Add STPAPIClient method to convert ssn_last_4 to a Token

Stripe/PublicHeaders/STPAPIClient.h

@@ -134,6 +134,14 @@ static NSString *const STPSDKVersion = @"18.1.0";
  */
 - (void)createTokenWithPersonalIDNumber:(NSString *)pii completion:(__nullable STPTokenCompletionBlock)completion;
 
+/**
+Converts the last 4 SSN digits into a Stripe token using the Stripe API.
+
+@param ssnLast4 The last 4 digits of the user's SSN. Cannot be nil.
+@param completion  The callback to run with the returned Stripe token (and any errors that may have occurred).
+*/
+- (void)createTokenWithSSNLast4:(NSString *)ssnLast4 completion:(STPTokenCompletionBlock)completion;
+
 @end
 
 #pragma mark Connect Accounts

Stripe/STPAPIClient.m

@@ -277,9 +277,15 @@ - (void)createTokenWithPersonalIDNumber:(NSString *)pii completion:(__nullable S
     NSMutableDictionary *params = [@{@"pii": @{ @"personal_id_number": pii }} mutableCopy];
     [[STPTelemetryClient sharedInstance] addTelemetryFieldsToParams:params];
     [self createTokenWithParameters:params completion:completion];
+    [[STPTelemetryClient sharedInstance] sendTelemetryData];}
+
+- (void)createTokenWithSSNLast4:(NSString *)ssnLast4 completion:(STPTokenCompletionBlock)completion {
+    NSMutableDictionary *params = [@{@"pii": @{ @"ssn_last_4": ssnLast4 }} mutableCopy];
+    [[STPTelemetryClient sharedInstance] addTelemetryFieldsToParams:params];
+    [self createTokenWithParameters:params completion:completion];
     [[STPTelemetryClient sharedInstance] sendTelemetryData];
 }
-
+    
 @end
 
 #pragma mark - Connect Accounts

Tests/Tests/STPPIIFunctionalTest.m

@@ -38,4 +38,20 @@ - (void)testCreatePersonallyIdentifiableInformationToken {
     [self waitForExpectationsWithTimeout:5.0f handler:nil];
 }
 
+- (void)testSSNLast4Token {
+    STPAPIClient *client = [[STPAPIClient alloc] initWithPublishableKey:@"pk_test_vOo1umqsYxSrP5UXfOeL3ecm"];
+
+    XCTestExpectation *expectation = [self expectationWithDescription:@"PII creation"];
+
+    [client createTokenWithSSNLast4:@"1234" completion:^(STPToken * _Nullable token, NSError * _Nullable error) {
+        [expectation fulfill];
+        XCTAssertNil(error, @"error should be nil %@", error.localizedDescription);
+        XCTAssertNotNil(token, @"token should not be nil");
+        XCTAssertNotNil(token.tokenId);
+        XCTAssertEqual(token.type, STPTokenTypePII);
+    }];
+
+    [self waitForExpectationsWithTimeout:5.0f handler:nil];
+}
+
 @end

Tests/recorded_network_traffic/STPPIIFunctionalTest/testCreatePersonallyIdentifiableInformationToken/post_v1_tokens_0.tail

@@ -4,25 +4,25 @@ POST
 application/json
 Content-Type: application/json
 Access-Control-Allow-Origin: *
-access-control-allow-methods: GET, POST, HEAD, OPTIONS, DELETE
 Server: nginx
+access-control-allow-methods: GET, POST, HEAD, OPTIONS, DELETE
 access-control-expose-headers: Request-Id, Stripe-Manage-Version, X-Stripe-External-Auth-Required, X-Stripe-Privileged-Session-Required
 access-control-max-age: 300
 Cache-Control: no-cache, no-store
-Date: Wed, 24 Jul 2019 23:23:07 GMT
+Date: Wed, 30 Oct 2019 23:56:38 GMT
 stripe-version: 2019-05-16
 access-control-allow-credentials: true
 Content-Length: 175
-Strict-Transport-Security: max-age=31556926; includeSubDomains; preload
 Connection: keep-alive
-request-id: req_HTETf1BQbwtL3v
+Strict-Transport-Security: max-age=31556926; includeSubDomains; preload
+request-id: req_G0mrDBE9JwOmuv
 
 {
   "object" : "token",
-  "id" : "pii_1EztnbBbvEcIpqUbJEDM98Z2",
+  "id" : "pii_1FZR1mBbvEcIpqUbR2ADMXtG",
   "livemode" : false,
-  "client_ip" : "8.21.168.117",
-  "created" : 1564010587,
+  "client_ip" : "8.21.168.115",
+  "created" : 1572479798,
   "used" : false,
   "type" : "pii"
 }

Tests/recorded_network_traffic/STPPIIFunctionalTest/testSSNLast4Token/post_v1_tokens_0.tail

@@ -0,0 +1,28 @@
+POST
+/v1/tokens$
+200
+application/json
+Content-Type: application/json
+Access-Control-Allow-Origin: *
+Server: nginx
+access-control-allow-methods: GET, POST, HEAD, OPTIONS, DELETE
+access-control-expose-headers: Request-Id, Stripe-Manage-Version, X-Stripe-External-Auth-Required, X-Stripe-Privileged-Session-Required
+access-control-max-age: 300
+Cache-Control: no-cache, no-store
+Date: Wed, 30 Oct 2019 23:56:38 GMT
+stripe-version: 2019-05-16
+access-control-allow-credentials: true
+Content-Length: 175
+Connection: keep-alive
+Strict-Transport-Security: max-age=31556926; includeSubDomains; preload
+request-id: req_TqZBbf0VIoU6HU
+
+{
+  "object" : "token",
+  "id" : "pii_1FZR1mBbvEcIpqUbmYvOI5c1",
+  "livemode" : false,
+  "client_ip" : "8.21.168.115",
+  "created" : 1572479798,
+  "used" : false,
+  "type" : "pii"
+}