#no-base-to-string

#Configuration

import { defineConfig, ts } from '@rslint/core';

export default defineConfig([
  ts.configs.recommended,
  {
    rules: {
      '@typescript-eslint/no-base-to-string': 'error',
    },
  },
]);

#Rule Details

Require .toString() and .toLocaleString() to only be called on objects which provide useful information when stringified. JavaScript calls toString() implicitly in string contexts such as template literals and string concatenation. The default Object.prototype.toString() returns "[object Object]", which is rarely useful.

This rule uses type information to detect when a value will use the base Object.prototype.toString() and flags string concatenation, template literals, explicit .toString()/.toLocaleString() calls, String() calls, and .join() on arrays containing such types.

Examples of incorrect code for this rule:

class MyClass {}
const obj = new MyClass();

`Value: ${obj}`;
'' + obj;
obj.toString();
[obj].join(',');

Examples of correct code for this rule:

`Value: ${'str'}`;
'' + 42;

class MyClass {
  toString() {
    return 'MyClass';
  }
}
`Value: ${new MyClass()}`;

#Original Documentation

• typescript-eslint no-base-to-string