constscopes=[];letcurrentScope={overloads:newMap(),parent:undefined,typeParameters:undefined};functioncreateScope(parent,typeParameters=undefined){scopes.push(currentScope);currentScope={overloads:newMap(),        parent,        typeParameters};}functioncheckScope(){constfailures=checkOverloads(Array.from(currentScope.overloads.values()),currentScope.typeParameters);addFailures(failures);currentScope=scopes.pop();}functionaddOverload(signature,key=null){key=key||getOverloadKey(signature);if(signature.parent===currentScope.parent&&key){constoverloads=currentScope.overloads.get(key);if(overloads!==undefined){overloads.push(signature);}else{currentScope.overloads.set(key,[signature]);}}}return{Program(node){createScope(node);},TSModuleBlock(node){createScope(node);},TSInterfaceDeclaration(node){createScope(node.body,node.typeParameters);},ClassDeclaration(node){createScope(node.body,node.typeParameters);},TSTypeLiteral(node){createScope(node);},// collect overloadsTSDeclareFunction(node){if(node.id&&!node.body){addOverload(node,node.id.name);}},TSCallSignatureDeclaration:addOverload,TSConstructSignatureDeclaration:addOverload,TSMethodSignature:addOverload,TSAbstractMethodDefinition(node){if(!node.value.body){addOverload(node);}},MethodDefinition(node){if(!node.value.body){addOverload(node);}},// validate scopes'Program:exit':checkScope,'TSModuleBlock:exit':checkScope,'TSInterfaceDeclaration:exit':checkScope,'ClassDeclaration:exit':checkScope,'TSTypeLiteral:exit':checkScope};