diff --git a/app/src/test/java/com/kickstarter/viewmodels/RewardsSelectionViewModelTest.kt b/app/src/test/java/com/kickstarter/viewmodels/RewardsSelectionViewModelTest.kt
new file mode 100644
index 0000000000..d7aba3f192
--- /dev/null
+++ b/app/src/test/java/com/kickstarter/viewmodels/RewardsSelectionViewModelTest.kt
@@ -0,0 +1,595 @@
+package com.kickstarter.viewmodels
+
+import com.kickstarter.KSRobolectricTestCase
+import com.kickstarter.models.Backing
+import com.kickstarter.models.Project
+import com.kickstarter.models.Reward
+import com.kickstarter.ui.data.ProjectData
+import com.kickstarter.viewmodels.projectpage.FlowUIState
+import com.kickstarter.viewmodels.projectpage.RewardSelectionUIState
+import com.kickstarter.viewmodels.projectpage.RewardsSelectionViewModel
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.flow.toList
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.test.UnconfinedTestDispatcher
+import kotlinx.coroutines.test.runTest
+import org.junit.Test
+
+class RewardsSelectionViewModelTest : KSRobolectricTestCase() {
+
+    private lateinit var viewModel: RewardsSelectionViewModel
+
+    private fun createViewModel() {
+        viewModel =
+            RewardsSelectionViewModel.Factory().create(RewardsSelectionViewModel::class.java)
+    }
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Test
+    fun test_providing_project_should_initialize_UIState() = runTest {
+        createViewModel()
+
+        val testRewards = (0..5).map { Reward.builder().title("$it").id(it.toLong()).build() }
+        val testBacking =
+            Backing.builder().reward(testRewards[2]).rewardId(testRewards[2].id()).build()
+        val testProject = Project.builder().rewards(testRewards).backing(testBacking).build()
+        val testProjectData = ProjectData.builder().project(testProject).build()
+
+        viewModel.provideProjectData(testProjectData)
+
+        val state = mutableListOf<RewardSelectionUIState>()
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            viewModel.rewardSelectionUIState.toList(state)
+        }
+
+        // 1 from initialization, 1 from providing project data
+        assert(state.size == 2)
+        assertEquals(
+            state.last(),
+            RewardSelectionUIState(
+                rewardList = testRewards,
+                initialRewardIndex = 2,
+                project = testProjectData,
+                showAlertDialog = false
+            )
+        )
+    }
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Test
+    fun test_selecting_reward_with_addOns_no_previous_backing() = runTest {
+        createViewModel()
+
+        val testRewards =
+            (0..5).map { Reward.builder().title("$it").id(it.toLong()).hasAddons(true).build() }
+        val testProject = Project.builder().rewards(testRewards).build()
+        val testProjectData = ProjectData.builder().project(testProject).build()
+
+        viewModel.provideProjectData(testProjectData)
+
+        val uiState = mutableListOf<RewardSelectionUIState>()
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            viewModel.rewardSelectionUIState.toList(uiState)
+        }
+
+        val flowState = mutableListOf<FlowUIState>()
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            viewModel.flowUIRequest.toList(flowState)
+        }
+
+        assert(uiState.size == 2)
+        assert(flowState.size == 0)
+        assertEquals(
+            uiState.last(),
+            RewardSelectionUIState(
+                rewardList = testRewards,
+                initialRewardIndex = 0,
+                project = testProjectData,
+                showAlertDialog = false
+            )
+        )
+
+        viewModel.onUserRewardSelection(testRewards[2])
+
+        assert(uiState.size == 2)
+        assert(flowState.size == 1)
+        assertEquals(
+            flowState.last(),
+            FlowUIState(currentPage = 1, expanded = true)
+        )
+    }
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Test
+    fun test_selecting_reward_no_addOns_no_previous_backing() = runTest {
+        createViewModel()
+
+        val testRewards =
+            (0..5).map { Reward.builder().title("$it").id(it.toLong()).hasAddons(false).build() }
+        val testProject = Project.builder().rewards(testRewards).build()
+        val testProjectData = ProjectData.builder().project(testProject).build()
+
+        viewModel.provideProjectData(testProjectData)
+
+        val uiState = mutableListOf<RewardSelectionUIState>()
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            viewModel.rewardSelectionUIState.toList(uiState)
+        }
+
+        val flowState = mutableListOf<FlowUIState>()
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            viewModel.flowUIRequest.toList(flowState)
+        }
+
+        assert(uiState.size == 2)
+        assert(flowState.size == 0)
+        assertEquals(
+            uiState.last(),
+            RewardSelectionUIState(
+                rewardList = testRewards,
+                initialRewardIndex = 0,
+                project = testProjectData,
+                showAlertDialog = false
+            )
+        )
+
+        viewModel.onUserRewardSelection(testRewards[2])
+
+        assert(uiState.size == 2)
+        assert(flowState.size == 1)
