Android Kotlin Flows - Revision history

Iwiseman: /* The Unit Test */

2025-03-18T22:32:02Z

The Unit Test

@@ Line 201: / Line 201: @@
          viewModel = FlowyViewModel(testDispatchers)
          Dispatchers.setMain(testDispatchers.testDispatcher)
+     }
@@ Line 236: / Line 241: @@
+}
 </syntaxhighlight>

2025-03-18T22:17:24Z

The Unit Test

← Older revision		Revision as of 22:17, 18 March 2025
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	==The Unit Test==		==The Unit Test==
	Thought this would be a straight swap but it wasn't. In the original code the co-routines use '''runBlocking''' but this does not provide advanceTimeBy so we need to instead use '''runTest'''. The other thing was, and the reason I do not feel I have solved completely, I had to set the main dispatcher to the testDispatcher because the first test, tests the ViewModel that specifically uses the mainDispatcher. Not doing so results in<br>		Thought this would be a straight swap but it wasn't. In the original code the co-routines use '''runBlocking''' but this does not provide advanceTimeBy so we need to instead use '''runTest'''. The other thing was, and the reason I do not feel I have solved completely, I had to set the main dispatcher to the testDispatcher because the first test, tests the ViewModel that specifically uses the mainDispatcher. Not doing so results in<br>
	[[File:Android Dispatcher.png]]<br>. My suspicion is that the test uses a different dispatcher and causes the issue.		[[File:Android Dispatcher.png]]<br>
			My suspicion is that the test uses a different dispatcher and causes the issue<br>
	<syntaxhighlight lang="kotlin">		<syntaxhighlight lang="kotlin">
	@ExperimentalCoroutinesApi		@ExperimentalCoroutinesApi

2025-03-18T22:16:53Z

Unit Testing Flows

2025-03-18T04:11:21Z

State Flow and Shared Flow

← Older revision		Revision as of 04:11, 18 March 2025
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	</syntaxhighlight>		</syntaxhighlight>
	State Flow are events you need to keep. Shared Flows are for one time events		State Flow are events you need to keep. Shared Flows are for one time events
			=Unit Testing Flows=
			The libraries he liked to use were
			*app.cash.turbine
			*com.google.truth
			*org.jetbrains.kotlinx-coroutines-test
			I did have a problem with
			<syntaxhighlight lang="groovy">
			testImplementation(libs.turbine)
			testImplementation(libs.truth)
			testImplementation(libs.kotlinx.coroutines.test)
			</syntaxhighlight>

2025-03-18T02:58:23Z

State Flow and Shared Flow

← Older revision		Revision as of 02:58, 18 March 2025
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	}		}
	</syntaxhighlight>		</syntaxhighlight>
			State Flow are events you need to keep. Shared Flows are for one time events

2025-03-18T02:43:39Z

State Flow and Shared Flow

← Older revision		Revision as of 02:43, 18 March 2025
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	=State Flow and Shared Flow=		=State Flow and Shared Flow=
	State Flows are hot flows, and are used in the ViewModel to store view state. If the device is rotated we need something to get the original UI state from. We see this used this the following		State Flows are hot flows, and are used in the ViewModel to store view state. If the device is rotated we need something to get the original UI state from. We see this used this the following
			<syntaxhighlight lang="kotlin">
			private val _stateFlow = MutableStateFlow(0)
			val stateFlow = _stateFlow.asStateFlow()

			fun increase() {
			_stateFlow.value += 1
			}
			</syntaxhighlight>

2025-03-18T02:41:08Z

State Flow and Shared Flow

← Older revision		Revision as of 02:41, 18 March 2025
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	</syntaxhighlight>		</syntaxhighlight>
	=State Flow and Shared Flow=		=State Flow and Shared Flow=
	State Flows are hot flows, and are used in the ViewModel to store view state. If the device is rotated we need something to get the original UI state from.		State Flows are hot flows, and are used in the ViewModel to store view state. If the device is rotated we need something to get the original UI state from. We see this used this the following

2025-03-18T02:40:42Z

Simple Example

← Older revision		Revision as of 02:40, 18 March 2025
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	This is a page to capture anything important about kotlin flows. This very similar to RxJava		This is a page to capture anything important about kotlin flows. This very similar to RxJava
	=Simple Example=		=Simple Example=
	Note this code would not be executed, if there are no subscribers like RxJava		Note '''flow''' this code would not be executed as it is a '''cold flow''', if there are no subscribers like RxJava
	<syntaxhighlight lang="kotlin">		<syntaxhighlight lang="kotlin">
	val countDownFlow = flow<Int> {		val countDownFlow = flow<Int> {
Line 30:		Line 30:
	</syntaxhighlight>		</syntaxhighlight>
	We can use collectLatest which will only output the latest state		We can use collectLatest which will only output the latest state

	=Flow Operators=		=Flow Operators=
	Like RxJava there are a billion operators. Here is filter.		Like RxJava there are a billion operators. Here is filter.

2025-03-18T02:39:41Z

State Flow and Shared Flow

← Older revision		Revision as of 02:39, 18 March 2025
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	</syntaxhighlight>		</syntaxhighlight>
	=State Flow and Shared Flow=		=State Flow and Shared Flow=
	~~Shared~~ flows are		State Flows are hot flows, and are used in the ViewModel to store view state. If the device is rotated we need something to get the original UI state from.

2025-03-18T02:37:37Z

Flow Operators

← Older revision		Revision as of 02:37, 18 March 2025
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	*conflate (need to read up on this)		*conflate (need to read up on this)
	*collectLatest		*collectLatest

	<syntaxhighlight lang="kotlin">		<syntaxhighlight lang="kotlin">
	</syntaxhighlight>		</syntaxhighlight>
			=State Flow and Shared Flow=
			Shared flows are