babel/eslint/babel-eslint-plugin/test/rules/new-cap.js

/**
 * @fileoverview Tests for new-cap rule.
 * @author Nicholas C. Zakas
 */

var rule = require("../../src/rules/new-cap"),
  RuleTester = require("../helpers/RuleTester");

var ruleTester = new RuleTester();
ruleTester.run("babel/new-cap", rule, {
  valid: [
    // Original test cases.
    "var x = new Constructor();",
    "var x = new a.b.Constructor();",
    "var x = new a.b['Constructor']();",
    "var x = new a.b[Constructor]();",
    "var x = new a.b[constructor]();",
    "var x = new function(){};",
    "var x = new _;",
    "var x = new $;",
    "var x = new Σ;",
    "var x = new _x;",
    "var x = new $x;",
    "var x = new this;",
    "var x = Array(42)",
    "var x = Boolean(42)",
    "var x = Date(42)",
    "var x = Date.UTC(2000, 0)",
    "var x = Error('error')",
    "var x = Function('return 0')",
    "var x = Number(42)",
    "var x = Object(null)",
    "var x = RegExp(42)",
    "var x = String(42)",
    "var x = Symbol('symbol')",
    "var x = _();",
    "var x = $();",
    { code: "var x = Foo(42)", options: [{ capIsNew: false }] },
    { code: "var x = bar.Foo(42)", options: [{ capIsNew: false }] },
    { code: "var x = Foo.bar(42)", options: [{ capIsNew: false }] },
    "var x = bar[Foo](42)",
    { code: "var x = bar['Foo'](42)", options: [{ capIsNew: false }] },
    "var x = Foo.bar(42)",
    { code: "var x = new foo(42)", options: [{ newIsCap: false }] },
    "var o = { 1: function() {} }; o[1]();",
    "var o = { 1: function() {} }; new o[1]();",
    {
      code: "var x = Foo(42);",
      options: [{ capIsNew: true, capIsNewExceptions: ["Foo"] }],
    },
    {
      code: "var x = Foo(42);",
      options: [{ capIsNewExceptionPattern: "^Foo" }],
    },
    {
      code: "var x = new foo(42);",
      options: [{ newIsCap: true, newIsCapExceptions: ["foo"] }],
    },
    {
      code: "var x = new foo(42);",
      options: [{ newIsCapExceptionPattern: "^foo" }],
    },
    { code: "var x = Object(42);", options: [{ capIsNewExceptions: ["Foo"] }] },

    {
      code: "var x = Foo.Bar(42);",
      options: [{ capIsNewExceptions: ["Bar"] }],
    },
    {
      code: "var x = Foo.Bar(42);",
      options: [{ capIsNewExceptions: ["Foo.Bar"] }],
    },

    {
      code: "var x = Foo.Bar(42);",
      options: [{ capIsNewExceptionPattern: "^Foo\\.." }],
    },
    {
      code: "var x = new foo.bar(42);",
      options: [{ newIsCapExceptions: ["bar"] }],
    },
    {
      code: "var x = new foo.bar(42);",
      options: [{ newIsCapExceptions: ["foo.bar"] }],
    },

    {
      code: "var x = new foo.bar(42);",
      options: [{ newIsCapExceptionPattern: "^foo\\.." }],
    },
    { code: "var x = new foo.bar(42);", options: [{ properties: false }] },
    { code: "var x = Foo.bar(42);", options: [{ properties: false }] },
    {
      code: "var x = foo.Bar(42);",
      options: [{ capIsNew: false, properties: false }],
    },

    // Babel-specific test cases.
    { code: "@MyDecorator(123) class MyClass{}", parser: "babel-eslint" },
  ],
  invalid: [
    {
      code: "var x = new c();",
      errors: [
        {
          message:
            "A constructor name should not start with a lowercase letter.",
          type: "NewExpression",
        },
      ],
    },
    {
      code: "var x = new φ;",
      errors: [
        {
          message:
            "A constructor name should not start with a lowercase letter.",
          type: "NewExpression",
        },
      ],
    },
    {
      code: "var x = new a.b.c;",
      errors: [
        {
          message:
            "A constructor name should not start with a lowercase letter.",
          type: "NewExpression",
        },
      ],
    },
    {
      code: "var x = new a.b['c'];",
      errors: [
        {
          message:
            "A constructor name should not start with a lowercase letter.",
          type: "NewExpression",
        },
      ],
    },
    {
      code: "var b = Foo();",
      errors: [
        {
          message:
            "A function with a name starting with an uppercase letter should only be used as a constructor.",
          type: "CallExpression",
        },
      ],
    },
    {
      code: "var b = a.Foo();",
      errors: [
        {
          message:
            "A function with a name starting with an uppercase letter should only be used as a constructor.",
          type: "CallExpression",
        },
      ],
    },
    {
      code: "var b = a['Foo']();",
      errors: [
        {
          message:
            "A function with a name starting with an uppercase letter should only be used as a constructor.",
          type: "CallExpression",
        },
      ],
    },
    {
      code: "var b = a.Date.UTC();",
      errors: [
        {
          message:
            "A function with a name starting with an uppercase letter should only be used as a constructor.",
          type: "CallExpression",
        },
      ],
    },
    {
      code: "var b = UTC();",
      errors: [
        {
          message:
            "A function with a name starting with an uppercase letter should only be used as a constructor.",
          type: "CallExpression",
        },
      ],
    },
    {
      code: "var a = B.C();",
      errors: [
        {
          message:
            "A function with a name starting with an uppercase letter should only be used as a constructor.",
          type: "CallExpression",
          line: 1,
          column: 11,
        },
      ],
    },
    {
      code: "var a = B\n.C();",
      errors: [
        {
          message:
            "A function with a name starting with an uppercase letter should only be used as a constructor.",
          type: "CallExpression",
          line: 2,
          column: 2,
        },
      ],
    },
    {
      code: "var a = new B.c();",
      errors: [
        {
          message:
            "A constructor name should not start with a lowercase letter.",
          type: "NewExpression",
          line: 1,
          column: 15,
        },
      ],
    },
    {
      code: "var a = new B.\nc();",
      errors: [
        {
          message:
            "A constructor name should not start with a lowercase letter.",
          type: "NewExpression",
          line: 2,
          column: 1,
        },
      ],
    },
    {
      code: "var a = new c();",
      errors: [
        {
          message:
            "A constructor name should not start with a lowercase letter.",
          type: "NewExpression",
          line: 1,
          column: 13,
        },
      ],
    },

    {
      code: "var x = Foo.Bar(42);",
      options: [{ capIsNewExceptions: ["Foo"] }],
      errors: [
        {
          type: "CallExpression",
          message:
            "A function with a name starting with an uppercase letter should only be used as a constructor.",
        },
      ],
    },
    {
      code: "var x = Bar.Foo(42);",

      options: [{ capIsNewExceptionPattern: "^Foo\\.." }],
      errors: [
        {
          type: "CallExpression",
          message:
            "A function with a name starting with an uppercase letter should only be used as a constructor.",
        },
      ],
    },
    {
      code: "var x = new foo.bar(42);",
      options: [{ newIsCapExceptions: ["foo"] }],
      errors: [
        {
          type: "NewExpression",
          message:
            "A constructor name should not start with a lowercase letter.",
        },
      ],
    },
    {
      code: "var x = new bar.foo(42);",

      options: [{ newIsCapExceptionPattern: "^foo\\.." }],
      errors: [
        {
          type: "NewExpression",
          message:
            "A constructor name should not start with a lowercase letter.",
        },
      ],
    },
  ],
});