feat(android): replace clang-format with gradle checkstyle

- "checkstyle" tool enforces Java coding standards and checks for common Java coding mistakes. Provides more readable error messages. - Applied checkstyle as a pre-build step to Java compile.
tidev · Mar 6, 2020 · 3cbc754 · 3cbc754
1 parent 6e066e0
commit 3cbc754
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diff --git a/android/app/build.gradle b/android/app/build.gradle
@@ -7,6 +7,7 @@
 
 apply plugin: 'com.android.application'
 
+// Set up Android app project.
 android {
 	compileSdkVersion 29
 	defaultConfig {
@@ -35,6 +36,18 @@ android {
 	}
 }
 
+// Checks our Java code against our style guidelines and for common coding mistakes using "checkstyle.xml".
+// Will trigger a build failure if any violations have been detected.
+task checkJavaStyle(type: Checkstyle) {
+	source android.sourceSets.main.java.srcDirs
+	include '**/*.java'
+	classpath = files()
+}
+tasks.withType(JavaCompile) {
+	dependsOn checkJavaStyle
+}
+
+// Define library dependencies used by this app.
 dependencies {
 	implementation(project(':titanium')) {
 // Uncomment the below to exclude Google Play Services from app.

diff --git a/android/build.gradle b/android/build.gradle
@@ -23,6 +23,17 @@ allprojects {
 		google()
 		jcenter()
 	}
+
+	// Load plugin used to enforce our Java coding style guidelines.
+	project.apply plugin: 'checkstyle'
+	checkstyle {
+		toolVersion = '8.30'
+		configFile file("${rootDir}/checkstyle.xml");
+		ignoreFailures false
+		showViolations true
+	}
+
+	// Include Titanium's gradle constants in all gradle sub-projects.
 	project.apply from: "${rootDir}/templates/build/ti.constants.gradle"
 }
 

