Assertions in Switch Expressions lead to compiler error

[joshuabrandes]

Describe the bug

Version: 2.4-M1-groovy-4.0

I have a test case where I need to get content form a map and assert its value. I first tried it with a switch expression and build a example I can share:

class MathTest extends Specification {

    def "test square"() {
        setup: "two numbers"
        var b = 2
        Map<Integer, Integer> map = new HashMap<>()
        map.put(b, Main.square(b))

        expect: "squaring the number"
        switch (b) {
            case 2 -> map.get(b) == 4
            default -> throw new Exception("Not implemented")
        }
    }
}

When I ant to run this test I get the following build output:

Groovyc: While compiling [tests of spock-testing]: Unexpected error during compilation of spec 'MathTest'. Maybe you have used invalid Spock syntax? Anyway, please file a bug report at https://issues.spockframework.org.

java.lang.ClassCastException: class org.codehaus.groovy.ast.stmt.AssertStatement cannot be cast to class org.codehaus.groovy.ast.stmt.BlockStatement (org.codehaus.groovy.ast.stmt.AssertStatement and org.codehaus.groovy.ast.stmt.BlockStatement are in unnamed module of loader org.jetbrains.jps.incremental.groovy.JointCompilationClassLoader @43b8b9ec)
	at org.spockframework.compiler.AstUtil.getStatements(AstUtil.java:88)
	at org.spockframework.compiler.DeepBlockRewriter.defineRecorders(DeepBlockRewriter.java:305)
	at org.spockframework.compiler.DeepBlockRewriter.doVisitClosureExpression(DeepBlockRewriter.java:136)
	at org.spockframework.compiler.AbstractDeepBlockRewriter.visitClosureExpression(AbstractDeepBlockRewriter.java:152)
	at org.codehaus.groovy.ast.expr.ClosureExpression.visit(ClosureExpression.java:110)
	at org.codehaus.groovy.ast.CodeVisitorSupport.visitMethodCallExpression(CodeVisitorSupport.java:184)
	at org.spockframework.compiler.AbstractDeepBlockRewriter.doVisitMethodCallExpression(AbstractDeepBlockRewriter.java:170)
	at org.spockframework.compiler.DeepBlockRewriter.doVisitMethodCallExpression(DeepBlockRewriter.java:148)
	at org.spockframework.compiler.AbstractDeepBlockRewriter.visitMethodCallExpression(AbstractDeepBlockRewriter.java:132)
	at org.codehaus.groovy.ast.expr.MethodCallExpression.visit(MethodCallExpression.java:77)
	at org.codehaus.groovy.ast.CodeVisitorSupport.visitReturnStatement(CodeVisitorSupport.java:122)
	at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitReturnStatement(ClassCodeVisitorSupport.java:222)
	at org.codehaus.groovy.ast.stmt.ReturnStatement.visit(ReturnStatement.java:73)
	at org.spockframework.compiler.StatementReplacingVisitorSupport.replace(StatementReplacingVisitorSupport.java:44)
	at org.spockframework.compiler.StatementReplacingVisitorSupport.replaceAll(StatementReplacingVisitorSupport.java:59)
	at org.spockframework.compiler.StatementReplacingVisitorSupport.visitBlockStatement(StatementReplacingVisitorSupport.java:72)
	at org.codehaus.groovy.ast.stmt.BlockStatement.visit(BlockStatement.java:70)
	at org.spockframework.compiler.StatementReplacingVisitorSupport.replace(StatementReplacingVisitorSupport.java:44)
	at org.spockframework.compiler.StatementReplacingVisitorSupport.visitCaseStatement(StatementReplacingVisitorSupport.java:119)
	at org.codehaus.groovy.ast.stmt.CaseStatement.visit(CaseStatement.java:56)
	at org.spockframework.compiler.StatementReplacingVisitorSupport.replace(StatementReplacingVisitorSupport.java:44)
	at org.spockframework.compiler.StatementReplacingVisitorSupport.replaceAll(StatementReplacingVisitorSupport.java:59)
	at org.spockframework.compiler.StatementReplacingVisitorSupport.visitSwitch(StatementReplacingVisitorSupport.java:112)
	at org.codehaus.groovy.ast.stmt.SwitchStatement.visit(SwitchStatement.java:54)
	at org.spockframework.compiler.StatementReplacingVisitorSupport.replace(StatementReplacingVisitorSupport.java:44)
	at org.spockframework.compiler.StatementReplacingVisitorSupport.replaceAll(StatementReplacingVisitorSupport.java:59)
	at org.spockframework.compiler.StatementReplacingVisitorSupport.visitBlockStatement(StatementReplacingVisitorSupport.java:72)
	at org.codehaus.groovy.ast.stmt.BlockStatement.visit(BlockStatement.java:70)
	at org.codehaus.groovy.ast.CodeVisitorSupport.visitClosureExpression(CodeVisitorSupport.java:239)
	at org.spockframework.compiler.AbstractDeepBlockRewriter.doVisitClosureExpression(AbstractDeepBlockRewriter.java:174)
	at org.spockframework.compiler.DeepBlockRewriter.doVisitClosureExpression(DeepBlockRewriter.java:135)
	at org.spockframework.compiler.AbstractDeepBlockRewriter.visitClosureExpression(AbstractDeepBlockRewriter.java:152)
	at org.codehaus.groovy.ast.expr.ClosureExpression.visit(ClosureExpression.java:110)
	at org.codehaus.groovy.ast.CodeVisitorSupport.visitMethodCallExpression(CodeVisitorSupport.java:184)
	at org.spockframework.compiler.AbstractDeepBlockRewriter.doVisitMethodCallExpression(AbstractDeepBlockRewriter.java:170)
	at org.spockframework.compiler.DeepBlockRewriter.doVisitMethodCallExpression(DeepBlockRewriter.java:148)
	at org.spockframework.compiler.AbstractDeepBlockRewriter.visitMethodCallExpression(AbstractDeepBlockRewriter.java:132)
	at org.codehaus.groovy.ast.expr.MethodCallExpression.visit(MethodCallExpression.java:77)
	at org.codehaus.groovy.ast.CodeVisitorSupport.visitExpressionStatement(CodeVisitorSupport.java:117)
	at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitExpressionStatement(ClassCodeVisitorSupport.java:204)
	at org.spockframework.compiler.AbstractDeepBlockRewriter.doVisitExpressionStatement(AbstractDeepBlockRewriter.java:162)
	at org.spockframework.compiler.DeepBlockRewriter.visitInteractionAwareExpressionStatement(DeepBlockRewriter.java:96)
	at org.spockframework.compiler.DeepBlockRewriter.doVisitExpressionStatement(DeepBlockRewriter.java:78)
	at org.spockframework.compiler.AbstractDeepBlockRewriter.visitExpressionStatement(AbstractDeepBlockRewriter.java:100)
	at org.codehaus.groovy.ast.stmt.ExpressionStatement.visit(ExpressionStatement.java:41)
	at org.spockframework.compiler.StatementReplacingVisitorSupport.replace(StatementReplacingVisitorSupport.java:44)
	at org.spockframework.compiler.AbstractDeepBlockRewriter.visit(AbstractDeepBlockRewriter.java:84)
	at org.spockframework.compiler.DeepBlockRewriter.visit(DeepBlockRewriter.java:56)
	at org.spockframework.compiler.SpecRewriter.visitAnyBlock(SpecRewriter.java:405)
	at org.spockframework.compiler.model.ExpectBlock.accept(ExpectBlock.java:31)
	at org.spockframework.compiler.model.Method.accept(Method.java:70)
	at org.spockframework.compiler.model.Spec.accept(Spec.java:112)
	at org.spockframework.compiler.SpockTransform$Impl.processSpec(SpockTransform.java:76)
	at org.spockframework.compiler.SpockTransform$Impl.visit(SpockTransform.java:63)
	at org.spockframework.compiler.SpockTransform.visit(SpockTransform.java:48)
	at org.codehaus.groovy.transform.ASTTransformationVisitor.lambda$addPhaseOperationsForGlobalTransforms$5(ASTTransformationVisitor.java:377)
	at org.codehaus.groovy.control.CompilationUnit$ISourceUnitOperation.doPhaseOperation(CompilationUnit.java:896)
	at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:692)
	at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:666)
	at org.jetbrains.groovy.compiler.rt.GroovyCompilerWrapper.compile(GroovyCompilerWrapper.java:48)
	at org.jetbrains.groovy.compiler.rt.DependentGroovycRunner.runGroovyc(DependentGroovycRunner.java:122)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
	at java.base/java.lang.reflect.Method.invoke(Method.java:578)
	at org.jetbrains.groovy.compiler.rt.GroovycRunner.intMain2(GroovycRunner.java:80)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
	at java.base/java.lang.reflect.Method.invoke(Method.java:578)
	at org.jetbrains.jps.incremental.groovy.InProcessGroovyc.runGroovycInThisProcess(InProcessGroovyc.java:167)
	at org.jetbrains.jps.incremental.groovy.InProcessGroovyc.lambda$runGroovyc$0(InProcessGroovyc.java:77)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
	at java.base/java.lang.Thread.run(Thread.java:1589)

