ci: add ktlint formatter and CI checks for code style tools

.editorconfig

@@ -0,0 +1,23 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.{kt,kts}]
+indent_size = 4
+indent_style = space
+ktlint_code_style = intellij_idea
+ktlint_function_naming_ignore_when_annotated_with = Composable
+
+[shared/src/*Main/kotlin/org/mpc/core/*.kt]
+# Factory files are organized by function and use KMP target suffixes, so their
+# names intentionally do not mirror one declaration in PascalCase.
+ktlint_standard_filename = disabled
+
+[shared/src/commonMain/kotlin/org/mpc/presentation/icon/*.kt]
+# These are generated-style Material icon definitions whose private cache names
+# intentionally follow the upstream icon source rather than property conventions.
+ktlint_standard_backing-property-naming = disabled

.github/workflows/lint.yml

@@ -0,0 +1,65 @@
+name: Lint
+
+on:
+  pull_request:
+  push:
+    branches:
+      - dev
+      - main
+
+permissions:
+  contents: read
+
+concurrency:
+  group: lint-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  kotlin:
+    name: Detekt and ktlint
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v7
+        with:
+          persist-credentials: false
+
+      # required for gradle 9.5.0 and android gradle plugin 9.3.0
+      - name: Set up Java
+        uses: actions/setup-java@v5
+        with:
+          distribution: temurin
+          java-version: "17"
+
+      - name: Set up Gradle
+        uses: gradle/actions/setup-gradle@v6
+        with:
+          cache-provider: basic
+
+      - name: Run Detekt and ktlint
+        run: >-
+          ./gradlew
+          ktlintCheck
+          :shared:detektMainAndroid
+          :shared:detektHostTestAndroid
+          :androidApp:detektDebug
+          --no-daemon
+
+  swift:
+    name: SwiftLint
+    runs-on: macos-latest
+    timeout-minutes: 10
+
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v7
+        with:
+          persist-credentials: false
+
+      - name: Install SwiftLint
+        run: brew install swiftlint
+
+      - name: Run SwiftLint
+        run: swiftlint lint --config .swiftlint.yml --no-cache iosApp/iosApp

androidApp/build.gradle.kts

@@ -5,6 +5,7 @@ plugins {
     alias(libs.plugins.composeMultiplatform)
     alias(libs.plugins.composeCompiler)
     alias(libs.plugins.detekt)
+    alias(libs.plugins.ktlint)
     alias(libs.plugins.testBalloon)
 }
 
@@ -72,3 +73,12 @@ detekt {
     config.setFrom(rootProject.file("config/detekt/detekt.yml"))
     buildUponDefaultConfig = true
 }
+
+ktlint {
+    version.set(libs.versions.ktlint)
+    filter {
+        exclude {
+            "/build/generated/" in it.file.invariantSeparatorsPath
+        }
+    }
+}

androidApp/src/main/kotlin/org/mpc/AndroidShell.kt

@@ -27,9 +27,9 @@ fun AndroidAppShell(appGraph: AppGraph) {
             ) { paddingValues ->
                 Box(
                     modifier =
-                        Modifier
-                            .fillMaxSize()
-                            .padding(paddingValues),
+                    Modifier
+                        .fillMaxSize()
+                        .padding(paddingValues),
                 ) {
                     CourseSelectionSearchScreen(modifier = Modifier.fillMaxSize())
                 }

androidApp/src/main/kotlin/org/mpc/presentation/CourseSelectionSearchScreen.kt

@@ -64,21 +64,21 @@ fun CourseSelectionSearchScreen(
     ) {
         SearchBar(
             modifier =
-                Modifier
-                    .fillMaxWidth()
-                    .padding(
-                        horizontal = 16.dp,
-                        vertical = 8.dp,
-                    ),
+            Modifier
+                .fillMaxWidth()
+                .padding(
+                    horizontal = 16.dp,
+                    vertical = 8.dp,
+                ),
             state = searchBarState,
             inputField = inputField,
         )
 
