Add validation for input arguments

src/nativeMain/kotlin/Main.kt

@@ -5,13 +5,21 @@ import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.onEach
 import logger.Logger
 import logger.context
+import platform.posix.exit
 import userInput.Arguments
 import userInput.Keymap
 import userInput.Keymap.Actions
 
 @OptIn(ExperimentalCoroutinesApi::class, DelicateCoroutinesApi::class)
 fun main(args: Array<String>) {
- Arguments.validate(args)
+ val appModule = AppModule()
+
+ try {
+ appModule.arguments.validate(args)
+ } catch (e: Arguments.ValidationException) {
+ println(e.message)
+ exit(1)
+ }
 
  val ui = newSingleThreadContext("UI")
 
@@ -24,8 +32,6 @@ fun main(args: Array<String>) {
  //he key takeaway is that if you call launch on a custom CoroutineScope, any CoroutineExceptionHandler provided
  // directly to the CoroutineScope constructor or to launch will be executed when an exception is thrown within the launched coroutine.
  val appJob = CoroutineScope(ui).launch(handler) {
- val appModule = AppModule()
-
  with(appModule) {
  Logger.set(fileLogger)
 

src/nativeMain/kotlin/di/AppModule.kt

@@ -5,7 +5,7 @@ import BuildConfig
 import FileLogger
 import InternalAppState
 import di.DogcatModule.dogcatModule
-import kotlinx.coroutines.CloseableCoroutineDispatcher
+import kotlinx.cli.ArgParser
 import logger.CanLog
 import logger.NoOpLogger
 import org.kodein.di.DI
@@ -14,6 +14,7 @@ import org.kodein.di.instance
 import ui.AppPresenter
 import ui.logLines.LogLinesPresenter
 import ui.status.StatusPresenter
+import userInput.Arguments
 import userInput.DefaultInput
 import userInput.Input
 
@@ -27,6 +28,7 @@ class AppModule {
  NoOpLogger()
  }
  }
+ bindSingleton<Arguments> { Arguments(ArgParser("dogcat")) }
  bindSingleton<AppState> { InternalAppState() }
  bindSingleton<Input> { DefaultInput(instance()) }
  bindSingleton<AppPresenter> {
@@ -35,6 +37,7 @@ class AppModule {
  instance(),
  instance(),
  instance(),
+ instance(),
  instance()
  )
  }
@@ -47,6 +50,7 @@ class AppModule {
  }
  bindSingleton<LogLinesPresenter> {
  LogLinesPresenter(
+ instance(),
  instance(),
  instance(),
  instance()
@@ -61,6 +65,8 @@ class AppModule {
 
  val fileLogger: CanLog by serviceLocator.instance()
 
+ val arguments: Arguments by serviceLocator.instance()
+
  val input: Input by serviceLocator.instance()
 
  val appPresenter: AppPresenter by serviceLocator.instance()

src/nativeMain/kotlin/ui/AppPresenter.kt

@@ -10,11 +10,13 @@ import dogcat.state.PublicState
 import dogcat.state.PublicState.Active
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.ExperimentalCoroutinesApi
-import kotlinx.coroutines.flow.*
+import kotlinx.coroutines.flow.distinctUntilChanged
+import kotlinx.coroutines.flow.filter
+import kotlinx.coroutines.flow.filterIsInstance
+import kotlinx.coroutines.flow.flatMapLatest
 import kotlinx.coroutines.launch
 import logger.Logger
 import logger.context
-import ui.Strings.INPUT_FILTER_PREFIX
 import ui.logLines.LogLinesPresenter
 import ui.status.StatusPresenter
 import userInput.Arguments
@@ -25,6 +27,7 @@ import kotlin.coroutines.coroutineContext
 
 class AppPresenter(
  private val dogcat: Dogcat,
+ private val arguments: Arguments,
  private val appState: AppState,
  private val input: Input,
  private val logLinesPresenter: LogLinesPresenter,
@@ -35,8 +38,8 @@ class AppPresenter(
 
  override suspend fun start() {
  when {
- Arguments.packageName != null -> dogcat(PickAppPackage(Arguments.packageName!!))
- Arguments.current == true -> dogcat(PickForegroundApp)
+ arguments.packageName != null -> dogcat(PickAppPackage(arguments.packageName!!))
+ arguments.current == true -> dogcat(PickForegroundApp)
  else -> dogcat(PickAllApps)
  }
 

src/nativeMain/kotlin/ui/logLines/LogLinesPresenter.kt

@@ -19,6 +19,7 @@ import kotlin.coroutines.coroutineContext
 
 class LogLinesPresenter(
  private val dogcat: Dogcat,
+ private val arguments: Arguments,
  private val appState: AppState,
  private val input: Input,
 ) : HasLifecycle {
@@ -55,7 +56,7 @@ class LogLinesPresenter(
  .collect {
  view.state = view.state.copy(
  autoscroll = it.autoscroll,
- showLineNumbers = Arguments.lineNumbers ?: false,
+ showLineNumbers = arguments.lineNumbers ?: false,
  isCursorHeld = it.isCursorHeld,
  cursorReturnLocation = it.inputFilterLocation
  )

src/nativeMain/kotlin/userInput/Arguments.kt

@@ -4,18 +4,34 @@ import kotlinx.cli.ArgParser
 import kotlinx.cli.ArgType
 import kotlinx.cli.optional
 
-object Arguments {
+class Arguments(private val parser: ArgParser) {
 
- private val parser = ArgParser("dogcat")
+ class ValidationException(override val message: String) : RuntimeException(message)
 
- val packageName by parser.argument(ArgType.String, "package name", "description for p n").optional()
- val current by parser.option(ArgType.Boolean, shortName = "c", description = "Filter by currently running program")
- val lineNumbers by parser.option(ArgType.Boolean, shortName = "ln", description = "Show line numbers")
+ val packageName by parser.argument(
+ ArgType.String,
+ "package name",
+ "Show logs for a particular application specified by this package name. " +
+ "Example: 'com.google.android.apps.messaging'."
+ ).optional()
+
+ val current by parser.option(
+ ArgType.Boolean,
+ shortName = "c",
+ description = "Show logs for an application currently running in foreground"
+ )
+
+ val lineNumbers by parser.option(
+ ArgType.Boolean,
+ shortName = "ln",
+ description = "Show line numbers for log lines, embedded into message body"
+ )
 
  fun validate(args: Array<String>) {
  parser.parse(args)
  if (packageName != null && current != null) {
- //can't have both at the same time
+ throw ValidationException("'Package name' and '--current' arguments are mutually exclusive and " +
+ "can't be used at the same time.")
  }
  }
 }