Add computed properties to HTTPManagerError

* Add properties for accessing fields common to two or more variants. * Add `statusCode` property that returns the status code for all errors except for `.unexpectedContentType`. * Add `PMHTTPErrorGetStatusCode()` function for Obj-C. Fixes #60.
postmates · Apr 24, 2019 · ab9d2c3 · ab9d2c3
1 parent b2d5b92
commit ab9d2c3
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diff --git a/README.md b/README.md
@@ -413,7 +413,11 @@ work by you shall be dual licensed as above, without any additional terms or con
 #### Development
 
 * Fix a bug when parsing images where we passed the wrong value for the type identifier hint, resulting in a warning being logged to the console ([#62][]).
+* Add computed properties on `HTTPManagerError` for convenient access to the associated values (e.g. `.response`, `.body`, etc).
+* Add computed property `HTTPManagerError.statusCode` that returns the failing status code for the error, or `nil` for `.unexpectedContentType` ([#60][]).
+* Add Obj-C function `PMHTTPErrorGetStatusCode()` that returns the failing status code for the error, or `nil` for `PMHTTPErrorUnexpectedContentType` or for non-PMHTTP errors ([#60][]).
 
+[#60]: https://github.com/postmates/PMHTTP/issues/60 "HTTPManagerError should have .statusCode property · Issue #60 · postmates/PMHTTP"
 [#62]: https://github.com/postmates/PMHTTP/issues/62 "Unknown Hint Identifier for Image MIME Types · Issue #62 · postmates/PMHTTP"
 
 #### v4.3.3 (2019-04-07)

diff --git a/Sources/HTTPManager.swift b/Sources/HTTPManager.swift
@@ -1316,6 +1316,62 @@ public enum HTTPManagerError: Error, CustomStringConvertible, CustomDebugStringC
     /// - Parameter body: The body of the response, if any.
     case unexpectedRedirect(statusCode: Int, location: URL?, response: HTTPURLResponse, body: Data)
 
+    /// Returns the HTTP status code for the error.
+    ///
+    /// If the error does not represent a response with a non-successful status code (e.g.
+    /// `unexpectedContentType`), this returns `nil` instead.
+    public var statusCode: Int? {
+        switch self {
+        case .failedResponse(let statusCode, _, _, _),
+             .unexpectedRedirect(let statusCode, _, _, _):
+            return statusCode
+        case .unauthorized: return 401
+        case .unexpectedContentType: return nil
+        case .unexpectedNoContent: return 204
+        }
+    }
+
+    /// Returns the `HTTPURLResponse` for the error.
+    public var response: HTTPURLResponse {
+        switch self {
+        case .failedResponse(_, let response, _, _),
+             .unauthorized(_, let response, _, _),
+             .unexpectedContentType(_, let response, _),
+             .unexpectedNoContent(let response),
+             .unexpectedRedirect(_, _, let response, _):
+            return response
+        }
+    }
+
+    /// Returns the response body for the error, or `nil` for `.unexpectedNoContent`.
+    public var body: Data? {
+        switch self {
+        case .failedResponse(_, _, let body, _),
+             .unauthorized(_, _, let body, _),
+             .unexpectedContentType(_, _, let body),
+             .unexpectedRedirect(_, _, _, let body):
+            return body
+        case .unexpectedNoContent: return nil
+        }
+    }
+
+    /// Returns the response body for the error as a `JSON`, if possible.
+    ///
+    /// If a `.failedResponse` or `.unauthorized` response declares a `Content-Type` of
+    /// `application/json` or `text/json`, this returns the results of decoding the body as JSON.
+    /// Otherwise, or if the decoding fails, this returns `nil`.
+    public var bodyJson: JSON? {
+        switch self {
+            case .failedResponse(_, _, _, let bodyJson),
+                 .unauthorized(_, _, _, let bodyJson):
+            return bodyJson
+        case .unexpectedContentType,
+             .unexpectedNoContent,
+             .unexpectedRedirect:
+            return nil
+        }
+    }
+
     public var description: String {
         switch self {
         case let .failedResponse(statusCode, response, body, json):