         CourseSearchResultView(
             modifier =
-                Modifier
-                    .fillMaxWidth()
-                    .weight(1f),
+            Modifier
+                .fillMaxWidth()
+                .weight(1f),
             uiState = searchUiState.result,
             selectedCourseSerialNumbers = selectedCourseSerialNumbers,
             onToggleCourse = planViewModel::toggleCourse,
@@ -91,9 +91,9 @@ fun CourseSelectionSearchScreen(
     ) {
         CourseSearchResultView(
             modifier =
-                Modifier
-                    .fillMaxWidth()
-                    .weight(1f),
+            Modifier
+                .fillMaxWidth()
+                .weight(1f),
             uiState = searchUiState.result,
             selectedCourseSerialNumbers = selectedCourseSerialNumbers,
             onToggleCourse = planViewModel::toggleCourse,

build.gradle.kts

@@ -14,9 +14,20 @@ plugins {
     alias(libs.plugins.ksp) apply false
     alias(libs.plugins.androidx.room) apply false
     alias(libs.plugins.detekt) apply false
+    alias(libs.plugins.ktlint) apply false
     alias(libs.plugins.testBalloon) apply false
 }
 
+val ktlintCheck by tasks.registering {
+    group = "verification"
+    description = "Runs ktlint checks for all Kotlin modules."
+
+    dependsOn(
+        ":shared:ktlintCheck",
+        ":androidApp:ktlintCheck",
+    )
+}
+
 val swiftLint by tasks.registering(Exec::class) {
     group = "verification"
     description = "Runs SwiftLint against the iOS application."
@@ -55,6 +66,7 @@ tasks.register("check") {
         ":androidApp:check",
         ":androidApp:detektDebug",
         ":androidApp:lintDebug",
+        ktlintCheck,
         swiftLint,
     )
 }

gradle/libs.versions.toml

@@ -26,6 +26,8 @@ sqlite = "2.7.0"
 ksp = "2.3.10"
 
 detekt = "2.0.0-alpha.5"
+ktlint = "1.8.0"
+ktlintPlugin = "14.2.0"
 
 testBalloon = "1.0.1-K2.4.0"
 
@@ -86,3 +88,4 @@ testBalloon = { id = "de.infix.testBalloon", version.ref = "testBalloon" }
 
 ksp = { id = "com.google.devtools.ksp", version.ref = "ksp" }
 detekt = { id = "dev.detekt", version.ref = "detekt" }
+ktlint = { id = "org.jlleitschuh.gradle.ktlint", version.ref = "ktlintPlugin" }

shared/build.gradle.kts

@@ -10,6 +10,7 @@ plugins {
     alias(libs.plugins.ksp)
     alias(libs.plugins.androidx.room)
     alias(libs.plugins.detekt)
+    alias(libs.plugins.ktlint)
     alias(libs.plugins.testBalloon)
 }
 
@@ -106,3 +107,12 @@ detekt {
     config.setFrom(rootProject.file("config/detekt/detekt.yml"))
     buildUponDefaultConfig = true
 }
+
+ktlint {
+    version.set(libs.versions.ktlint)
+    filter {
+        exclude {
+            "/build/generated/" in it.file.invariantSeparatorsPath
+        }
+    }
+}

shared/src/androidMain/kotlin/org/mpc/core/dataStoreFactory.android.kt

@@ -8,13 +8,12 @@ import androidx.datastore.preferences.core.PreferencesSerializer
 import okio.FileSystem
 import okio.Path.Companion.toOkioPath
 
-fun createDataStore(context: Context): Storage<Preferences> =
-    OkioStorage(
-        fileSystem = FileSystem.SYSTEM,
-        serializer = PreferencesSerializer,
-        producePath = {
-            context.filesDir
-                .resolve(DATA_STORE_FILE_NAME)
-                .toOkioPath()
-        },
-    )
+fun createDataStore(context: Context): Storage<Preferences> = OkioStorage(
+    fileSystem = FileSystem.SYSTEM,
+    serializer = PreferencesSerializer,
+    producePath = {
+        context.filesDir
+            .resolve(DATA_STORE_FILE_NAME)
+            .toOkioPath()
+    },
+)

