From 83acaf24242d195ae497460d9b40c50d8d642921 Mon Sep 17 00:00:00 2001
From: Vitaly Sender <vitaly.sender@gmail.com>
Date: Tue, 3 Aug 2021 14:01:34 -0400
Subject: [PATCH] AllSatisfy operator
- Added an `AllSatisfy` operator.
- Added tests.
- Updated `README`.
---
CombineExt.xcodeproj/project.pbxproj | 8 ++++
README.md | 33 ++++++++++++++
Sources/Operators/AllSatisfy.swift | 54 +++++++++++++++++++++++
Tests/AllSatisfyTests.swift | 66 ++++++++++++++++++++++++++++
4 files changed, 161 insertions(+)
create mode 100644 Sources/Operators/AllSatisfy.swift
create mode 100644 Tests/AllSatisfyTests.swift
diff --git a/CombineExt.xcodeproj/project.pbxproj b/CombineExt.xcodeproj/project.pbxproj
index fe9cb70..a96bf8a 100644
--- a/CombineExt.xcodeproj/project.pbxproj
+++ b/CombineExt.xcodeproj/project.pbxproj
@@ -37,6 +37,8 @@
C387777F24E6BF8F00FAD2D8 /* NwiseTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = C387777D24E6BF6C00FAD2D8 /* NwiseTests.swift */; };
D836234824EA9446002353AC /* MergeMany.swift in Sources */ = {isa = PBXBuildFile; fileRef = D836234724EA9446002353AC /* MergeMany.swift */; };
D836234A24EA9888002353AC /* MergeManyTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D836234924EA9888002353AC /* MergeManyTests.swift */; };
+ ECF0134D26B86DC000F1D286 /* AllSatisfy.swift in Sources */ = {isa = PBXBuildFile; fileRef = ECF0134C26B86DC000F1D286 /* AllSatisfy.swift */; };
+ ECF0135426B9B79900F1D286 /* AllSatisfyTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = ECF0135226B9B50000F1D286 /* AllSatisfyTests.swift */; };
OBJ_100 /* ZipMany.swift in Sources */ = {isa = PBXBuildFile; fileRef = OBJ_33 /* ZipMany.swift */; };
OBJ_101 /* CurrentValueRelay.swift in Sources */ = {isa = PBXBuildFile; fileRef = OBJ_35 /* CurrentValueRelay.swift */; };
OBJ_102 /* PassthroughRelay.swift in Sources */ = {isa = PBXBuildFile; fileRef = OBJ_36 /* PassthroughRelay.swift */; };
@@ -122,6 +124,8 @@
"CombineExt::CombineExtTests::Product" /* CombineExtTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; path = CombineExtTests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
D836234724EA9446002353AC /* MergeMany.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MergeMany.swift; sourceTree = "<group>"; };
D836234924EA9888002353AC /* MergeManyTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MergeManyTests.swift; sourceTree = "<group>"; };
+ ECF0134C26B86DC000F1D286 /* AllSatisfy.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AllSatisfy.swift; sourceTree = "<group>"; };
+ ECF0135226B9B50000F1D286 /* AllSatisfyTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AllSatisfyTests.swift; sourceTree = "<group>"; };
OBJ_10 /* Sink.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Sink.swift; sourceTree = "<group>"; };
OBJ_12 /* Optional.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Optional.swift; sourceTree = "<group>"; };
OBJ_14 /* Event.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Event.swift; sourceTree = "<group>"; };
@@ -238,6 +242,7 @@
isa = PBXGroup;
children = (
BF330EF724F2001F001281FC /* Internal */,
+ ECF0134C26B86DC000F1D286 /* AllSatisfy.swift */,
OBJ_17 /* Amb.swift */,
OBJ_18 /* AssignOwnership.swift */,
OBJ_19 /* AssignToMany.swift */,
@@ -286,6 +291,7 @@
OBJ_40 /* Tests */ = {
isa = PBXGroup;
children = (
+ ECF0135226B9B50000F1D286 /* AllSatisfyTests.swift */,
OBJ_41 /* AmbTests.swift */,
OBJ_42 /* AssignOwnershipTests.swift */,
OBJ_43 /* AssignToManyTests.swift */,
@@ -557,6 +563,7 @@
OBJ_127 /* CurrentValueRelayTests.swift in Sources */,
C387777F24E6BF8F00FAD2D8 /* NwiseTests.swift in Sources */,
OBJ_128 /* DematerializeTests.swift in Sources */,
+ ECF0135426B9B79900F1D286 /* AllSatisfyTests.swift in Sources */,
OBJ_129 /* FlatMapLatestTests.swift in Sources */,
OBJ_130 /* MapManyTests.swift in Sources */,
OBJ_131 /* MaterializeTests.swift in Sources */,
@@ -612,6 +619,7 @@
BF330EF924F20032001281FC /* Timer.swift in Sources */,
OBJ_101 /* CurrentValueRelay.swift in Sources */,
OBJ_102 /* PassthroughRelay.swift in Sources */,
+ ECF0134D26B86DC000F1D286 /* AllSatisfy.swift in Sources */,
OBJ_103 /* Relay.swift in Sources */,
OBJ_104 /* ReplaySubject.swift in Sources */,
);
diff --git a/README.md b/README.md
index 3f6b169..efaf80c 100644
--- a/README.md
+++ b/README.md
@@ -44,6 +44,7 @@ All operators, utilities and helpers respect Combine's publisher contract, inclu
* [ignoreFailure](#ignoreFailure)
* [mapToResult](#mapToResult)
* [flatMapBatches(of:)](#flatMapBatchesof)
+* [allSatisfy](#allSatisfy)
### Publishers
* [AnyPublisher.create](#AnypublisherCreate)
@@ -755,6 +756,38 @@ subscription = ints
.finished
```
+------
+
+### allSatisfy
+
+Returns a Boolean value indicating whether every element of a publisher `Collection` satisfies a given predicate.
