restrict-plus-operands.test.ts

import rule from '../../src/rules/restrict-plus-operands';
import { RuleTester, getFixturesRootDir } from '../RuleTester';

const rootPath = getFixturesRootDir();

const ruleTester = new RuleTester({
  parser: '@typescript-eslint/parser',
  parserOptions: {
    tsconfigRootDir: rootPath,
    project: './tsconfig.json',
  },
});

ruleTester.run('restrict-plus-operands', rule, {
  valid: [
    `var x = 5;`,
    `var y = "10";`,
    `var z = 8.2;`,
    `var w = "6.5";`,
    `var foo = 5 + 10;`,
    `var foo = "5.5" + "10";`,
    `var foo = parseInt("5.5", 10) + 10;`,
    `var foo = parseFloat("5.5", 10) + 10;`,
    `var foo = 1n + 1n;`,
    `var foo = BigInt(1) + 1n`,
    `var foo = 1n; foo + 2n`,
    `
function test(s: string, n: number) : number { return 2; }
var foo = test("5.5", 10) + 10;
    `,
    `
var x = 5;
var z = 8.2;
var foo = x + z;
    `,
    `
var w = "6.5";
var y = "10";
var foo = y + w;
    `,
    'var foo = 1 + 1;',
    "var foo = '1' + '1';",
    `
var pair: { first: number, second: string } = { first: 5, second: "10" };
var foo = pair.first + 10;
    `,
    `
var pair: { first: number, second: string } = { first: 5, second: "10" };
var foo = pair.first + (10 as number);
    `,
    `
var pair: { first: number, second: string } = { first: 5, second: "10" };
var foo = "5.5" + pair.second;
    `,
    `
var pair: { first: number, second: string } = { first: 5, second: "10" };
var foo = ("5.5" as string) + pair.second;
    `,
    `const foo = 'hello' + (someBoolean ? 'a' : 'b') + (() => someBoolean ? 'c' : 'd')() + 'e';`,
    `const balls = true;`,
    `balls === true;`,
    // https://github.com/typescript-eslint/typescript-eslint/issues/230
    `
function foo<T extends string>(a: T) {
    return a + "";
}
    `,
    `
function foo<T extends "a" | "b">(a: T) {
    return a + "";
}
    `,
    `
function foo<T extends number>(a: T) {
    return a + 1;
}
    `,
    `
function foo<T extends 1>(a: T) {
    return a + 1;
}
    `,
    {
      code: `
let foo: number = 0;
foo += 1;
    `,
      options: [
        {
          checkCompoundAssignments: false,
        },
      ],
    },
    {
      code: `
let foo: number = 0;
foo += "string";
    `,
      options: [
        {
          checkCompoundAssignments: false,
        },
      ],
    },
  ],
  invalid: [
    {
      code: "var foo = '1' + 1;",
      errors: [
        {
          messageId: 'notStrings',
          line: 1,
          column: 11,
        },
      ],
    },
    {
      code: 'var foo = [] + {};',
      errors: [
        {
          messageId: 'notNumbers',
          line: 1,
          column: 11,
        },
      ],
    },
    {
      code: `var foo = 5 + "10";`,
      errors: [
        {
          messageId: 'notStrings',
          line: 1,
          column: 11,
        },
      ],
    },
    {
      code: `var foo = [] + 5;`,
      errors: [
        {
          messageId: 'notNumbers',
          line: 1,
          column: 11,
        },
      ],
    },
    {
      code: `var foo = [] + {};`,
      errors: [
        {
          messageId: 'notNumbers',
          line: 1,
          column: 11,
        },
      ],
    },
    {
      code: `var foo = [] + [];`,
      errors: [
        {
          messageId: 'notNumbers',
          line: 1,
          column: 11,
        },
      ],
    },
    {
      code: `var foo = 5 + [];`,
      errors: [
        {
          messageId: 'notNumbers',
          line: 1,
          column: 11,
        },
      ],
    },
    {
      code: `var foo = "5" + {};`,
      errors: [
        {
          messageId: 'notStrings',
          line: 1,
          column: 11,
        },
      ],
    },
    {
      code: `var foo = 5.5 + "5";`,
      errors: [
        {
          messageId: 'notStrings',
          line: 1,
          column: 11,
        },
      ],
    },
    {
      code: `var foo = "5.5" + 5;`,
      errors: [
        {
          messageId: 'notStrings',
          line: 1,
