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Merge pull request #15 from sideeffect-io/feature/debounced-binding
supporting: add debounce and distinct ability to Binding
2 parents ae6c210 + d742706 commit f8c7b1c

8 files changed

Lines changed: 213 additions & 7 deletions

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‎Sources/AsyncStateMachine/AsyncStateMachine.swift‎

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@@ -7,13 +7,14 @@
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public final class AsyncStateMachine<S, E, O>: AsyncSequence, Sendable
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where S: DSLCompatible & Sendable, E: DSLCompatible & Sendable, O: DSLCompatible {
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public typealias StateSequence =
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AsyncOnEachSequence<AsyncSerialSequence<AsyncCompactScanSequence<AsyncOnEachSequence<AsyncBufferedChannel<E>>, S>>>
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public typealias Element = S
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public typealias AsyncIterator =
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AsyncOnEachSequence<AsyncSerialSequence<AsyncCompactScanSequence<AsyncOnEachSequence<AsyncBufferedChannel<E>>, S>>>.Iterator
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public typealias AsyncIterator = StateSequence.Iterator
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let initialState: S
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let eventChannel: AsyncBufferedChannel<E>
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let stateSequence: AsyncOnEachSequence<AsyncSerialSequence<AsyncCompactScanSequence<AsyncOnEachSequence<AsyncBufferedChannel<E>>, S>>>
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let stateSequence: StateSequence
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let deinitBlock: @Sendable () -> Void
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public convenience init(

‎Sources/Supporting/AsyncBufferedChannel.swift‎

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@@ -106,11 +106,13 @@ where Element: Sendable {
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}
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}
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@Sendable func send(_ element: Element) {
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@Sendable
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func send(_ element: Element) {
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self.send(.element(element))
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}
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113-
@Sendable func finish() {
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@Sendable
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func finish() {
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self.send(.termination)
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}
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‎Sources/Supporting/Binding+Debounce.swift‎

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//
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// Binding+Debounce.swift
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//
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//
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// Created by Thibault Wittemberg on 20/08/2022.
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//
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extension DispatchTimeInterval {
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var nanoseconds: UInt64 {
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switch self {
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case .nanoseconds(let value): return UInt64(value)
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case .microseconds(let value): return UInt64(value) * 1000
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case .milliseconds(let value): return UInt64(value) * 1_000_000
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case .seconds(let value): return UInt64(value) * 1_000_000_000
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case .never: return .zero
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@unknown default: return .zero
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}
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}
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}
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#if canImport(SwiftUI)
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import SwiftUI
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extension Binding {
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struct DueValue {
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let value: Value
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let dueTime: DispatchTime
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}
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public func debounce(for dueTime: DispatchTimeInterval) -> Self {
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let lastKnownValue = ManagedCriticalState<DueValue?>(nil)
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let debounceInProgress = ManagedCriticalState<Bool>(false)
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return Binding {
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self.wrappedValue
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} set: { value in
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if debounceInProgress.criticalState {
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let newValue = DueValue(value: value, dueTime: DispatchTime.now().advanced(by: dueTime))
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lastKnownValue.apply(criticalState: newValue)
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} else {
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debounceInProgress.apply(criticalState: true)
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Task {
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var timeToSleep = dueTime.nanoseconds
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var currentValue = value
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repeat {
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lastKnownValue.apply(criticalState: nil)
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try? await Task.sleep(nanoseconds: timeToSleep)
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if let lastKnownValue = lastKnownValue.criticalState {
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timeToSleep = DispatchTime.now().distance(to: lastKnownValue.dueTime).nanoseconds
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currentValue = lastKnownValue.value
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}
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} while lastKnownValue.criticalState != nil
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debounceInProgress.apply(criticalState: false)
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self.wrappedValue = currentValue
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}
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}
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}
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}
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}
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#endif

‎Sources/Supporting/Binding+Distinct.swift‎

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//
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// Binding+Distinct.swift
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//
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//
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// Created by Thibault Wittemberg on 21/08/2022.
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//
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#if canImport(SwiftUI)
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import SwiftUI
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public extension Binding where Value: Equatable {
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func distinct() -> Self {
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return Binding {
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self.wrappedValue
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} set: { value in
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guard value != self.wrappedValue else { return }
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self.wrappedValue = value
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}
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}
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}
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#endif

