==== tests/cases/compiler/collisionArgumentsClassMethod.ts (4 errors) ==== class c1 { public foo(i: number, ...arguments) { //arguments is error ~~~~~~~~~~~~ !!! Duplicate identifier 'arguments'. Compiler uses 'arguments' to initialize rest parameters. var arguments: any[]; // no error } public foo1(arguments: number, ...rest) { //arguments is error ~~~~~~~~~~~~~~~~~ !!! Duplicate identifier 'arguments'. Compiler uses 'arguments' to initialize rest parameters. var arguments = 10; // no error } public fooNoError(arguments: number) { // no error var arguments = 10; // no error } public f4(i: number, ...arguments); // no codegen no error public f4(i: string, ...arguments); // no codegen no error public f4(i: any, ...arguments) { // error ~~~~~~~~~~~~ !!! Duplicate identifier 'arguments'. Compiler uses 'arguments' to initialize rest parameters. var arguments: any[]; // no error } public f41(arguments: number, ...rest); // no codegen no error public f41(arguments: string, ...rest); // no codegen no error public f41(arguments: any, ...rest) { // error ~~~~~~~~~~~~~~ !!! Duplicate identifier 'arguments'. Compiler uses 'arguments' to initialize rest parameters. var arguments: any; // no error } public f4NoError(arguments: number); // no error public f4NoError(arguments: string); // no error public f4NoError(arguments: any) { // no error var arguments: any; // no error } } declare class c2 { public foo(i: number, ...arguments); // No error - no code gen public foo1(arguments: number, ...rest); // No error - no code gen public fooNoError(arguments: number); // No error - no code gen public f4(i: number, ...arguments); // no codegen no error public f4(i: string, ...arguments); // no codegen no error public f41(arguments: number, ...rest); // no codegen no error public f41(arguments: string, ...rest); // no codegen no error public f4NoError(arguments: number); // no error public f4NoError(arguments: string); // no error } class c3 { public foo(...restParameters) { var arguments = 10; // no error } public fooNoError() { var arguments = 10; // no error } }