Lint rule to fix the space assignment syntax (#415)

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https://services.gradle.org/distributions/gradle-8.11.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.12-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME

gradlew

@@ -86,8 +86,7 @@ done
 # shellcheck disable=SC2034
 APP_BASE_NAME=${0##*/}
 # Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
-APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s
-' "$PWD" ) || exit
+APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s\n' "$PWD" ) || exit
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD=maximum

src/main/groovy/com/netflix/nebula/lint/rule/GradleLintRule.groovy

@@ -20,16 +20,7 @@ import com.netflix.nebula.lint.GradleViolation
 import com.netflix.nebula.lint.plugin.LintRuleRegistry
 import org.codehaus.groovy.ast.ASTNode
 import org.codehaus.groovy.ast.ClassNode
-import org.codehaus.groovy.ast.expr.ArgumentListExpression
-import org.codehaus.groovy.ast.expr.BinaryExpression
-import org.codehaus.groovy.ast.expr.ClosureExpression
-import org.codehaus.groovy.ast.expr.ConstantExpression
-import org.codehaus.groovy.ast.expr.Expression
-import org.codehaus.groovy.ast.expr.GStringExpression
-import org.codehaus.groovy.ast.expr.MapExpression
-import org.codehaus.groovy.ast.expr.MethodCallExpression
-import org.codehaus.groovy.ast.expr.PropertyExpression
-import org.codehaus.groovy.ast.expr.VariableExpression
+import org.codehaus.groovy.ast.expr.*
 import org.codehaus.groovy.ast.stmt.ExpressionStatement
 import org.codenarc.rule.AbstractAstVisitorRule
 import org.codenarc.rule.AstVisitor
@@ -43,7 +34,6 @@ import org.slf4j.LoggerFactory
 import java.text.ParseException
 
 abstract class GradleLintRule extends GroovyAstVisitor implements Rule {
-    Project project // will be non-null if type is GradleModelAware, otherwise null
     BuildFiles buildFiles
     SourceCode sourceCode
     List<GradleViolation> gradleViolations = []
@@ -152,6 +142,21 @@ abstract class GradleLintRule extends GroovyAstVisitor implements Rule {
         calls.collect { call -> _dslStack(call) }.flatten() as List<String>
     }
 
+    final List<Expression> typedDslStack(List<MethodCallExpression> calls) {
+        def _dslStack
+        _dslStack = { Expression expr ->
+            if (expr instanceof PropertyExpression)
+                _dslStack(expr.objectExpression) + expr.property
+            else if (expr instanceof MethodCallExpression)
+                _dslStack(expr.objectExpression) + expr
+            else if (expr instanceof VariableExpression)
+                expr.text == 'this' ? [] : [expr]
+            else []
+        }
+
+        calls.collect { call -> _dslStack(call) }.flatten() as List<String>
+    }
+
     private final String containingConfiguration(MethodCallExpression call) {
         def stackStartingWithConfName = dslStack(callStack + call).dropWhile { it != 'configurations' }.drop(1)
         stackStartingWithConfName.isEmpty() ? null : stackStartingWithConfName[0]

src/main/groovy/com/netflix/nebula/lint/rule/GradleModelAware.groovy

@@ -16,12 +16,194 @@
 
 package com.netflix.nebula.lint.rule
 
+import org.codehaus.groovy.ast.expr.*
+import org.gradle.api.Action
 import org.gradle.api.Project
+import org.gradle.api.Task
+import org.gradle.api.internal.DefaultDomainObjectCollection
+import org.gradle.api.plugins.ExtensionAware
+import org.gradle.configuration.ImportsReader
+
+import javax.annotation.Nullable
 
