Make waiting for multiple expectations easy (#8)

README.md

@@ -24,6 +24,25 @@ The `Expectation` vended from this library fills that gap:
 }
 ```
 
+### Waiting for multiple expectations
+
+The `Expectations` type vended from this library makes it easy to wait for multiple expectations:
+
+```swift
+@Test func testMethodEventuallyTriggersClosures() async {
+    let expectation1 = Expectation()
+    let expectation2 = Expectation()
+    let expectation3 = Expectation()
+
+    systemUnderTest.closure1 = { expectation1.fulfill() }
+    systemUnderTest.closure2 = { expectation2.fulfill() }
+    systemUnderTest.closure3 = { expectation3.fulfill() }
+    systemUnderTest.method()
+
+    await Expectations(expectation1, expectation2, expectation3).fulfillment(within: .seconds(5))
+}
+```
+
 ## Installation
 
 ### Swift Package Manager

Sources/TestingExpectation/Expectations.swift

@@ -0,0 +1,62 @@
+// MIT License
+//
+// Copyright (c) 2025 Dan Federman
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+public actor Expectations {
+	// MARK: Initialization
+
+	public init(_ expectations: [Expectation]) {
+		self.expectations = expectations
+	}
+
+	public init(_ expectations: Expectation...) {
+		self.init(expectations)
+	}
+
+	// MARK: Public
+
+	public func fulfillment(
+		within duration: Duration,
+		filePath: String = #filePath,
+		fileID: String = #fileID,
+		line: Int = #line,
+		column: Int = #column
+	) async {
+		await withTaskGroup(of: Void.self) { taskGroup in
+			for expectation in expectations {
+				taskGroup.addTask {
+					await expectation.fulfillment(
+						within: duration,
+						filePath: filePath,
+						fileID: fileID,
+						line: line,
+						column: column
+					)
+				}
+			}
+			await taskGroup.waitForAll()
+		}
+	}
+
+	// MARK: Private
+
+	private let expectations: [Expectation]
+}

Tests/TestingExpectationTests/ExpectationsTests.swift

@@ -0,0 +1,116 @@
+// MIT License
+//
+// Copyright (c) 2025 Dan Federman
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+import Testing
+
+@testable import TestingExpectation
+
+struct ExpectationsTests {
+	@Test
+	func test_fulfillment_doesNotWaitIfAlreadyFulfilled() async {
+		let expectation = Expectation(expectedCount: 0)
+		await Expectations(expectation).fulfillment(within: .seconds(10))
+	}
+
+	@MainActor // Global actor ensures Task ordering.
+	@Test
+	func test_fulfillment_waitsForFulfillmentOfSingleExpectation() async {
+		let expectation = Expectation(expectedCount: 1)
+		var hasFulfilled = false
+		let wait = Task {
+			await Expectations(expectation).fulfillment(within: .seconds(10))
+			#expect(hasFulfilled)
+		}
+		Task {
+			expectation.fulfill()
+			hasFulfilled = true
+		}
+		await wait.value
+	}
+
+	@MainActor // Global actor ensures Task ordering.
+	@Test
+	func test_fulfillment_waitsForFulfillmentOfMultipleExpectations() async {
+		let expectation1 = Expectation(expectedCount: 1)
+		let expectation2 = Expectation(expectedCount: 1)
+		let expectation3 = Expectation(expectedCount: 1)
+		var hasFulfilled = false
+		let wait = Task {
+			await Expectations(expectation1).fulfillment(within: .seconds(10))
+			#expect(hasFulfilled)
+		}
+		Task {
+			expectation1.fulfill()
+			expectation2.fulfill()
+			expectation3.fulfill()
+			hasFulfilled = true
+		}
+		await wait.value
+	}
+
+	@Test
+	func test_fulfillment_triggersFalseExpectationWhenSingleExpectationTimesOut() async {
+		await confirmation { confirmation in
+			let expectation = Expectation(
+				expectedCount: 1,
+				expect: { expectation, _, _ in
+					#expect(!expectation)
+					confirmation()
+				}
+			)
+			let systemUnderTest = Expectations(expectation)
+			await systemUnderTest.fulfillment(within: .zero)
+		}
+	}
+
+	@Test
+	func test_fulfillment_triggersFalseExpectationWhenSingleExpectationOfManyTimesOut() async {
+		await confirmation(expectedCount: 3) { confirmation in
+			let expectation1 = Expectation(
+				expectedCount: 1,
+				expect: { expectation, _, _ in
+					#expect(!expectation)
+					confirmation()
+				}
+			)
+			let expectation2 = Expectation(
+				expectedCount: 1,
+				expect: { expectation, _, _ in
+					#expect(expectation)
+					confirmation()
+				}
+			)
+			expectation2.fulfill()
+			let expectation3 = Expectation(
+				expectedCount: 1,
+				expect: { expectation, _, _ in
+					#expect(expectation)
+					confirmation()
+				}
+			)
+			expectation3.fulfill()
+
+			let systemUnderTest = Expectations(expectation1, expectation2, expectation3)
+			await systemUnderTest.fulfillment(within: .zero)
+		}
+	}
+}