diff --git a/android/checkstyle.xml b/android/checkstyle.xml
@@ -0,0 +1,117 @@
+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC
+	"-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+	"https://checkstyle.org/dtds/configuration_1_3.dtd">
+
+<!-- Used by gradle "Checkstyle" task to enforce Java coding guidelines and check for common mistakes. -->
+<module name="Checker">
+	<!-- Define number of spaces a single tab character should be. -->
+	<property name="tabWidth" value="4"/>
+
+	<!-- Do not allow lines of code to exceed 120 characters, except for comments. -->
+	<module name="LineLength">
+		<property name="max" value="120"/>
+		<property name="ignorePattern" value="\/\*|^\s*\*|\/\/"/>
+	</module>
+
+	<!-- Do not allow multiple empty lines in a row. -->
+	<module name="RegexpMultiline">
+		<property name="format" value="^\s*\n\s*\n"/>
+		<property name="message" value="You cannot have multiple empty lines."/>
+	</module>
+
+	<module name="TreeWalker">
+		<!-- Check import statements. -->
+		<!-- See: https://checkstyle.sourceforge.io/config_imports.html -->
+		<module name="AvoidStarImport"/>
+		<module name="IllegalImport"/>
+		<module name="UnusedImports"/>
+
+		<!-- Custom regex checks. -->
+		<!-- See: https://checkstyle.sourceforge.io/config_regexp.html -->
+		<module name="RegexpSinglelineJava">
+			<property name="format" value="^\t* {4}"/>
+			<property name="message" value="Must use tabs for indentation."/>
+			<property name="ignoreComments" value="true"/>
+		</module>
+		<module name="RegexpSinglelineJava">
+			<property name="format" value="\S+?[ \t]+?$"/>
+			<property name="message" value="Line cannot have whitespace at the end."/>
+			<property name="ignoreComments" value="true"/>
+		</module>
+
+		<!-- Checks for whitespace. -->
+		<!-- See: https://checkstyle.sourceforge.io/config_whitespace.html -->
+		<module name="EmptyLineSeparator">
+			<property name="allowMultipleEmptyLines" value="false"/>
+			<property name="allowMultipleEmptyLinesInsideClassMembers" value="false"/>
+			<property name="allowNoEmptyLineBetweenFields" value="true"/>
+			<property name="tokens" value="CLASS_DEF"/>
+		</module>
+		<module name="GenericWhitespace"/>
+		<module name="MethodParamPad"/>
+		<module name="NoWhitespaceAfter">
+			<property name="tokens" value="AT,INC,DEC,UNARY_MINUS,UNARY_PLUS,BNOT,LNOT,DOT,INDEX_OP"/>
+			<property name="allowLineBreaks" value="true"/>
+		</module>
+		<module name="NoWhitespaceBefore"/>
+		<module name="OperatorWrap"/>
+		<module name="ParenPad"/>
+		<module name="TypecastParenPad"/>
+		<module name="WhitespaceAfter"/>
+		<module name="WhitespaceAround">
+			<property name="allowEmptyCatches" value="true"/>
+			<property name="allowEmptyConstructors" value="true"/>
+			<property name="allowEmptyLambdas" value="true"/>
+			<property name="allowEmptyLoops" value="true"/>
+			<property name="allowEmptyMethods" value="true"/>
+			<property name="allowEmptyTypes" value="true"/>
+		</module>
+
+		<!-- Checks private/protected/public access modifiers. -->
+		<!-- See: https://checkstyle.sourceforge.io/config_modifier.html -->
+		<module name="RedundantModifier">
+			<property name="tokens" value="INTERFACE_DEF,METHOD_DEF"/>
+		</module>
+
+		<!-- Checks placement of curly braces. -->
+		<!-- See: https://checkstyle.sourceforge.io/config_blocks.html -->
+		<module name="LeftCurly">
+			<property name="option" value="nl"/>
+			<property name="tokens" value="CLASS_DEF,CTOR_DEF,LITERAL_SYNCHRONIZED,METHOD_DEF,STATIC_INIT"/>
+		</module>
+		<module name="LeftCurly">
+			<property name="option" value="eol"/>
+			<property name="tokens" value="
+				ANNOTATION_DEF,ENUM_CONSTANT_DEF,ENUM_DEF,INTERFACE_DEF,LAMBDA,LITERAL_CASE,LITERAL_CATCH,
+				LITERAL_DEFAULT,LITERAL_DO,LITERAL_ELSE,LITERAL_FINALLY,LITERAL_FOR,LITERAL_IF,LITERAL_SWITCH,
+				LITERAL_TRY,LITERAL_WHILE"/>
+		</module>
+		<module name="NeedBraces">
+			<property name="tokens" value="LITERAL_DO"/>
+		</module>
+
+		<!-- Check for miscellaneous issues. -->
+		<!-- See: https://checkstyle.sourceforge.io/config_misc.html -->
+		<module name="ArrayTypeStyle"/>
+		<module name="Indentation">
+			<property name="basicOffset" value="4"/>
+			<property name="braceAdjustment" value="0"/>
+			<property name="caseIndent" value="4"/>
+			<property name="throwsIndent" value="4"/>
+			<property name="lineWrappingIndentation" value="4"/>
+			<property name="arrayInitIndent" value="4"/>
+		</module>
+		<module name="OuterTypeFilename"/>
+		<module name="UpperEll"/>
+
+		<!-- Check for common coding mistakes. -->
+		<!-- See: https://checkstyle.sourceforge.io/config_coding.html -->
+		<module name="CovariantEquals"/>
+		<module name="EqualsHashCode"/>
+		<module name="IllegalInstantiation"/>
+		<module name="PackageDeclaration"/>
+		<module name="StringLiteralEquality"/>
+		<module name="UnnecessarySemicolonAfterTypeMemberDeclaration"/>
+	</module>
+</module>
diff --git a/android/kroll-apt/build.gradle b/android/kroll-apt/build.gradle
@@ -10,7 +10,19 @@ apply plugin: 'java'
 sourceCompatibility = JavaVersion.VERSION_1_8
 targetCompatibility = JavaVersion.VERSION_1_8
 
+// Checks our Java code against our style guidelines and for common coding mistakes using "checkstyle.xml".
+// Will trigger a build failure if any violations have been detected.
+task checkJavaStyle(type: Checkstyle) {
+	source 'src/main/java'
+	include '**/*.java'
+	classpath = files()
+}
+
+// Hook into Java compile task.
 tasks.withType(JavaCompile) {
+	// Check Java code for mistakes before compiling.
+	dependsOn checkJavaStyle
+
 	// Suppress compiler warning "bootstrap class path not set in conjunction with source" which happens when
 	// building with JDK newer than the Java version we're targeting. (Ex: Build with JDK 8, but target Java 7.)
 	// Note: Build tool wants a reference to runtime JAR of the same version we're targeting. Not going to happen.

diff --git a/package.json b/package.json
@@ -42,7 +42,7 @@
     "ios-sanity-check": "./build/scons check-ios-toplevel",
     "link": "npm run deploy -- --symlink",
     "lint": "npm-run-all --parallel lint:**",
-    "lint:android": "clang-format-lint $npm_package_config_format_android",
+    "lint:android": "echo Disabled in favor of gradle checkstyle tool.",
     "lint:docs": "tdoc-validate ./apidoc",
     "lint:ios": "clang-format-lint $npm_package_config_format_ios",
     "lint:js": "eslint .",
@@ -70,9 +70,6 @@
     "iphone/TitaniumKit/TitaniumKit/Sources/API/TopTiModule.m": [
       "npm run ios-sanity-check --"
     ],
-    "android/!(templates)/**/*.java": [
-      "npx clang-format -style=file -i"
-    ],
     "!(**/locales/**/*).js": "eslint"
   },
   "commitlint": {