Fix destination parsing on some platforms and add support to stop traceroute

README.md

@@ -34,6 +34,11 @@ try {
         });
 
     tracer.trace('github.com');
+
+    // and you can terminate traceroute by calling `kill` method
+    setTimeout(() => {
+        tracer.kill()
+    }, 5000)
 } catch (ex) {
     console.log(ex);
 }

src/process.ts

@@ -2,7 +2,8 @@ import events from 'events';
 import readline from 'readline';
 import validator from 'validator';
 
-import { spawn } from 'child_process';
+import { ChildProcessWithoutNullStreams, spawn } from 'child_process';
+import { Readable } from 'stream';
 
 export interface Hop {
     hop: number;
@@ -13,45 +14,60 @@ export interface Hop {
 }
 
 export abstract class Process extends events.EventEmitter {
+    process: ChildProcessWithoutNullStreams|null = null
+
     constructor(private command: string, private args: string[]) {
         super();
     }
 
+    private readProcessStd(input: Readable) {
+        let isDestinationCaptured = false
+        readline.createInterface({
+            input,
+            terminal: false
+        })
+        .on('line', (line) => {
+            if (!isDestinationCaptured) {
+                const destination = this.parseDestination(line);
+                if (destination !== null) {
+                    this.emit('destination', destination);
+
+                    isDestinationCaptured = true;
+                }
+            }
+
+            const hop = this.parseHop(line);
+            if (hop !== null) {
+                this.emit('hop', hop);
+            }
+        });
+    }
+
     public trace(domainName: string): void {
         if (!this.isValidDomainName(domainName)) {
             throw "Invalid domain name or IP address";
         }
 
         this.args.push(domainName);
 
-        const process = spawn(this.command, this.args);
-        process.on('close', (code) => {
+        this.process = spawn(this.command, this.args);
+        this.process.on('close', (code) => {
             this.emit('close', code);
         });
 
-        this.emit('pid', process.pid);
-
-        let isDestinationCaptured = false;
-        if (process.pid) {
-            readline.createInterface({
-                    input: process.stdout,
-                    terminal: false
-                })
-                .on('line', (line) => {
-                    if (!isDestinationCaptured) {
-                        const destination = this.parseDestination(line);
-                        if (destination !== null) {
-                            this.emit('destination', destination);
+        this.emit('pid', this.process.pid);
 
-                            isDestinationCaptured = true;
-                        }
-                    }
+        if (this.process.pid) {
+            this.readProcessStd(this.process.stdout)
+            this.readProcessStd(this.process.stderr)
+        }
+    }
 
-                    const hop = this.parseHop(line);
-                    if (hop !== null) {
-                        this.emit('hop', hop);
-                    }
-                });
+    public kill(signal?: NodeJS.Signals | number) {
+        if (this.process) {
+            const result = this.process.kill(signal)
+            this.removeAllListeners()
+            return result
         }
     }
 

test/index.spec.ts

@@ -3,29 +3,42 @@ import validator from 'validator';
 import Traceroute from '../src/index';
 
 describe('Traceroute', () => {
-  it('should verify pid, destination, hops and close code', (wait) => {
-    const tracer = new Traceroute();
-
-    tracer
-        .on('pid', (pid) => {
-            expect(Number.isInteger(pid)).toBeTruthy();
-        })
-        .on('destination', (destination) => {
-            expect(validator.isIP(destination)).toBeTruthy();
-        })
-        .on('hop', (hopObj) => {
-            const { hop, ip, rtt1 } = hopObj;
-
-            expect(Number.isInteger(hop)).toBeTruthy();
-            expect(validator.isIP(ip) || ip === '*').toBeTruthy();
-            expect(/^\d+\.\d+\sms$/.test(rtt1) || rtt1 === '*').toBeTruthy();
-        })
-        .on('close', (code) => {
-            expect(Number.isInteger(code)).toBeTruthy();
-
-            wait();
-        });
-
-    tracer.trace('github.com');
-  }, 60000);
-});
+    it('should verify pid, destination, hops and close code', (wait) => {
+        const tracer = new Traceroute();
+
+        tracer
+            .on('pid', (pid) => {
+                expect(Number.isInteger(pid)).toBeTruthy();
+            })
+            .on('destination', (destination) => {
+                expect(validator.isIP(destination)).toBeTruthy();
+            })
+            .on('hop', (hopObj) => {
+                const { hop, ip, rtt1 } = hopObj;
+
+                expect(Number.isInteger(hop)).toBeTruthy();
+                expect(validator.isIP(ip) || ip === '*').toBeTruthy();
+                expect(/^\d+\.\d+\sms$/.test(rtt1) || rtt1 === '*').toBeTruthy();
+            })
+            .on('close', (code) => {
+                expect(Number.isInteger(code)).toBeTruthy();
+
+                wait();
+            });
+
+        tracer.trace('github.com');
+    }, 60000);
+
+    it('should exit trace by calling kill method', (done) => {
+        const tracer = new Traceroute();
+
+        tracer.trace('github.com');
+
+        setTimeout(() => {
+            const killResult = tracer.kill()
+            expect(tracer.process?.killed).toBeTruthy()
+            expect(killResult).toBeTruthy()
+            done()
+        }, 5000)
+    }, 10000);
+});