diff --git a/Sources/PMHTTPError.h b/Sources/PMHTTPError.h
@@ -79,3 +79,12 @@ extern NSString * _Nonnull const PMHTTPCredentialErrorKey NS_UNAVAILABLE;
 ///       PMHTTPErrorUnexpectedRedirect in addition to \c PMHTTPErrorFailedResponse.
 NS_SWIFT_UNAVAILABLE("use pattern matching against HTTPManagerError")
 BOOL PMHTTPErrorIsFailedResponse(NSError * _Nullable error, NSInteger statusCode);
+
+/// Returns the HTTP status code from a PMHTTP error.
+///
+/// \param error The \c NSError to test.
+/// \returns An \c NSNumber containing the HTTP status code represented by the error if the error is
+/// a PMHTTP error that corresponds to a specific status code, otherwise \c nil if the error is not
+/// a PMHTTP error or is an error that represents something other than a non-successful status code.
+NS_SWIFT_UNAVAILABLE("use HTTPManagerError.statusCode")
+NSNumber * _Nullable PMHTTPErrorGetStatusCode(NSError * _Nullable error);
diff --git a/Sources/PMHTTPError.m b/Sources/PMHTTPError.m
@@ -25,19 +25,24 @@
 NSString * const PMHTTPLocationErrorKey = @"location";
 
 BOOL PMHTTPErrorIsFailedResponse(NSError * _Nullable error, NSInteger statusCode) {
-    if (![error.domain isEqualToString:PMHTTPErrorDomain]) return NO;
+    NSNumber *errorStatusCode = PMHTTPErrorGetStatusCode(error);
+    return errorStatusCode && errorStatusCode.integerValue == statusCode;
+}
+
+NSNumber * _Nullable PMHTTPErrorGetStatusCode(NSError * _Nullable error) {
+    if (![error.domain isEqualToString:PMHTTPErrorDomain]) return nil;
     switch ((PMHTTPError)error.code) {
         case PMHTTPErrorFailedResponse:
         case PMHTTPErrorUnexpectedRedirect: {
             NSNumber *errorStatusCode = error.userInfo[PMHTTPStatusCodeErrorKey];
-            return [errorStatusCode isKindOfClass:[NSNumber class]] && errorStatusCode.integerValue == statusCode;
+            return [errorStatusCode isKindOfClass:[NSNumber class]] ? errorStatusCode : nil;
         }
         case PMHTTPErrorUnauthorized:
-            return statusCode == 401;
+            return @401;
         case PMHTTPErrorUnexpectedContentType:
-            return NO;
+            return nil;
         case PMHTTPErrorUnexpectedNoContent:
-            return statusCode == 204;
+            return @204;
     }
-    return NO;
+    return nil;
 }
diff --git a/Tests/PMHTTPErrorTests.m b/Tests/PMHTTPErrorTests.m
@@ -46,6 +46,7 @@ - (void)testPMHTTPErrorIsFailedResponse {
     // unexpectedContentType
     XCTAssertFalse(PMHTTPErrorIsFailedResponse([ObjCTestSupport createUnexpectedContentTypeErrorWithContentType:@"text/plain" response:response body:[NSData data]], 500), @"unexpectedContentType");
     XCTAssertFalse(PMHTTPErrorIsFailedResponse([ObjCTestSupport createUnexpectedContentTypeErrorWithContentType:@"text/plain" response:response body:[NSData data]], response.statusCode), @"unexpectedContentType");
+    XCTAssertFalse(PMHTTPErrorIsFailedResponse([ObjCTestSupport createUnexpectedContentTypeErrorWithContentType:@"text/plain" response:response body:[NSData data]], 0), @"unexpectedContentType");
 