          column: 11,
        },
      ],
    },
    {
      code: `
var x = 5;
var y = "10";
var foo = x + y;
            `,
      errors: [
        {
          messageId: 'notStrings',
          line: 4,
          column: 11,
        },
      ],
    },
    {
      code: `
var x = 5;
var y = "10";
var foo = y + x;
            `,
      errors: [
        {
          messageId: 'notStrings',
          line: 4,
          column: 11,
        },
      ],
    },
    {
      code: `
var x = 5;
var foo = x + {};
            `,
      errors: [
        {
          messageId: 'notNumbers',
          line: 3,
          column: 11,
        },
      ],
    },
    {
      code: `
var y = "10";
var foo = [] + y;
            `,
      errors: [
        {
          messageId: 'notStrings',
          line: 3,
          column: 11,
        },
      ],
    },
    {
      code: `
var pair: { first: number, second: string } = { first: 5, second: "10" };
var foo = pair.first + "10";
            `,
      errors: [
        {
          messageId: 'notStrings',
          line: 3,
          column: 11,
        },
      ],
    },
    {
      code: `
var pair: { first: number, second: string } = { first: 5, second: "10" };
var foo = 5 + pair.second;
            `,
      errors: [
        {
          messageId: 'notStrings',
          line: 3,
          column: 11,
        },
      ],
    },
    {
      code: `var foo = parseInt("5.5", 10) + "10";`,
      errors: [
        {
          messageId: 'notStrings',
          line: 1,
          column: 11,
        },
      ],
    },
    {
      code: `
var pair = { first: 5, second: "10" };
var foo = pair + pair;
            `,
      errors: [
        {
          messageId: 'notNumbers',
          line: 3,
          column: 11,
        },
      ],
    },
    {
      code: `var foo = 1n + 1`,
      errors: [
        {
          messageId: 'notBigInts',
          line: 1,
          column: 11,
        },
      ],
    },
    {
      code: `var foo = 1 + 1n`,
      errors: [
        {
          messageId: 'notBigInts',
          line: 1,
          column: 11,
        },
      ],
    },
    {
      code: `var foo = 1n; foo + 1`,
      errors: [
        {
          messageId: 'notBigInts',
          line: 1,
          column: 15,
        },
      ],
    },
    {
      code: `var foo = 1; foo + 1n`,
      errors: [
        {
          messageId: 'notBigInts',
          line: 1,
          column: 14,
        },
      ],
    },
    // https://github.com/typescript-eslint/typescript-eslint/issues/230
    {
      code: `
function foo<T extends string>(a: T) {
    return a + 1;
}
      `,
      errors: [
        {
          messageId: 'notStrings',
          line: 3,
          column: 12,
        },
      ],
    },
    {
      code: `
function foo<T extends "a" | "b">(a: T) {
    return a + 1;
}
      `,
      errors: [
        {
          messageId: 'notStrings',
          line: 3,
          column: 12,
        },
      ],
    },
    {
      code: `
function foo<T extends number>(a: T) {
    return a + "";
}
      `,
      errors: [
        {
          messageId: 'notStrings',
          line: 3,
          column: 12,
        },
      ],
    },
    {
      code: `
function foo<T extends 1>(a: T) {
    return a + "";
}
      `,
      errors: [
        {
          messageId: 'notStrings',
          line: 3,
          column: 12,
        },
      ],
    },
    {
      code: `
let foo: string | undefined;
foo += "some data";
      `,
      options: [
        {
          checkCompoundAssignments: true,
        },
      ],
      errors: [
        {
          messageId: 'notStrings',
          line: 3,
          column: 1,
        },
      ],
    },
    {
      code: `
let foo = '';
foo += 0;
      `,
      options: [
        {
          checkCompoundAssignments: true,
        },
      ],
      errors: [
        {
          messageId: 'notStrings',
          line: 3,
          column: 1,
        },
      ],
    },
  ],
});