[Feature] Added Decimal Formatting Capability

shared/domain/src/main/java/com/ivy/domain/features/Features.kt

@@ -7,6 +7,7 @@ interface Features {
     val showTitleSuggestions: BoolFeature
     val showCategorySearchBar: BoolFeature
     val hideTotalBalance: BoolFeature
+    val showDecimalNumber: BoolFeature
 
     val allFeatures: List<BoolFeature>
 }

shared/domain/src/main/java/com/ivy/domain/features/IvyFeatures.kt

@@ -8,7 +8,7 @@ class IvyFeatures @Inject constructor() : Features {
 
     override val sortCategoriesAlphabetically = BoolFeature(
         key = "sort_categories_alphabetically",
-        group = FeatureGroup.Other,
+        group = FeatureGroup.Category,
         name = "Sort Categories Alphabetically",
         description = "Sort income and expenses" +
                 " categories alphabetically"
@@ -52,13 +52,25 @@ class IvyFeatures @Inject constructor() : Features {
         defaultValue = false
     )
 
+    override val showDecimalNumber = BoolFeature(
+        key = "show_decimal_number",
+        group = FeatureGroup.Other,
+        name = "Show Decimal Number",
+        description = "Whether to show the decimal part in amounts",
+        defaultValue = true
+    )
+
     override val allFeatures: List<BoolFeature>
         get() = listOf(
             sortCategoriesAlphabetically,
             compactAccountsMode,
             compactCategoriesMode,
             showTitleSuggestions,
             showCategorySearchBar,
-            hideTotalBalance
+            hideTotalBalance,
+            /* will be uncommented when this functionality
+             * will be available across the application in up-coming PRs
+            showDecimalNumber
+             */
         )
 }

shared/ui/core/src/main/java/com/ivy/ui/FormatMoneyUseCase.kt

@@ -0,0 +1,29 @@
+package com.ivy.ui
+
+import android.content.Context
+import com.ivy.domain.features.Features
+import com.ivy.ui.time.DevicePreferences
+import dagger.hilt.android.qualifiers.ApplicationContext
+import java.text.DecimalFormat
+import java.text.DecimalFormatSymbols
+import javax.inject.Inject
+
+class FormatMoneyUseCase @Inject constructor(
+    private val features: Features,
+    private val devicePreferences: DevicePreferences,
+    @ApplicationContext private val context: Context
+) {
+
+    private val locale = devicePreferences.locale()
+    private val withoutDecimalFormatter = DecimalFormat("###,###", DecimalFormatSymbols(locale))
+    private val withDecimalFormatter = DecimalFormat("###,###.00", DecimalFormatSymbols(locale))
+
+    suspend fun format(value: Double): String {
+        val showDecimalPoint = features.showDecimalNumber.isEnabled(context)
+
+        return when (showDecimalPoint) {
+            true -> withDecimalFormatter.format(value)
+            false -> withoutDecimalFormatter.format(value)
+        }
+    }
+}

shared/ui/core/src/test/java/com/ivy/ui/FormatMoneyUseCaseTest.kt

@@ -0,0 +1,73 @@
+package com.ivy.ui
+
+import android.content.Context
+import com.google.testing.junit.testparameterinjector.TestParameter
+import com.google.testing.junit.testparameterinjector.TestParameterInjector
+import com.ivy.domain.features.Features
+import com.ivy.ui.time.DevicePreferences
+import io.kotest.common.runBlocking
+import io.kotest.matchers.shouldBe
+import io.mockk.coEvery
+import io.mockk.every
+import io.mockk.mockk
+import org.junit.Test
+import org.junit.runner.RunWith
+import java.util.Locale
+
+@RunWith(TestParameterInjector::class)
+class FormatMoneyUseCaseTest {
+
+    private val features = mockk<Features>()
+    private val devicePreferences = mockk<DevicePreferences>()
+
+    enum class MoneyFormatterTestCase(
+        val amount: Double,
+        val showDecimal: Boolean,
+        val locale: Locale,
+        val expectedOutput: String
+    ) {
+        ENG_SHOW_DECIMAL(
+            amount = 1000.12,
+            showDecimal = true,
+            locale = Locale.ENGLISH,
+            expectedOutput = "1,000.12"
+        ),
+        ENG_HIDE_DECIMAL(
+            amount = 1000.12,
+            showDecimal = false,
+            locale = Locale.ENGLISH,
+            expectedOutput = "1,000"
+        ),
+        GERMAN_SHOW_DECIMAL(
+            amount = 1000.12,
+            showDecimal = true,
+            locale = Locale.GERMAN,
+            expectedOutput = "1.000,12"
+        ),
+        GERMAN_HIDE_DECIMAL(
+            amount = 1000.12,
+            showDecimal = false,
+            locale = Locale.GERMAN,
+            expectedOutput = "1.000"
+        ),
+    }
+
+    private lateinit var formatMoneyUseCase: FormatMoneyUseCase
+
+    @Test
+    fun `validate decimal formatting`(
+        @TestParameter testCase: MoneyFormatterTestCase
+    ): Unit = runBlocking {
+        // given
+        val context = mockk<Context>()
+        every { features.showDecimalNumber } returns mockk { coEvery { isEnabled(any()) } returns testCase.showDecimal }
+        every { devicePreferences.locale() } returns testCase.locale
+        formatMoneyUseCase = FormatMoneyUseCase(features, devicePreferences, context)
+
+        // when
+        val result = formatMoneyUseCase.format(value = testCase.amount)
+
+        // then
+        result shouldBe testCase.expectedOutput
+    }
+}