Throw a special error subclass when the public IP address could not be found

Author: sindresorhus

browser.js

@@ -11,6 +11,13 @@ export class CancelError extends Error {
 	}
 }
 
+export class IpNotFoundError extends Error {
+	constructor(options) {
+		super('Could not get the public IP address', options);
+		this.name = 'IpNotFoundError';
+	}
+}
+
 const defaults = {
 	timeout: 5000,
 };
@@ -83,7 +90,7 @@ const queryHttps = (version, options) => {
 			}
 		}
 
-		throw new Error('Could not find your IP address', {cause: lastError});
+		throw new IpNotFoundError({cause: lastError});
 	})();
 
 	promise.cancel = () => {

index.d.ts

@@ -1,3 +1,8 @@
+/**
+Thrown when the public IP address could not be found.
+*/
+export class IpNotFoundError extends Error {}
+
 export interface Options {
 	/**
 	Use a HTTPS check using the [icanhazip.com](https://github.com/major/icanhaz) service instead of the DNS query. [ipify.org](https://www.ipify.org) is used as a fallback if `icanhazip.com` fails. This check is much more secure and tamper-proof, but also a lot slower.

index.js

@@ -4,6 +4,13 @@ import dns from 'dns-socket';
 import got, {CancelError} from 'got';
 import isIp from 'is-ip';
 
+export class IpNotFoundError extends Error {
+	constructor(options) {
+		super('Could not get the public IP address', options);
+		this.name = 'IpNotFoundError';
+	}
+}
+
 const defaults = {
 	timeout: 5000,
 	onlyHttps: false,
@@ -129,7 +136,7 @@ const queryDns = (version, options) => {
 
 		socket.destroy();
 
-		throw new Error('Could not find your IP address', {cause: lastError});
+		throw new IpNotFoundError({cause: lastError});
 	})();
 
 	promise.cancel = () => {
@@ -183,8 +190,7 @@ const queryHttps = (version, options) => {
 				}
 			}
 
-			const errorDescription = lastError ? `: ${lastError.message}` : '';
-			throw new Error(`Could not find your IP address${errorDescription}`, {cause: lastError});
+			throw new IpNotFoundError({cause: lastError});
 		} catch (error) {
 			// Don't throw a cancellation error for consistency with DNS
 			if (!(error instanceof CancelError)) {

readme.md

@@ -64,6 +64,14 @@ Default: `5000`
 
 The time in milliseconds until a request is considered timed out.
 
+### IpNotFoundError
+
+Error thrown when the public IP address could not be found.
+
+### CancelError
+
+Error thrown when the operation was canceled.
+
 ## Maintainers
 
 - [Sindre Sorhus](https://github.com/sindresorhus)