To Reproduce

def "assert test"() {
    expect:
    def b = 3
    switch (b) {
        default -> assert 1 == 1
    }
}

Expected behavior

assertion is executed in the matching case

Actual behavior

compiler error

Java version

java version "21" 2023-09-19 LTS

Buildtool version

Apache Maven 3.8.5

What operating system are you using

Windows

Dependencies

--- maven-dependency-plugin:2.8:tree (default-cli) @ spock-testing ---
[INFO] org.example:spock-testing:jar:1.0-SNAPSHOT
[INFO] +- org.junit.jupiter:junit-jupiter-api:jar:5.8.2:test
[INFO] |  +- org.opentest4j:opentest4j:jar:1.2.0:compile
[INFO] |  +- org.junit.platform:junit-platform-commons:jar:1.8.2:compile
[INFO] |  \- org.apiguardian:apiguardian-api:jar:1.1.2:compile
[INFO] \- org.spockframework:spock-core:jar:2.4-M1-groovy-4.0:compile
[INFO]    +- org.apache.groovy:groovy:jar:4.0.6:compile
[INFO]    +- org.junit.platform:junit-platform-engine:jar:1.9.0:compile
[INFO]    \- org.hamcrest:hamcrest:jar:2.2:compile

Additional context

No response

[leonard84]

FWIW implicit assertions in if-blocks are ignored, so even if we fix the compile error, I'm not sure that we'd treat the branches of the switch-expression as implicit conditions.

In general I'd consider conditional logic in tests a code smell.
I know that practically might sometimes still make them necessary, but they should be avoided if possible.