shared/src/commonMain/kotlin/org/mpc/core/dataBaseBuilder.kt

@@ -8,10 +8,9 @@ import org.mpc.data.local.database.AppDatabase
 
 // This is the database composition root, before the Metro graph exists.
 @Suppress("InjectDispatcher")
-fun createDatabase(builder: RoomDatabase.Builder<AppDatabase>): AppDatabase =
-    builder
-        .setDriver(BundledSQLiteDriver())
-        .setQueryCoroutineContext(Dispatchers.IO)
-        .build()
+fun createDatabase(builder: RoomDatabase.Builder<AppDatabase>): AppDatabase = builder
+    .setDriver(BundledSQLiteDriver())
+    .setQueryCoroutineContext(Dispatchers.IO)
+    .build()
 
 internal const val DATABASE_NAME = "mpc.db"

shared/src/commonMain/kotlin/org/mpc/core/httpClientFactory.kt

@@ -13,8 +13,7 @@ import kotlinx.serialization.json.Json
 import kotlinx.serialization.json.JsonNamingStrategy
 
 @OptIn(ExperimentalSerializationApi::class)
-fun createHttpClient(): HttpClient =
-    // TODO: maybe assign platform specific engine via expect/actual could be an option
+fun createHttpClient(): HttpClient = // TODO: maybe assign platform specific engine via expect/actual could be an option
     HttpClient {
         install(Logging) {
             logger =

shared/src/commonMain/kotlin/org/mpc/data/local/dao/CourseCatalogDao.kt

@@ -34,11 +34,13 @@ interface CourseCatalogDao {
     @Query("DELETE FROM course_catalog WHERE semester = :semester")
     suspend fun deleteCatalog(semester: String)
 
-    @Query("""
+    @Query(
+        """
         DELETE FROM course
         WHERE semester = :semester
           AND serialNo IN (:serialNos)
-    """)
+    """,
+    )
     suspend fun deleteCourses(semester: String, serialNos: List<String>)
 
     @Query("SELECT * FROM course WHERE semester = :semester ORDER BY serialNo")
@@ -67,7 +69,7 @@ interface CourseCatalogDao {
         if (removedCourseSerialNos.isNotEmpty()) {
             deleteCourses(
                 semester = entities.catalog.semester,
-                serialNos = removedCourseSerialNos
+                serialNos = removedCourseSerialNos,
             )
         }
 

shared/src/commonMain/kotlin/org/mpc/data/local/entities/LocalCatalogEntities.kt

@@ -44,10 +44,10 @@ internal fun CourseResult.toLocalCatalogEntities(): LocalCatalogEntities {
 
     return LocalCatalogEntities(
         catalog =
-            CourseCatalogEntity(
-                semester = semester,
-                lastUpdatedEpochMillis = lastUpdated.toEpochMilliseconds(),
-            ),
+        CourseCatalogEntity(
+            semester = semester,
+            lastUpdatedEpochMillis = lastUpdated.toEpochMilliseconds(),
+        ),
         courses = courseEntities,
         teachers = teacherEntities,
         courseTimes = timeEntities,
@@ -82,26 +82,26 @@ internal fun LocalCatalogEntities.toDomain(): CourseResult {
         lastUpdated = Instant.fromEpochMilliseconds(catalog.lastUpdatedEpochMillis),
         semester = catalog.semester,
         courses =
-            courses.map { course ->
-                val key =
-                    CourseKey(
-                        semester = course.semester,
-                        serialNo = course.serialNo,
-                    )
-
-                course.toDomain(
-                    teachers = teachersByCourse[key].orEmpty().map { it.teacherName },
-                    classTimes =
-                        timesByCourse[key]
-                            .orEmpty()
-                            .mapNotNull { it.toDomainOrNull() }
-                            .sortedWith(
-                                compareBy(
-                                    { it.day.order },
-                                    { it.period.order },
-                                ),
-                            ),
+        courses.map { course ->
+            val key =
+                CourseKey(
+                    semester = course.semester,
+                    serialNo = course.serialNo,
                 )
-            },
+
+            course.toDomain(
+                teachers = teachersByCourse[key].orEmpty().map { it.teacherName },
+                classTimes =
+                timesByCourse[key]
+                    .orEmpty()
+                    .mapNotNull { it.toDomainOrNull() }
+                    .sortedWith(
+                        compareBy(
+                            { it.day.order },
+                            { it.period.order },
+                        ),
+                    ),
+            )
+        },
     )
 }