feat: switch ktlint for spotless (#1093)

Using `ktlint` directly as gradle task is very powerful and flexible but due to problems (#1085, #1090) we've decided to use formatting/linting framework - Spotless.

android/build.gradle

@@ -10,6 +10,10 @@ buildscript {
     }
 }
 
+plugins {
+    id "com.diffplug.spotless" version "5.14.1"
+}
+
 apply plugin: 'com.android.library'
 apply plugin: 'kotlin-android'
 
@@ -55,26 +59,14 @@ dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.5.20"
 }
 
-configurations {
-    ktlint
-}
-
-dependencies {
-    ktlint "com.pinterest:ktlint:0.40.0"
-}
-
-task ktlint(type: JavaExec, group: "verification") {
-    description = "Check Kotlin code style."
-    main = "com.pinterest.ktlint.Main"
-    classpath = configurations.ktlint
-    args project.findProperty("file") ?: "src/**/*.kt"
-}
+plugins.apply("com.diffplug.spotless")
 
-check.dependsOn ktlint
-
-task ktlintFormat(type: JavaExec, group: "formatting") {
-    description = "Fix Kotlin code style deviations."
-    main = "com.pinterest.ktlint.Main"
-    classpath = configurations.ktlint
-    args "-F", project.findProperty("file") ?: "src/**/*.kt"
+spotless {
+    kotlin {
+        target 'src/**/*.kt'
+        ktlint("0.40.0")
+        trimTrailingWhitespace()
+        indentWithSpaces()
+        endWithNewline()
+    }
 }

package.json

@@ -11,7 +11,7 @@
     "format-ios": "find ios/ -iname *.h -o -iname *.m -o -iname *.cpp | xargs clang-format -i",
     "format": "yarn format-js && yarn format-android && yarn format-ios",
     "lint-js": "eslint --ext '.js,.ts,.tsx' --fix src",
-    "lint-android": "node ./scripts/lint-android.js",
+    "lint-android": "./android/gradlew -p android spotlessCheck -q",
     "lint": "yarn lint-js && yarn lint-android",
     "release": "npm login && release-it",
     "prepare": "bob build && husky install"
@@ -103,13 +103,8 @@
   "lint-staged": {
     "{src,Example}/**/*.{js,ts,tsx}": "yarn format-js",
     "src/**/*.{js,ts,tsx}": "yarn lint-js",
-    "android/**/*.kt": [
-      "yarn format-android",
-      "yarn lint-android"
-    ],
-    "ios/**/*.{h,m,cpp}": [
-      "yarn format-ios"
-    ]
+    "android/**/*.kt": "yarn format-android",
+    "ios/**/*.{h,m,cpp}": "yarn format-ios"
   },
   "@react-native-community/bob": {
     "source": "src",

scripts/format-android.js

@@ -1,19 +1,24 @@
 /* 
- * This script is a wrapper for gradle & ktlintFormat to make
+ * This script is a wrapper for gradle & spotlessApply to make
  * it work properly with lint-staged.
  */
 
 const { exit } = require("process");
 const { exec } = require("child_process");
 
-// ktlintFormat task in android/build.gradle
-const ktlintFormatCommand = "./android/gradlew -p android ktlintFormat -q -Pfile="
+// spotless ktlint formatting task in android/build.gradle
+const spotlessApply = "./android/gradlew -p android spotlessApply";
 
 // takes file as parameter passed by lint-staged (optional)
-const fileName = process.argv[2] !== undefined ? process.argv[2] : '';
+const fileName = process.argv[2];
 
-// executes command with file parameter without space between them
-exec(`${ktlintFormatCommand}${fileName}`, (error, stdout) => {
+// https://github.com/diffplug/spotless/blob/main/plugin-gradle/IDE_HOOK.md
+// creates file argument without space between arguments
+const fileArgument = `-PspotlessIdeHook=${fileName}`;
+
+const command = fileName !== undefined ? `${spotlessApply} ${fileArgument}` : spotlessApply;
+
+exec(command, (error, stdout) => {
   if (error) {
     console.log(error);
     console.log(stdout);