 /**
  * Decorate lint rule visitors with this interface in order to use the
  * evaluated Gradle project model in the rule
  */
-interface GradleModelAware {
-    void setProject(Project project)
+trait GradleModelAware {
+    Project project
+    Map<String, List<String>> projectDefaultImports = null
+
+    TypeInformation receiver(MethodCallExpression call) {
+        List<Expression> fullCallStack = typedDslStack(callStack + call)
+        List<TypeInformation> typedStack = []
+        for (Expression currentMethod in fullCallStack) {
+            if (typedStack.empty) {
+                typedStack.add(new TypeInformation(project))
+            }
+            while (!typedStack.empty) {
+                def current = typedStack.last()
+                def candidate = findDirectCandidate(current, currentMethod)
+                if (candidate != null) {
+                    typedStack.add(candidate)
+                    break
+                }
+                typedStack.removeLast()
+            }
+        }
+        if (typedStack.size() >= 2) { //there should be the method return type and the receiver at least
+            return typedStack[-2]
+        } else {
+            return null
+        }
+    }
+
+    private findDirectCandidate(TypeInformation current, Expression currentExpression) {
+        String methodName
+        switch (currentExpression) {
+            case MethodCallExpression:
+                methodName = currentExpression.methodAsString
+                break
+            case PropertyExpression:
+                methodName = currentExpression.propertyAsString
+                break
+            case VariableExpression:
+                methodName = currentExpression.text
+                break
+            case ConstantExpression:
+                methodName = currentExpression.text
+                break
+            default:
+                return null
+        }
+        def getter = current.clazz.getMethods().find { it.name == "get${methodName.capitalize()}" }
+        if (getter != null) {
+            if (current.object != null) {
+                try {
+                    return new TypeInformation(getter.invoke(current.object))
+                } catch (ignored) {
+                    // ignore and fallback to the return type
+                }
+            }
+            return new TypeInformation(null, getter.returnType)
+        }
+
+        // there is no public API for DomainObjectCollection.type
+        if (current.object != null && DefaultDomainObjectCollection.class.isAssignableFrom(current.clazz)) {
+            def collectionItemType = ((DefaultDomainObjectCollection) current.object).type
+
+            if (methodName == "withType" && currentExpression instanceof MethodCallExpression && currentExpression.arguments.size() >= 1) {
+                def className = currentExpression.arguments[0]
+                def candidate = findSuitableClass(className.text, collectionItemType)
+                if (candidate != null) {
+                    collectionItemType = candidate
+                }
+            }
+
+            if ((methodName == "create" || methodName == "register") && currentExpression instanceof MethodCallExpression && currentExpression.arguments.size() >= 2 && currentExpression.arguments[1] !instanceof ClosureExpression) {
+                def className = currentExpression.arguments[1]
+                def candidate = findSuitableClass(className.text, collectionItemType)
+                if (candidate != null) {
+                    collectionItemType = candidate
+                }
+            }
+
+            def transformationOrFactoryMethod = current.clazz.getMethods().find { it.name == methodName && it.parameterTypes[-1] == Action.class }
+            if (transformationOrFactoryMethod != null) {
+                if (collectionItemType.isAssignableFrom(transformationOrFactoryMethod.returnType)) {
+                    return new TypeInformation(null, transformationOrFactoryMethod.returnType)
+                } else {
+                    // assume that all actions are done on the collection type
+                    return new TypeInformation(null, collectionItemType)
+                }
+            }
+        }
+
+        // note that we can't use tasks.findByName because it may lead to unwanted side effects because of potential task creation
+        if (Project.class.isAssignableFrom(current.clazz) && methodName == "task" && currentExpression instanceof MethodCallExpression) {
+            def taskType = extractTaskType(currentExpression)
+            if (taskType != null) {
+                return new TypeInformation(null, taskType)
+            }
+            return new TypeInformation(null, Task.class)
+        }
+
+        def factoryMethod = current.clazz.getMethods().find { it.name == methodName && it.parameterTypes[-1] == Action.class }
+        if (factoryMethod != null) {
+            // assume that this is a factory method that returns the created type
+            return new TypeInformation(null, factoryMethod.returnType)
+        }
+
+        if (current.object != null && current.object instanceof ExtensionAware) {
+            def extension = current.object.extensions.findByName(methodName)
+            if (extension != null) {
+                return new TypeInformation(extension)
+            }
+        }
+        return null;
+    }
+
+    private List<Class> findClassInScope(String name) {
+        if (this.projectDefaultImports == null) {
+            this.projectDefaultImports = project.services.get(ImportsReader.class).getSimpleNameToFullClassNamesMapping()
+        }
+        return this.projectDefaultImports.get(name);
+    }
+
+    @Nullable
+    private Class findSuitableClass(String className, Class parentClass) {
+        def candidates = (findClassInScope(className) ?: []) + [className]
+        for (String candidate in candidates) {
+            try {
+                def candidateClass = Class.forName(candidate)
+                if (parentClass.isAssignableFrom(candidateClass)) {
+                    return candidateClass
+                }
+            } catch (ignored) {
+                // ignore and try the next candidate
+            }
+        }
+        return null
+    }
+
+    @Nullable
+    private Class extractTaskType(MethodCallExpression currentExpression) {
+        for (Expression arg in currentExpression.arguments) {
+            if (arg instanceof VariableExpression || arg instanceof ConstantExpression) {
+                def candidate = findSuitableClass(arg.text, Task.class)
+                if (candidate != null) {
+                    return candidate
+                }
+            } else if (arg instanceof MapExpression) {
+                def type = arg
+                        .mapEntryExpressions
+                        .find { it.keyExpression.text == "type" }
+                        ?.valueExpression?.text
+                if (type != null) {
+                    def candidate = findSuitableClass(type, Task.class)
+                    if (candidate != null) {
+                        return candidate
+                    }
+                }
+            }
+        }
+        return null
+    }
+}
+
+class TypeInformation {
+    @Nullable
+    Class clazz
+    @Nullable
+    Object object
+
+    TypeInformation(Object object) {
+        this.object = object
+        this.clazz = object.class
+    }
+
+    TypeInformation(Object object, Class clazz) {
+        this.object = object
+        this.clazz = clazz
+    }
 }