+
+```swift
+let intArrayPublisher = PassthroughSubject<[Int], Never>()
+
+intArrayPublisher
+ .allSatisfy { $0.isMultiple(of: 2) }
+ .sink { print("All multiples of 2? \($0)") }
+
+intArrayPublisher.send([2, 4, 6, 8, 10])
+intArrayPublisher.send([2, 4, 6, 9, 10])
+
+let names = [Just("John"), Just("Jane"), Just("Jim"), Just("Jill"), Just("Joan")]
+
+names
+ .combineLatest()
+ .allSatisfy { $0.count <= 4 }
+ .sink { print("All short names? \($0)") }
+```
+
+#### Output
+
+```none
+All multiples of 2? true
+All multiples of 2? false
+All short names? true
+```
+
## Publishers
This section outlines some of the custom Combine publishers CombineExt provides
diff --git a/Sources/Operators/AllSatisfy.swift b/Sources/Operators/AllSatisfy.swift
new file mode 100644
index 0000000..d7cc94a
--- /dev/null
+++ b/Sources/Operators/AllSatisfy.swift
@@ -0,0 +1,54 @@
+//
+// AllSatisfy.swift
+// CombineExt
+//
+// Created by Vitaly Sender on 2/8/21.
+// Copyright © 2021 Combine Community. All rights reserved.
+//
+
+#if canImport(Combine)
+import Combine
+
+@available(OSX 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
+public extension Publisher where Output: Collection {
+ /// Returns a Boolean value indicating whether every element of a publisher `Collection` satisfies a given predicate.
+ ///
+ /// Example usages:
+ ///
+ /// ```
+ /// let intArrayPublisher = PassthroughSubject<[Int], Never>()
+ ///
+ /// intArrayPublisher
+ /// .allSatisfy { $0.isMultiple(of: 2) }
+ /// .sink { print("All multiples of 2? \($0)") }
+ ///
+ /// intArrayPublisher.send([2, 4, 6, 8, 10])
+ /// intArrayPublisher.send([2, 4, 6, 9, 10])
+ ///
+ /// // Output
+ /// All multiples of 2? true
+ /// All multiples of 2? false
+ /// ```
+ ///
+ /// ```
+ /// let names = [Just("John"), Just("Jane"), Just("Jim"), Just("Jill"), Just("Joan")]
+ ///
+ /// names
+ /// .combineLatest()
+ /// .allSatisfy { $0.count <= 4 }
+ /// .sink { print("All short names? \($0)") }
+ ///
+ /// // Output
+ /// All short names? true
+ /// ```
+ ///
+ /// - parameter predicate: A closure that takes an element of the sequence as its argument and returns a Boolean value that indicates whether the passed element satisfies a condition.
+ ///
+ /// - returns: A publisher that represents whether all elements in the original publisher `Collection` satisfy `predicate`.
+ ///
+ func allSatisfy(_ predicate: @escaping (Output.Element) -> Bool) -> AnyPublisher<Bool, Failure> {
+ map { $0.allSatisfy { predicate($0) } }
+ .eraseToAnyPublisher()
+ }
+}
+#endif
diff --git a/Tests/AllSatisfyTests.swift b/Tests/AllSatisfyTests.swift
new file mode 100644
index 0000000..5321add
--- /dev/null
+++ b/Tests/AllSatisfyTests.swift
@@ -0,0 +1,66 @@
+//
+// AllSatisfyTests.swift
+// CombineExt
+//
+// Created by Vitaly Sender on 3/8/21.
+//
+
+#if !os(watchOS)
+import XCTest
+import Combine
+
+@available(OSX 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
+final class AllSatisfyTests: XCTestCase {
+ var subscription: AnyCancellable!
+
+ func testAllSatisfyWithEmptyArray() {
+ let source = PassthroughSubject<[Int], Never>()
+ var result = false
+
+ subscription = source
+ .allSatisfy { $0.isMultiple(of: 2) }
+ .sink { result = $0 }
+
+ XCTAssertFalse(result)
+ }
+
+ func testAllSatisfyWithSingleElement() {
+ let source = PassthroughSubject<[Int], Never>()
+ var result = false
+
+ subscription = source
+ .allSatisfy { $0.isMultiple(of: 2) }
+ .sink { result = $0 }
+
+ source.send([2])
+
+ XCTAssertTrue(result)
+ }
+
+ func testAllSatisfyWithMultipleElementsFailing() {
+ let source = PassthroughSubject<[Int], Never>()
+ var result = false
+
+ subscription = source
+ .allSatisfy { $0.isMultiple(of: 2) }
+ .sink { result = $0 }
+
+ source.send([1, 4])
+
+ XCTAssertFalse(result)
+ }
+
+ func testAllSatisfyWithMultipleElementsSucceeding() {
+ let source = PassthroughSubject<[Int], Never>()
+ var result = false
+
+ subscription = source
+ .allSatisfy { $0.isMultiple(of: 2) }
+ .sink { result = $0 }
+
+ source.send([2, 4, 10])
+
+ XCTAssertTrue(result)
+ }
+}
+#endif