Diff formatting shows weird whitespace characters on Windows 10 (� and ╖ instead of ·)

まず、Windows 10 上で示されている Spotless 5.5.1 構成を使って gradlew spotlessCheck を再現し、そのコンソール出力を macOS と比較します。Kotlin が使用する差分フォーマットのエントリーポイントを追跡します。完了条件は、Windows Command Prompt と IDE コンソールで空白マーカーが一貫して · として表示されることです。

Summary of problem

When outputting the details of what lines have format violations, the · characters representing whitespace are not rendering correctly in the Command Prompt, Android Studio & Intellij's console output on Windows 10. I tried the same project with the same IDEs and Gradle files on Mac OS Catalina and don't see the issue.

I use defaults fonts on Windows and in the IDEs. I tried other monospaced fonts and character encoding thinking it's something on my end. Didn't seem to have any effect. I'm suspecting something in the library is possibly using an encoding that isn't translating back to UTF-8 correctly.

Android Studio & Intellij's output (Windows 10)

Execution failed for task ':app:spotlessKotlinCheck'.
> The following files had format violations:
app\src\main\java\com\corwinjv\postmodernandroid\common\di\NetworkModule.kt
          @@ -6,15 +6,14 @@
           import�dagger.Provides
           import�dagger.hilt.InstallIn
           import�dagger.hilt.android.components.ApplicationComponent
          +import�javax.inject.Singleton
           import�okhttp3.OkHttpClient
           import�retrofit2.Retrofit
           import�retrofit2.converter.gson.GsonConverterFactory
          -import�javax.inject.Singleton
           @InstallIn(ApplicationComponent::class)
           @Module
          -class�NetworkModule
          -{
          +class�NetworkModule�{
           ����@Provides
           ����@Singleton
           ����fun�provideOkHttpClient():�OkHttpClient�{
          @@ -24,7 +23,7 @@
           ����@Provides
           ����@Singleton
          -����fun�provideProgrammingQuotesApi(okHttpClient:�OkHttpClient)�:�ProgrammingQuotesApi�{
          +����fun�provideProgrammingQuotesApi(okHttpClient:�OkHttpClient):�ProgrammingQuotesApi�{
           ��������return�Retrofit.Builder()
      ... (8 more lines that didn't fit)

Command Prompt's output (Windows 10)

Execution failed for task ':app:spotlessKotlinCheck'.
> The following files had format violations:
      app\src\main\java\com\corwinjv\postmodernandroid\common\di\NetworkModule.kt
          @@ -6,15 +6,14 @@
           import╖dagger.Provides
           import╖dagger.hilt.InstallIn
           import╖dagger.hilt.android.components.ApplicationComponent
          +import╖javax.inject.Singleton
           import╖okhttp3.OkHttpClient
           import╖retrofit2.Retrofit
           import╖retrofit2.converter.gson.GsonConverterFactory
          -import╖javax.inject.Singleton

           @InstallIn(ApplicationComponent::class)
           @Module
          -class╖NetworkModule
          -{
          +class╖NetworkModule╖{
           ╖╖╖╖@Provides
           ╖╖╖╖@Singleton
           ╖╖╖╖fun╖provideOkHttpClient():╖OkHttpClient╖{
          @@ -24,7 +23,7 @@

           ╖╖╖╖@Provides
           ╖╖╖╖@Singleton
          -╖╖╖╖fun╖provideProgrammingQuotesApi(okHttpClient:╖OkHttpClient)╖:╖ProgrammingQuotesApi╖{
          +╖╖╖╖fun╖provideProgrammingQuotesApi(okHttpClient:╖OkHttpClient):╖ProgrammingQuotesApi╖{
           ╖╖╖╖╖╖╖╖return╖Retrofit.Builder()
      ... (8 more lines that didn't fit)

Android Studio 4.0's output (Mac OS Catalina)

Execution failed for task ':app:spotlessKotlinCheck'.
> The following files had format violations:
      app/src/androidTest/java/com/corwinjv/postmodernandroid/ExampleInstrumentedTest.kt
          @@ -1,13 +1,11 @@
           package·com.corwinjv.postmodernandroid
           
          +import·androidx.test.ext.junit.runners.AndroidJUnit4
           import·androidx.test.platform.app.InstrumentationRegistry
          -import·androidx.test.ext.junit.runners.AndroidJUnit4
          -
          +import·org.junit.Assert.assertEquals
           import·org.junit.Test
           import·org.junit.runner.RunWith
           
          -import·org.junit.Assert.assertEquals
          -
           /**
           ·*·Instrumented·test,·which·will·execute·on·an·Android·device.
           ·*
      app/src/main/java/com/corwinjv/postmodernandroid/App.kt
          @@ -4,4 +4,4 @@
           import·dagger.hilt.android.HiltAndroidApp
           
           @HiltAndroidApp
          -class·App·:·Application()
          +class·App·:·Application()
      app/src/main/java/com/corwinjv/postmodernandroid/common/di/NetworkModule.kt
          @@ -6,15 +6,14 @@
           import·dagger.Provides
           import·dagger.hilt.InstallIn
           import·dagger.hilt.android.components.ApplicationComponent
          +import·javax.inject.Singleton
           import·okhttp3.OkHttpClient
           import·retrofit2.Retrofit
           import·retrofit2.converter.gson.GsonConverterFactory
          -import·javax.inject.Singleton
           
           @InstallIn(ApplicationComponent::class)
           @Module
          -class·NetworkModule
          -{
          +class·NetworkModule·{
           ····@Provides
           ····@Singleton
           ····fun·provideOkHttpClient():·OkHttpClient·{
          @@ -24,7 +23,7 @@
           
           ····@Provides
           ····@Singleton
          -····fun·provideProgrammingQuotesApi(okHttpClient:·OkHttpClient)·:·ProgrammingQuotesApi·{
          +····fun·provideProgrammingQuotesApi(okHttpClient:·OkHttpClient):·ProgrammingQuotesApi·{
           ········return·Retrofit.Builder()
      ... (8 more lines that didn't fit)

gradle or maven version

Gradle - 6.1.1

spotless version

5.5.1

operating system and version

• Windows 10 Pro (19041.508)
• Android Studio 4.0
• Intellij IDEA 2019.3.4

copy-paste your full Spotless configuration block(s)

Root project Gradle file

buildscript {
    repositories {
        // ...
        maven { url "https://plugins.gradle.org/m2/" }
    }
    dependencies {
        // ...
        classpath 'com.android.tools.build:gradle:4.0.1'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.4.0"
        classpath "com.diffplug.spotless:spotless-plugin-gradle:5.5.1"
    }
}

apply plugin: "com.diffplug.spotless"
// ...

Subproject (app)'s Gradle file

// ...
apply plugin: "com.diffplug.spotless"

spotless {
    kotlin {
        target 'src/*/java/**/*.kt'
        ktlint()
    }
}
// ...

copy-paste the full content of any console errors emitted by gradlew spotless[Apply/Check] --stacktrace

See summary