‎Sources/Supporting/Inject.swift‎

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@@ -5,7 +5,7 @@
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// Created by Thibault WITTEMBERG on 25/06/2022.
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//
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8-
// swiftlint:disable identifier_name void_return function_parameter_count
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// swiftlint:disable identifier_name function_parameter_count
99
public func inject<A, R>(
1010
dep a: A,
1111
in block: @Sendable @escaping (A) async -> R

‎Sources/Supporting/ThrowingInject.swift‎

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@@ -5,7 +5,7 @@
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// Created by Thibault Wittemberg on 18/08/2022.
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//
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8-
// swiftlint:disable identifier_name void_return function_parameter_count
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// swiftlint:disable identifier_name function_parameter_count
99
public func inject<A, R>(
1010
dep a: A,
1111
in block: @Sendable @escaping (A) async throws -> R

‎Tests/Supporting/Binding+DebounceTests.swift‎

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//
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// Binding+DebounceTests.swift
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//
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//
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// Created by Thibault Wittemberg on 21/08/2022.
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//
7+
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#if canImport(SwiftUI)
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import SwiftUI
10+
@testable import AsyncStateMachine
11+
import XCTest
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final class Binding_DebounceTests: XCTestCase {
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func test_debounce_filters_out_values_according_to_dueTime() {
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let lastValueSet = expectation(description: "The last value has been set in the binding")
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// | 500 1000 1500 2000 2500 |
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// | | | | | | | | | | | | |
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// timeline 0 1 2 3 4567 8
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// debounced 2 3 7 8
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22+
let events = [
23+
(0, DispatchTimeInterval.milliseconds(0)),
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(1, DispatchTimeInterval.milliseconds(250)),
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(2, DispatchTimeInterval.milliseconds(500)),
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(3, DispatchTimeInterval.milliseconds(1_000)),
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(4, DispatchTimeInterval.milliseconds(2_000)),
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(5, DispatchTimeInterval.milliseconds(2_025)),
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(6, DispatchTimeInterval.milliseconds(2_050)),
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(7, DispatchTimeInterval.milliseconds(2_075)),
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(8, DispatchTimeInterval.milliseconds(2_750))
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]
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var received = [Int]()
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// Given
37+
let sut = Binding {
38+
1
39+
} set: { value in
40+
received.append(value)
41+
if value == 8 {
42+
lastValueSet.fulfill()
43+
}
44+
}.debounce(for: .milliseconds(300))
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46+
let now = DispatchTime.now()
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48+
// When
49+
for event in events {
50+
DispatchQueue.global().asyncAfter(deadline: now.advanced(by: event.1)) {
51+
sut.wrappedValue = event.0
52+
}
53+
}
54+
55+
wait(for: [lastValueSet], timeout: 10)
56+
57+
// Then
58+
XCTAssertEqual(received, [2, 3, 7, 8])
59+
}
60+
61+
func test_nanoseconds_converts_values() {
62+
// Given
63+
let expected = [
64+
(DispatchTimeInterval.never, UInt64(0)),
65+
(DispatchTimeInterval.seconds(2), 2_000_000_000),
66+
(DispatchTimeInterval.milliseconds(3), 3_000_000),
67+
(DispatchTimeInterval.microseconds(6), 6_000),
68+
(DispatchTimeInterval.nanoseconds(9), 9)
69+
]
70+
71+
for expect in expected {
72+
// When
73+
// Then
74+
XCTAssertEqual(expect.0.nanoseconds, expect.1)
75+
}
76+
}
77+
}
78+
#endif

‎Tests/Supporting/Binding+DistinctTests.swift‎

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1+
//
2+
// Binding+DistinctTests.swift
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//
4+
//
5+
// Created by Thibault Wittemberg on 21/08/2022.
6+
//
7+
8+
#if canImport(SwiftUI)
9+
import SwiftUI
10+
@testable import AsyncStateMachine
11+
import XCTest
12+
13+
final class Binding_DistinctTests: XCTestCase {
14+
func test_distinct_calls_sets_when_input_is_different() {
15+
var value = 1
16+
var setHasBeenCalled = false
17+
18+
// Given
19+
let sut = Binding<Int> {
20+
value
21+
} set: { newValue in
22+
setHasBeenCalled = true
23+
value = newValue
24+
}.distinct()
25+
26+
// When
27+
sut.wrappedValue = 1
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// Then
30+
XCTAssertEqual(value, 1)
31+
XCTAssertFalse(setHasBeenCalled)
32+
33+
// When
34+
sut.wrappedValue = 2
35+
36+
// Then
37+
XCTAssertEqual(value, 2)
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XCTAssertTrue(setHasBeenCalled)
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}
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}
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#endif

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