tests/cases/compiler/collisionThisExpressionAndLocalVarInProperty.ts(4,17): error TS2399: Duplicate identifier '_this'. Compiler uses variable declaration '_this' to capture 'this' reference. tests/cases/compiler/collisionThisExpressionAndLocalVarInProperty.ts(12,13): error TS2399: Duplicate identifier '_this'. Compiler uses variable declaration '_this' to capture 'this' reference. ==== tests/cases/compiler/collisionThisExpressionAndLocalVarInProperty.ts (2 errors) ==== class class1 { public prop1 = { doStuff: (callback) => () => { var _this = 2; ~~~~~ !!! error TS2399: Duplicate identifier '_this'. Compiler uses variable declaration '_this' to capture 'this' reference. return callback(this); } } } class class2 { constructor() { var _this = 2; ~~~~~ !!! error TS2399: Duplicate identifier '_this'. Compiler uses variable declaration '_this' to capture 'this' reference. } public prop1 = { doStuff: (callback) => () => { return callback(this); } } }