     // unexpectedNoContent
     XCTAssert(PMHTTPErrorIsFailedResponse([ObjCTestSupport createUnexpectedNoContentErrorWith:response], 204), @"unexpectedNoContent");
@@ -61,6 +62,26 @@ - (void)testPMHTTPErrorIsFailedResponse {
     XCTAssertFalse(PMHTTPErrorIsFailedResponse([ObjCTestSupport createUnexpectedRedirectErrorWithStatusCode:301 location:nil response:response body:[NSData data]], 304), @"unexpectedRedirect code 301");
     XCTAssertFalse(PMHTTPErrorIsFailedResponse([ObjCTestSupport createUnexpectedRedirectErrorWithStatusCode:304 location:nil response:response body:[NSData data]], 301), @"unexpectedRedirect code 304");
     XCTAssertFalse(PMHTTPErrorIsFailedResponse([ObjCTestSupport createUnexpectedRedirectErrorWithStatusCode:301 location:nil response:response body:[NSData data]], response.statusCode), @"unexpectedRedirect code 301");
+
+    // Dummy error with the userInfo from a PMHTTP error
+    NSError *dummyError = [NSError errorWithDomain:@"DummyErrorDomain" code:PMHTTPErrorFailedResponse
+                                          userInfo:[ObjCTestSupport createFailedResponseErrorWithStatusCode:500 response:response body:[NSData data] bodyJson:nil].userInfo];
+    XCTAssertFalse(PMHTTPErrorIsFailedResponse(dummyError, 500));
+    XCTAssertFalse(PMHTTPErrorIsFailedResponse(dummyError, 419));
+}
+
+- (void)testPMHTTPErrorGetStatusCode {
+    // Use a dummy response for all errors. The status code of the response doesn't matter,
+    // PMHTTPErrorGetStatusCode looks at the error keys instead.
+    NSHTTPURLResponse *response = [[NSHTTPURLResponse alloc] initWithURL:[NSURL URLWithString:@"http://example.com"] statusCode:419 HTTPVersion:nil headerFields:nil];
+
+    XCTAssertEqualObjects(PMHTTPErrorGetStatusCode([ObjCTestSupport createFailedResponseErrorWithStatusCode:500 response:response body:[NSData data] bodyJson:nil]), @500, @"failedResponse code 500");
+    XCTAssertEqualObjects(PMHTTPErrorGetStatusCode([ObjCTestSupport createFailedResponseErrorWithStatusCode:404 response:response body:[NSData data] bodyJson:nil]), @404, @"failedResponse code 404");
+    XCTAssertEqualObjects(PMHTTPErrorGetStatusCode([ObjCTestSupport createUnauthorizedErrorWith:nil response:response body:[NSData data] bodyJson:nil]), @401, @"unauthorized");
+    XCTAssertNil(PMHTTPErrorGetStatusCode([ObjCTestSupport createUnexpectedContentTypeErrorWithContentType:@"text/plain" response:response body:[NSData data]]), @"unexpectedContentType");
+    XCTAssertEqualObjects(PMHTTPErrorGetStatusCode([ObjCTestSupport createUnexpectedNoContentErrorWith:response]), @204, @"unexpectedNoContent");
+    XCTAssertEqualObjects(PMHTTPErrorGetStatusCode([ObjCTestSupport createUnexpectedRedirectErrorWithStatusCode:301 location:nil response:response body:[NSData data]]), @301, @"unexpectedRedirect code 301");
+    XCTAssertEqualObjects(PMHTTPErrorGetStatusCode([ObjCTestSupport createUnexpectedRedirectErrorWithStatusCode:304 location:nil response:response body:[NSData data]]), @304, @"unexpectedRedirect code 304");
 }
 
 @end
diff --git a/Tests/PMHTTPTests.swift b/Tests/PMHTTPTests.swift
@@ -1181,6 +1181,44 @@ final class PMHTTPTests: PMHTTPTestCase {
         }
     }
 
