISOString(value)}`);
console.log("-----------------------");
}
// Test with various edge cases
testCase("Valid ISO date", "2023-05-12T14:30:15.123Z");
testCase("Empty string", "");
testCase("Null value", null);
testDate("Undefined value", undefined);
testCase("Number value", 12345);
testCase("Object value", {});
testCase("Current date as ISO string", new Date().toISOString());
- Run the test file:
node edgeCaseTester.js
Real-World Application
In a real application, our isISOString
function could be used in scenarios like:
- Validating user input in a date field
- Checking dates received from external APIs
- Ensuring consistent date format in a database
- Data validation before processing
For example, in a form validation function:
function validateForm(formData) {
// Other validations...
if (formData.startDate && !isISOString(formData.startDate)) {
return {
valid: false,
error: "Start date must be in ISO format"
};
}
// More validations...
return { valid: true };
}
The improved function is now robust enough to handle unexpected inputs and provide reliable validation for ISO formatted date strings.