Analysis Details

Always override toString

es.uniovi.reflection.analyses.bloch.3.10

This rule detects classes not implementing/redefining the toString method when this method is being invoked somewhere in the code.

Computational Reflection Research Group

01-05-2026 13:28

Reliability

Type Declaration

MATCH (typeMemberSelection)<-[:ITS_TYPE_IS]-(leftExpression)<-[IDENT_SELECTION_FROM*0..1]-(methodReference)<-[:INVOCATION_METHOD_SELECTION]-(invocation:METHOD_INVOCATION)<-[:CALLS]-(method)<-[:DECLARES_METHOD]-(typeDefinition)<-[:DECLARES_TYPE| HAS_NESTED_TYPE]-(enclosingCU:ORDINARY_CU)
WHERE (methodReference.name='toString' OR methodReference.selectedName='toString') AND methodReference.actualType = '()java.lang.String'
WITH CASE WHEN methodReference:METHOD_IDENTIFIER THEN typeDefinition ELSE typeMemberSelection END AS classType, invocation, typeDefinition, enclosingCU
MATCH (enclosCU:ORDINARY_CU)-[:DECLARES_TYPE| HAS_NESTED_TYPE]->(classType)
OPTIONAL MATCH (classType)-[:DECLARES_METHOD]->(methodToString)
WHERE methodToString.name='toString' AND methodToString.actualType='()java.lang.String'
WITH classType, enclosingCU, apoc.text.join(COLLECT( DISTINCT invocation.lineNumber+''),',') as invLines, methodToString, typeDefinition
WHERE methodToString IS NULL
RETURN DISTINCT '{"node":"'+classType.fullyQualifiedName+'","line":"'+classType.lineNumber+'","column":"'+classType.column+'","rule":"BLOCH-3.10","location":"'+enclosingCU.fileName+'","message":"You should override the toString method in class '+classType.fullyQualifiedName+', since it is being invoked in '+typeDefinition.fullyQualifiedName+', at line(s) '+ invLines +'."}'