Merge pull request #324 from csknns/main-XCTAssertThrowError-improvment

Change XCTAssertThrowsError function signature to rethrow when the error handler throws

Author: stmontgomery

Sources/XCTest/Public/XCTAssert.swift

@@ -377,6 +377,12 @@ public func XCTFail(_ message: String = "", file: StaticString = #file, line: UI
 }
 
 public func XCTAssertThrowsError<T>(_ expression: @autoclosure () throws -> T, _ message: @autoclosure () -> String = "", file: StaticString = #file, line: UInt = #line, _ errorHandler: (_ error: Swift.Error) -> Void = { _ in }) {
+    let rethrowsOverload: (() throws -> T, () -> String, StaticString, UInt, (Swift.Error) throws -> Void) throws -> Void = XCTAssertThrowsError
+
+    try? rethrowsOverload(expression, message, file, line, errorHandler)
+}
+
+public func XCTAssertThrowsError<T>(_ expression: @autoclosure () throws -> T, _ message: @autoclosure () -> String = "", file: StaticString = #file, line: UInt = #line, _ errorHandler: (_ error: Swift.Error) throws -> Void = { _ in }) rethrows {
     _XCTEvaluateAssertion(.throwsError, message: message(), file: file, line: line) {
         var caughtErrorOptional: Swift.Error?
         do {
@@ -386,7 +392,7 @@ public func XCTAssertThrowsError<T>(_ expression: @autoclosure () throws -> T, _
         }
 
         if let caughtError = caughtErrorOptional {
-            errorHandler(caughtError)
+            try errorHandler(caughtError)
             return .success
         } else {
             return .expectedFailure("did not throw error")

Tests/Functional/ErrorHandling/main.swift

@@ -16,6 +16,8 @@ class ErrorHandling: XCTestCase {
     static var allTests = {
         return [
             // Tests for XCTAssertThrowsError
+            ("test_shouldRethrowErrorFromHandler", test_shouldRethrowErrorFromHandler),
+            ("test_shouldNotRethrowWhenHandlerDoesNotThrow", test_shouldNotRethrowWhenHandlerDoesNotThrow),
             ("test_shouldButDoesNotThrowErrorInAssertion", test_shouldButDoesNotThrowErrorInAssertion),
             ("test_shouldThrowErrorInAssertion", test_shouldThrowErrorInAssertion),
             ("test_throwsErrorInAssertionButFailsWhenCheckingError", test_throwsErrorInAssertionButFailsWhenCheckingError),
@@ -59,6 +61,19 @@ class ErrorHandling: XCTestCase {
         throw SomeError.anError("an error message")
     }
 
+// CHECK: Test Case 'ErrorHandling.test_shouldRethrowErrorFromHandler' started at \d+-\d+-\d+ \d+:\d+:\d+\.\d+
+// CHECK: .*[/\\]ErrorHandling[/\\]main.swift:[[@LINE+3]]: error: ErrorHandling.test_shouldRethrowErrorFromHandler : XCTAssertThrowsError threw error "anError\("an error message"\)" -
+// CHECK: Test Case 'ErrorHandling.test_shouldRethrowErrorFromHandler' failed \(\d+\.\d+ seconds\)
+    func test_shouldRethrowErrorFromHandler() throws {
+        try XCTAssertThrowsError(try functionThatDoesThrowError()) {_ in try functionThatDoesThrowError() }
+    }
+
+// CHECK: Test Case 'ErrorHandling.test_shouldNotRethrowWhenHandlerDoesNotThrow' started at \d+-\d+-\d+ \d+:\d+:\d+\.\d+
+// CHECK: Test Case 'ErrorHandling.test_shouldNotRethrowWhenHandlerDoesNotThrow' passed \(\d+\.\d+ seconds\)
+    func test_shouldNotRethrowWhenHandlerDoesNotThrow() throws {
+        try XCTAssertThrowsError(try functionThatDoesThrowError()) {_ in try functionThatDoesNotThrowError() }
+    }
+
 // CHECK: Test Case 'ErrorHandling.test_shouldButDoesNotThrowErrorInAssertion' started at \d+-\d+-\d+ \d+:\d+:\d+\.\d+
 // CHECK: .*[/\\]ErrorHandling[/\\]main.swift:[[@LINE+3]]: error: ErrorHandling.test_shouldButDoesNotThrowErrorInAssertion : XCTAssertThrowsError failed: did not throw error -
 // CHECK: Test Case 'ErrorHandling.test_shouldButDoesNotThrowErrorInAssertion' failed \(\d+\.\d+ seconds\)
@@ -278,11 +293,11 @@ class ErrorHandling: XCTestCase {
 }
 
 // CHECK: Test Suite 'ErrorHandling' failed at \d+-\d+-\d+ \d+:\d+:\d+\.\d+
-// CHECK: \t Executed \d+ tests, with \d+ failures \(5 unexpected\) in \d+\.\d+ \(\d+\.\d+\) seconds
+// CHECK: \t Executed \d+ tests, with \d+ failures \(6 unexpected\) in \d+\.\d+ \(\d+\.\d+\) seconds
 
 XCTMain([testCase(ErrorHandling.allTests)])
 
 // CHECK: Test Suite '.*\.xctest' failed at \d+-\d+-\d+ \d+:\d+:\d+\.\d+
-// CHECK: \t Executed \d+ tests, with \d+ failures \(5 unexpected\) in \d+\.\d+ \(\d+\.\d+\) seconds
+// CHECK: \t Executed \d+ tests, with \d+ failures \(6 unexpected\) in \d+\.\d+ \(\d+\.\d+\) seconds
 // CHECK: Test Suite 'All tests' failed at \d+-\d+-\d+ \d+:\d+:\d+\.\d+
-// CHECK: \t Executed \d+ tests, with \d+ failures \(5 unexpected\) in \d+\.\d+ \(\d+\.\d+\) seconds
+// CHECK: \t Executed \d+ tests, with \d+ failures \(6 unexpected\) in \d+\.\d+ \(\d+\.\d+\) seconds