+        assertEquals(
+            flowState.last(),
+            FlowUIState(currentPage = 2, expanded = true)
+        )
+    }
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Test
+    fun test_selecting_reward_with_addOns_previous_backing_same_selection() = runTest {
+        createViewModel()
+
+        val testRewards =
+            (0..5).map { Reward.builder().title("$it").id(it.toLong()).hasAddons(true).build() }
+        val testBacking =
+            Backing.builder().reward(testRewards[2]).rewardId(testRewards[2].id()).build()
+        val testProject =
+            Project.builder().rewards(testRewards).backing(testBacking).isBacking(true).build()
+        val testProjectData =
+            ProjectData.builder().project(testProject).backing(testBacking).build()
+
+        viewModel.provideProjectData(testProjectData)
+
+        val uiState = mutableListOf<RewardSelectionUIState>()
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            viewModel.rewardSelectionUIState.toList(uiState)
+        }
+
+        val flowState = mutableListOf<FlowUIState>()
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            viewModel.flowUIRequest.toList(flowState)
+        }
+
+        assert(uiState.size == 2)
+        assert(flowState.size == 0)
+        assertEquals(
+            uiState.last(),
+            RewardSelectionUIState(
+                rewardList = testRewards,
+                initialRewardIndex = 2,
+                project = testProjectData,
+                showAlertDialog = false
+            )
+        )
+
+        viewModel.onUserRewardSelection(testRewards[2])
+
+        assert(uiState.size == 2)
+        assert(flowState.size == 1)
+        assertEquals(
+            flowState.last(),
+            FlowUIState(currentPage = 1, expanded = true)
+        )
+    }
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Test
+    fun test_selecting_reward_with_addOns_previous_backing_different_selection() = runTest {
+        createViewModel()
+
+        val testRewards =
+            (0..5).map { Reward.builder().title("$it").id(it.toLong()).hasAddons(true).build() }
+        val testBacking =
+            Backing.builder().reward(testRewards[3]).rewardId(testRewards[3].id()).build()
+        val testProject =
+            Project.builder().rewards(testRewards).backing(testBacking).isBacking(true).build()
+        val testProjectData =
+            ProjectData.builder().project(testProject).backing(testBacking).build()
+
+        viewModel.provideProjectData(testProjectData)
+
+        val uiState = mutableListOf<RewardSelectionUIState>()
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            viewModel.rewardSelectionUIState.toList(uiState)
+        }
+
+        val flowState = mutableListOf<FlowUIState>()
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            viewModel.flowUIRequest.toList(flowState)
+        }
+
+        assert(uiState.size == 2)
+        assert(flowState.size == 0)
+        assertEquals(
+            uiState.last(),
+            RewardSelectionUIState(
+                rewardList = testRewards,
+                initialRewardIndex = 3,
+                project = testProjectData,
+                showAlertDialog = false
+            )
+        )
+
+        viewModel.onUserRewardSelection(testRewards[2])
+
+        assert(uiState.size == 2)
+        assert(flowState.size == 1)
+        assertEquals(
+            flowState.last(),
+            FlowUIState(currentPage = 1, expanded = true)
+        )
+    }
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Test
+    fun test_selecting_reward_with_no_addOns_previous_backing_has_addOns() = runTest {
+        createViewModel()
+
+        val testRewards =
+            (0..5).map { Reward.builder().title("$it").id(it.toLong()).hasAddons(it != 2).build() }
+        val testBacking =
+            Backing.builder().reward(testRewards[3]).rewardId(testRewards[3].id()).build()
+        val testProject =
+            Project.builder().rewards(testRewards).backing(testBacking).isBacking(true).build()
+        val testProjectData =
+            ProjectData.builder().project(testProject).backing(testBacking).build()
+
+        viewModel.provideProjectData(testProjectData)
+
+        val uiState = mutableListOf<RewardSelectionUIState>()
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            viewModel.rewardSelectionUIState.toList(uiState)
+        }
+
+        val flowState = mutableListOf<FlowUIState>()
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            viewModel.flowUIRequest.toList(flowState)
+        }
+
+        assert(uiState.size == 2)
+        assert(flowState.size == 0)
+        assertEquals(
+            uiState.last(),
+            RewardSelectionUIState(
+                rewardList = testRewards,
+                initialRewardIndex = 3,
+                project = testProjectData,
+                showAlertDialog = false
+            )
+        )
+
+        viewModel.onUserRewardSelection(testRewards[2])
+
+        assert(uiState.size == 3)
+        assert(flowState.size == 0)
+        assertEquals(
+            uiState.last(),
+            RewardSelectionUIState(
+                rewardList = testRewards,
+                initialRewardIndex = 0,
