Add Spotless to regulate codestyle (#550)

* Add Spotless to regulate codestyle

* treewide: Run spotless

* Add spotlessCheck to CI test

Signed-off-by: Harsh Shandilya <msfjarvis@gmail.com>

2 files changed, 63 insertions, 0 deletions

diff --git a/buildSrc/build.gradle.kts b/buildSrc/build.gradle.kts
new file mode 100644
index 00000000..8c3ae64d
--- /dev/null
+++ b/buildSrc/build.gradle.kts
@@ -0,0 +1,16 @@
+plugins {
+    `kotlin-dsl`
+}
+
+repositories {
+    maven("https://plugins.gradle.org/m2/")
+    jcenter()
+}
+
+kotlinDslPluginOptions {
+    experimentalWarning.set(false)
+}
+
+dependencies {
+    implementation("com.diffplug.spotless:spotless-plugin-gradle:3.24.3")
+}
diff --git a/buildSrc/src/main/kotlin/SpotlessConfiguration.kt b/buildSrc/src/main/kotlin/SpotlessConfiguration.kt
new file mode 100644
index 00000000..3c183c5f
--- /dev/null
+++ b/buildSrc/src/main/kotlin/SpotlessConfiguration.kt
@@ -0,0 +1,47 @@
+import com.diffplug.gradle.spotless.SpotlessExtension
+import com.diffplug.gradle.spotless.SpotlessPlugin
+import org.gradle.api.Project
+import org.gradle.kotlin.dsl.apply
+import org.gradle.kotlin.dsl.configure
+
+val kotlinLicenseHeader = """/*
+ * Copyright © 2014-2019 The Android Password Store Authors. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-2.0
+ */
+""".trimIndent()
+
+fun Project.configureSpotless() {
+    apply<SpotlessPlugin>()
+
+    configure<SpotlessExtension> {
+        java {
+            target("**/src/main/**/*.java")
+            trimTrailingWhitespace()
+            // @Suppress("INACCESSIBLE_TYPE")
+            // licenseHeader(kotlinLicenseHeader)
+            removeUnusedImports()
+            googleJavaFormat().aosp()
+            endWithNewline()
+        }
+
+        kotlinGradle {
+            target("*.gradle.kts", "gradle/*.gradle.kts", "buildSrc/*.gradle.kts")
+            ktlint("0.31.0").userData(mapOf("indent_size" to "4", "continuation_indent_size" to "4"))
+            // @Suppress("INACCESSIBLE_TYPE")
+            // licenseHeader(kotlinLicenseHeader, "import|tasks|apply|plugins|include")
+            trimTrailingWhitespace()
+            indentWithSpaces()
+            endWithNewline()
+        }
+
+        kotlin {
+            target("**/src/main/**/*.kt", "buildSrc/**/*.kt")
+            ktlint("0.31.0").userData(mapOf("indent_size" to "4", "continuation_indent_size" to "4"))
+            // @Suppress("INACCESSIBLE_TYPE")
+            // licenseHeader(kotlinLicenseHeader)
+            trimTrailingWhitespace()
+            indentWithSpaces()
+            endWithNewline()
+        }
+    }
+}