Adding axios.isCancel method

test/specs/api.spec.js

@@ -34,6 +34,12 @@ describe('static api', function () {
   it('should have factory method', function () {
     expect(typeof axios.create).toEqual('function');
   });
+
+  it('should have Cancel, CancelToken, and isCancel properties', function () {
+    expect(typeof axios.Cancel).toEqual('function');
+    expect(typeof axios.CancelToken).toEqual('function');
+    expect(typeof axios.isCancel).toEqual('function');
+  });
 });
 
 describe('instance api', function () {

test/specs/cancel/isCancel.spec.js

@@ -0,0 +1,12 @@
+var isCancel = require('../../../lib/cancel/isCancel');
+var Cancel = require('../../../lib/cancel/Cancel');
+
+describe('isCancel', function() {
+  it('returns true if value is a Cancel', function() {
+    expect(isCancel(new Cancel())).toBe(true);
+  });
+
+  it('returns false if value is not a Cancel', function() {
+    expect(isCancel({ foo: 'bar' })).toBe(false);
+  });
+});

test/specs/instance.spec.js

@@ -16,6 +16,7 @@ describe('instance', function () {
         'create',
         'Cancel',
         'CancelToken',
+        'isCancel',
         'all',
         'spread',
         'default'].indexOf(prop) > -1) {

test/typescript/axios.ts

@@ -230,7 +230,7 @@ const source: CancelTokenSource = axios.CancelToken.source();
 axios.get('/user', {
   cancelToken: source.token
 }).catch((thrown: AxiosError | Cancel) => {
-  if (thrown instanceof axios.Cancel) {
+  if (axios.isCancel(thrown)) {
     const cancel: Cancel = thrown;
     console.log(cancel.message);
   }