+                project = testProjectData,
+                showAlertDialog = true
+            )
+        )
+    }
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Test
+    fun test_selecting_reward_with_no_addOns_previous_backing_no_addOns() = runTest {
+        createViewModel()
+
+        val testRewards =
+            (0..5).map { Reward.builder().title("$it").id(it.toLong()).hasAddons(false).build() }
+        val testBacking =
+            Backing.builder().reward(testRewards[3]).rewardId(testRewards[3].id()).build()
+        val testProject =
+            Project.builder().rewards(testRewards).backing(testBacking).isBacking(true).build()
+        val testProjectData =
+            ProjectData.builder().project(testProject).backing(testBacking).build()
+
+        viewModel.provideProjectData(testProjectData)
+
+        val uiState = mutableListOf<RewardSelectionUIState>()
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            viewModel.rewardSelectionUIState.toList(uiState)
+        }
+
+        val flowState = mutableListOf<FlowUIState>()
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            viewModel.flowUIRequest.toList(flowState)
+        }
+
+        assert(uiState.size == 2)
+        assert(flowState.size == 0)
+        assertEquals(
+            uiState.last(),
+            RewardSelectionUIState(
+                rewardList = testRewards,
+                initialRewardIndex = 3,
+                project = testProjectData,
+                showAlertDialog = false
+            )
+        )
+
+        viewModel.onUserRewardSelection(testRewards[2])
+
+        assert(uiState.size == 2)
+        assert(flowState.size == 1)
+        assertEquals(
+            flowState.last(),
+            FlowUIState(currentPage = 2, expanded = true)
+        )
+    }
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Test
+    fun test_selecting_reward_with_addOns_previous_backing_has_addOns_different_shipping() =
+        runTest {
+            createViewModel()
+
+            val testRewards = (0..5).map {
+                Reward.builder().title("$it").id(it.toLong()).hasAddons(true).shippingType("$it")
+                    .build()
+            }
+            val testBacking =
+                Backing.builder().reward(testRewards[3]).rewardId(testRewards[3].id()).build()
+            val testProject =
+                Project.builder().rewards(testRewards).backing(testBacking).isBacking(true).build()
+            val testProjectData =
+                ProjectData.builder().project(testProject).backing(testBacking).build()
+
+            viewModel.provideProjectData(testProjectData)
+
+            val uiState = mutableListOf<RewardSelectionUIState>()
+            backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+                viewModel.rewardSelectionUIState.toList(uiState)
+            }
+
+            val flowState = mutableListOf<FlowUIState>()
+            backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+                viewModel.flowUIRequest.toList(flowState)
+            }
+
+            assert(uiState.size == 2)
+            assert(flowState.size == 0)
+            assertEquals(
+                uiState.last(),
+                RewardSelectionUIState(
+                    rewardList = testRewards,
+                    initialRewardIndex = 3,
+                    project = testProjectData,
+                    showAlertDialog = false
+                )
+            )
+
+            viewModel.onUserRewardSelection(testRewards[2])
+
+            assert(uiState.size == 3)
+            assert(flowState.size == 0)
+            assertEquals(
+                uiState.last(),
+                RewardSelectionUIState(
+                    rewardList = testRewards,
+                    initialRewardIndex = 0,
+                    project = testProjectData,
+                    showAlertDialog = true
+                )
+            )
+        }
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Test
+    fun test_alert_dialog_positive_option_reward_has_add_ons() = runTest {
+        createViewModel()
+
+        val testRewards = (0..5).map {
+            Reward.builder().title("$it").id(it.toLong()).hasAddons(true).shippingType("$it")
+                .build()
+        }
+        val testBacking =
+            Backing.builder().reward(testRewards[3]).rewardId(testRewards[3].id()).build()
+        val testProject =
+            Project.builder().rewards(testRewards).backing(testBacking).isBacking(true).build()
+        val testProjectData =
+            ProjectData.builder().project(testProject).backing(testBacking).build()
+
+        viewModel.provideProjectData(testProjectData)
+
+        val uiState = mutableListOf<RewardSelectionUIState>()
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            viewModel.rewardSelectionUIState.toList(uiState)
+        }
+
+        val flowState = mutableListOf<FlowUIState>()
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            viewModel.flowUIRequest.toList(flowState)
+        }
+
+        assert(uiState.size == 2)
+        assert(flowState.size == 0)
+        assertEquals(
+            uiState.last(),
+            RewardSelectionUIState(
+                rewardList = testRewards,
+                initialRewardIndex = 3,