src/main/groovy/com/netflix/nebula/lint/rule/dsl/SpaceAssignmentRule.groovy

@@ -0,0 +1,50 @@
+package com.netflix.nebula.lint.rule.dsl
+
+import com.netflix.nebula.lint.rule.GradleLintRule
+import com.netflix.nebula.lint.rule.GradleModelAware
+import org.codehaus.groovy.ast.expr.ClosureExpression
+import org.codehaus.groovy.ast.expr.MethodCallExpression
+
+class SpaceAssignmentRule extends GradleLintRule implements GradleModelAware {
+
+    String description = "space-assignment syntax is deprecated"
+
+    @Override
+    void visitMethodCallExpression(MethodCallExpression call) {
+        if (call.arguments.size() != 1 || call.arguments[-1] instanceof ClosureExpression) {
+            return
+        }
+
+        def receiverClass = receiver(call)?.clazz
+        if (receiverClass == null) {
+            return // no enough data to analyze
+        }
+
+        def invokedMethodName = call.method.value
+
+        // check if the method has a matching property
+        def setter = receiverClass.getMethods().find { it.name == "set${invokedMethodName.capitalize()}" }
+        if (setter == null) {
+            return // no matching property
+        }
+
+        // check if it's a generated method for space assignment
+        def exactMethod = receiverClass.getMethods().find { it.name == invokedMethodName }
+        if (exactMethod != null) {
+            def deprecatedAnnotation = exactMethod.getAnnotation(Deprecated)
+            if (deprecatedAnnotation != null) {
+                // may be false positive when the explicit method is deprecated
+                addBuildLintViolation(description, call)
+                        .replaceWith(call, getReplacement(call))
+            }
+        } else {
+            addBuildLintViolation(description, call)
+                    .replaceWith(call, getReplacement(call))
+        }
+    }
+
+    def getReplacement(MethodCallExpression call){
+        def originalLine = getSourceCode().line(call.lineNumber-1)
+        return originalLine.replaceFirst(call.methodAsString, call.methodAsString + " =")
+    }
+}

src/main/resources/META-INF/lint-rules/space-assignment.properties

@@ -0,0 +1 @@
+implementation-class=com.netflix.nebula.lint.rule.dsl.SpaceAssignmentRule