@@ -82,10 +82,17 @@ is a good chance you can immediately make use of one. If you are using `Date()`,
8282this library.
8383
8484``` swift
85- final class FeatureModel : ObservableObject {
85+ @Observable
86+ final class FeatureModel {
87+ var items: [Item] = []
88+
89+ @ObservationIgnored
8690 @Dependency (\.continuousClock ) var clock // Controllable way to sleep a task
91+ @ObservationIgnored
8792 @Dependency (\.date .now ) var now // Controllable way to ask for current date
93+ @ObservationIgnored
8894 @Dependency (\.mainQueue ) var mainQueue // Controllable scheduling on main queue
95+ @ObservationIgnored
8996 @Dependency (\.uuid ) var uuid // Controllable UUID creation
9097
9198 // ...
@@ -96,16 +103,17 @@ Once your dependencies are declared, rather than reaching out to the `Date()`, `
96103directly, you can use the dependency that is defined on your feature's model:
97104
98105``` swift
99- final class FeatureModel : ObservableObject {
106+ @Observable
107+ final class FeatureModel {
100108 // ...
101109
102110 func addButtonTapped () async throws {
103- try await self . clock .sleep (for : .seconds (1 )) // 👈 Don't use 'Task.sleep'
104- self . items .append (
111+ try await clock.sleep (for : .seconds (1 )) // 👈 Don't use 'Task.sleep'
112+ items.append (
105113 Item (
106- id : self . uuid (), // 👈 Don't use 'UUID()'
114+ id : uuid (), // 👈 Don't use 'UUID()'
107115 name : " "
108- createdAt : self . now // 👈 Don't use 'Date()'
116+ createdAt : now // 👈 Don't use 'Date()'
109117 )
110118 )
111119 }
@@ -120,23 +128,22 @@ inside the `addButtonTapped` method, you can use the [`withDependencies`][withde
120128function to override any dependencies for the scope of one single test. It's as easy as 1-2-3:
121129
122130``` swift
123- func testAdd () async throws {
124- let model = withDependencies {
131+ @Test
132+ func add () async throws {
133+ withDependencies {
125134 // 1️⃣ Override any dependencies that your feature uses.
126- $0 .clock = ImmediateClock ()
135+ $0 .clock = . immediate
127136 $0 .date .now = Date (timeIntervalSinceReferenceDate : 1234567890 )
128137 $0 .uuid = .incrementing
129138 } operation : {
130139 // 2️⃣ Construct the feature's model
131140 FeatureModel ()
132141 }
133-
134142 // 3️⃣ The model now executes in a controlled environment of dependencies,
135143 // and so we can make assertions against its behavior.
136144 try await model.addButtonTapped ()
137- XCTAssertEqual (
138- model.items ,
139- [
145+ #expect (
146+ model.items == [
140147 Item (
141148 id : UUID (uuidString : " 00000000-0000-0000-0000-000000000000" ! ,
142149 name : " "
@@ -158,19 +165,17 @@ But, controllable dependencies aren't only useful for tests. They can also be us
158165previews. Suppose the feature above makes use of a clock to sleep for an amount of time before
159166something happens in the view. If you don't want to literally wait for time to pass in order to see
160167how the view changes, you can override the clock dependency to be an "immediate" clock using the
161- [ ` withDependencies ` ] [ withdependencies-docs ] helper :
168+ ` .dependencies ` preview trait :
162169
163170``` swift
164- struct Feature_Previews : PreviewProvider {
165- static var previews: some View {
166- FeatureView (
167- model : withDependencies {
168- $0 .clock = ImmediateClock ()
169- } operation : {
170- FeatureModel ()
171- }
172- )
171+ #Preview (
172+ traits : .dependencies {
173+ $0 .continuousClock = .immediate
173174 }
175+ ) {
176+ // All access of '@Dependency(\.continuousClock)' in this preview will
177+ // use an immediate clock.
178+ FeatureView (model : FeatureModel ())
174179}
175180```
176181
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