{ "type": "Program", "statements": [ { "type": "FunctionDeclaration", "function": { "type": "ScriptFunction", "id": { "type": "Identifier", "name": "a", "decorators": [], "loc": { "start": { "line": 17, "column": 10 }, "end": { "line": 17, "column": 11 } } }, "generator": false, "async": false, "expression": false, "params": [], "returnType": { "type": "TSTupleType", "elementTypes": [ { "type": "TSStringKeyword", "loc": { "start": { "line": 17, "column": 16 }, "end": { "line": 17, "column": 23 } } }, { "type": "TSNumberKeyword", "loc": { "start": { "line": 17, "column": 24 }, "end": { "line": 17, "column": 31 } } } ], "loc": { "start": { "line": 17, "column": 15 }, "end": { "line": 17, "column": 31 } } }, "body": { "type": "BlockStatement", "statements": [ { "type": "ReturnStatement", "argument": { "type": "ArrayExpression", "elements": [ { "type": "StringLiteral", "value": "foo", "loc": { "start": { "line": 18, "column": 13 }, "end": { "line": 18, "column": 18 } } }, { "type": "StringLiteral", "value": "bar", "loc": { "start": { "line": 18, "column": 20 }, "end": { "line": 18, "column": 25 } } } ], "loc": { "start": { "line": 18, "column": 12 }, "end": { "line": 18, "column": 26 } } }, "loc": { "start": { "line": 18, "column": 5 }, "end": { "line": 18, "column": 27 } } } ], "loc": { "start": { "line": 17, "column": 32 }, "end": { "line": 19, "column": 2 } } }, "loc": { "start": { "line": 17, "column": 1 }, "end": { "line": 19, "column": 2 } } }, "loc": { "start": { "line": 17, "column": 1 }, "end": { "line": 19, "column": 2 } } } ], "loc": { "start": { "line": 1, "column": 1 }, "end": { "line": 20, "column": 1 } } } TypeError: Type 'string' is not assignable to type 'number'. [tupleAssignability10.ts:18:20]