+    func testErrorProperties() {
+        let response = HTTPURLResponse(url: URL(string: "http://example.com")!, statusCode: 419, httpVersion: nil, headerFields: nil)!
+
+        // statusCode
+        XCTAssertEqual(HTTPManagerError.failedResponse(statusCode: 500, response: response, body: Data(), bodyJson: nil).statusCode, 500, "statusCode - failedResponse code 500")
+        XCTAssertEqual(HTTPManagerError.failedResponse(statusCode: 404, response: response, body: Data(), bodyJson: nil).statusCode, 404, "statusCode - failedResponse code 404")
+        XCTAssertEqual(HTTPManagerError.unauthorized(auth: nil, response: response, body: Data(), bodyJson: nil).statusCode, 401, "statusCode - unauthorized")
+        XCTAssertNil(HTTPManagerError.unexpectedContentType(contentType: "text/plain", response: response, body: Data()).statusCode, "statusCode - unexpectedContentType")
+        XCTAssertEqual(HTTPManagerError.unexpectedNoContent(response: response).statusCode, 204, "statusCode - unexpectedNoContent")
+        XCTAssertEqual(HTTPManagerError.unexpectedRedirect(statusCode: 301, location: nil, response: response, body: Data()).statusCode, 301, "statusCode - unexpectedRedirect code 301")
+        XCTAssertEqual(HTTPManagerError.unexpectedRedirect(statusCode: 304, location: nil, response: response, body: Data()).statusCode, 304, "statusCode - unexpectedRedirect code 304")
+
+        // response
+        XCTAssertEqual(HTTPManagerError.failedResponse(statusCode: 400, response: response, body: Data(), bodyJson: nil).response, response, "response - failedResponse")
+        XCTAssertEqual(HTTPManagerError.unauthorized(auth: nil, response: response, body: Data(), bodyJson: nil).response, response, "response - unauthorized")
+        XCTAssertEqual(HTTPManagerError.unexpectedContentType(contentType: "text/plain", response: response, body: Data()).response, response, "response - unexpectedContentType")
+        XCTAssertEqual(HTTPManagerError.unexpectedNoContent(response: response).response, response, "response - unexpectedNoContent")
+        XCTAssertEqual(HTTPManagerError.unexpectedRedirect(statusCode: 304, location: nil, response: response, body: Data()).response, response, "response - unexpectedRedirect")
+
+        // body
+        let data = "hello world".data(using: .utf8)!
+        XCTAssertEqual(HTTPManagerError.failedResponse(statusCode: 400, response: response, body: data, bodyJson: nil).body, data, "body - failedResponse")
+        XCTAssertEqual(HTTPManagerError.unauthorized(auth: nil, response: response, body: data, bodyJson: nil).body, data, "body - unauthorized")
+        XCTAssertEqual(HTTPManagerError.unexpectedContentType(contentType: "text/plain", response: response, body: data).body, data, "body - unexpectedContentType")
+        XCTAssertNil(HTTPManagerError.unexpectedNoContent(response: response).body, "body - unexpectedNoContent")
+        XCTAssertEqual(HTTPManagerError.unexpectedRedirect(statusCode: 304, location: nil, response: response, body: data).body, data, "body - unexpectedRedirect")
+
+        // bodyJson
+        let json: JSON = ["ok": true, "msg": "Hello world"]
+        XCTAssertEqual(HTTPManagerError.failedResponse(statusCode: 500, response: response, body: Data(), bodyJson: json).bodyJson, json, "bodyJson - failedResponse with json")
+        XCTAssertNil(HTTPManagerError.failedResponse(statusCode: 500, response: response, body: Data(), bodyJson: nil).bodyJson, "bodyJson - failedResponse without json")
+        XCTAssertEqual(HTTPManagerError.unauthorized(auth: nil, response: response, body: Data(), bodyJson: json).bodyJson, json, "bodyJson - unauthorized with json")
+        XCTAssertNil(HTTPManagerError.unauthorized(auth: nil, response: response, body: Data(), bodyJson: nil).bodyJson, "bodyJson - unauthorized without json")
+        XCTAssertNil(HTTPManagerError.unexpectedContentType(contentType: "text/plain", response: response, body: Data()).bodyJson, "bodyJson - unexpectedContentType")
+        XCTAssertNil(HTTPManagerError.unexpectedNoContent(response: response).bodyJson, "bodyJson - unexpectedNoContent")
+        XCTAssertNil(HTTPManagerError.unexpectedRedirect(statusCode: 304, location: nil, response: response, body: Data()).bodyJson, "bodyJson - unexpectedRedirect")
+    }
+
     func testEnvironmentWithPath() {
         HTTP.environment = HTTPManager.Environment(string: "http://\(httpServer.address)/api/v1")!
         expectationForHTTPRequest(httpServer, path: "/api/v1/foo") { request, completionHandler in