+                project = testProjectData,
+                showAlertDialog = false
+            )
+        )
+
+        viewModel.onUserRewardSelection(testRewards[2])
+
+        assert(uiState.size == 3)
+        assert(flowState.size == 0)
+        assertEquals(
+            uiState.last(),
+            RewardSelectionUIState(
+                rewardList = testRewards,
+                initialRewardIndex = 0,
+                project = testProjectData,
+                showAlertDialog = true
+            )
+        )
+
+        viewModel.onRewardCarouselAlertClicked(wasPositive = true)
+
+        assert(uiState.size == 4)
+        assert(flowState.size == 1)
+        assertEquals(
+            flowState.last(),
+            FlowUIState(currentPage = 1, expanded = true)
+        )
+    }
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Test
+    fun test_alert_dialog_positive_option_reward_no_add_ons() = runTest {
+        createViewModel()
+
+        val testRewards = (0..5).map {
+            Reward.builder().title("$it").id(it.toLong()).hasAddons(it != 2).shippingType("$it")
+                .build()
+        }
+        val testBacking =
+            Backing.builder().reward(testRewards[3]).rewardId(testRewards[3].id()).build()
+        val testProject =
+            Project.builder().rewards(testRewards).backing(testBacking).isBacking(true).build()
+        val testProjectData =
+            ProjectData.builder().project(testProject).backing(testBacking).build()
+
+        viewModel.provideProjectData(testProjectData)
+
+        val uiState = mutableListOf<RewardSelectionUIState>()
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            viewModel.rewardSelectionUIState.toList(uiState)
+        }
+
+        val flowState = mutableListOf<FlowUIState>()
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            viewModel.flowUIRequest.toList(flowState)
+        }
+
+        assert(uiState.size == 2)
+        assert(flowState.size == 0)
+        assertEquals(
+            uiState.last(),
+            RewardSelectionUIState(
+                rewardList = testRewards,
+                initialRewardIndex = 3,
+                project = testProjectData,
+                showAlertDialog = false
+            )
+        )
+
+        viewModel.onUserRewardSelection(testRewards[2])
+
+        assert(uiState.size == 3)
+        assert(flowState.size == 0)
+        assertEquals(
+            uiState.last(),
+            RewardSelectionUIState(
+                rewardList = testRewards,
+                initialRewardIndex = 0,
+                project = testProjectData,
+                showAlertDialog = true
+            )
+        )
+
+        viewModel.onRewardCarouselAlertClicked(wasPositive = true)
+
+        assert(uiState.size == 4)
+        assert(flowState.size == 1)
+        assertEquals(
+            flowState.last(),
+            FlowUIState(currentPage = 2, expanded = true)
+        )
+    }
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Test
+    fun test_alert_dialog_negative_option_reward_no_add_ons() = runTest {
+        createViewModel()
+
+        val testRewards = (0..5).map {
+            Reward.builder().title("$it").id(it.toLong()).hasAddons(it != 2).shippingType("$it")
+                .build()
+        }
+        val testBacking =
+            Backing.builder().reward(testRewards[3]).rewardId(testRewards[3].id()).build()
+        val testProject =
+            Project.builder().rewards(testRewards).backing(testBacking).isBacking(true).build()
+        val testProjectData =
+            ProjectData.builder().project(testProject).backing(testBacking).build()
+
+        viewModel.provideProjectData(testProjectData)
+
+        val uiState = mutableListOf<RewardSelectionUIState>()
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            viewModel.rewardSelectionUIState.toList(uiState)
+        }
+
+        val flowState = mutableListOf<FlowUIState>()
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            viewModel.flowUIRequest.toList(flowState)
+        }
+
+        assert(uiState.size == 2)
+        assert(flowState.size == 0)
+        assertEquals(
+            uiState.last(),
+            RewardSelectionUIState(
+                rewardList = testRewards,
+                initialRewardIndex = 3,
+                project = testProjectData,
+                showAlertDialog = false
+            )
+        )
+
+        viewModel.onUserRewardSelection(testRewards[2])
+
+        assert(uiState.size == 3)
+        assert(flowState.size == 0)
+        assertEquals(
+            uiState.last(),
+            RewardSelectionUIState(
+                rewardList = testRewards,
+                initialRewardIndex = 0,
+                project = testProjectData,
+                showAlertDialog = true
+            )
+        )
+
+        viewModel.onRewardCarouselAlertClicked(wasPositive = false)
+
+        assert(uiState.size == 4)
+        assert(flowState.size == 0)
+        assertEquals(
+            uiState.last(),
+            RewardSelectionUIState(
+                rewardList = testRewards,
+                initialRewardIndex = 0,
+                project = testProjectData,
+                showAlertDialog = false
+            )
+        )
+    }
+}