eslint/tests/lib/rules/consistent-return.js

   1 /**
   2  * @fileoverview Tests for consistent-return rule.
   3  * @author Raphael Pigulla
   4  */
   5
   6 "use strict";
   7
   8 //------------------------------------------------------------------------------
   9 // Requirements
  10 //------------------------------------------------------------------------------
  11 const rule = require("../../../lib/rules/consistent-return"),
  12     { RuleTester } = require("../../../lib/rule-tester");
  13
  14 //------------------------------------------------------------------------------
  15 // Tests
  16 //------------------------------------------------------------------------------
  17
  18 const ruleTester = new RuleTester();
  19
  20 ruleTester.run("consistent-return", rule, {
  21
  22     valid: [
  23         "function foo() { return; }",
  24         "function foo() { if (true) return; }",
  25         "function foo() { if (true) return; else return; }",
  26         "function foo() { if (true) return true; else return false; }",
  27         "f(function() { return; })",
  28         "f(function() { if (true) return; })",
  29         "f(function() { if (true) return; else return; })",
  30         "f(function() { if (true) return true; else return false; })",
  31         "function foo() { function bar() { return true; } return; }",
  32         "function foo() { function bar() { return; } return false; }",
  33         "function Foo() { if (!(this instanceof Foo)) return new Foo(); }",
  34         { code: "function foo() { if (true) return; else return undefined; }", options: [{ treatUndefinedAsUnspecified: true }] },
  35         { code: "function foo() { if (true) return; else return void 0; }", options: [{ treatUndefinedAsUnspecified: true }] },
  36         { code: "function foo() { if (true) return undefined; else return; }", options: [{ treatUndefinedAsUnspecified: true }] },
  37         { code: "function foo() { if (true) return undefined; else return void 0; }", options: [{ treatUndefinedAsUnspecified: true }] },
  38         { code: "function foo() { if (true) return void 0; else return; }", options: [{ treatUndefinedAsUnspecified: true }] },
  39         { code: "function foo() { if (true) return void 0; else return undefined; }", options: [{ treatUndefinedAsUnspecified: true }] },
  40         { code: "var x = () => {  return {}; };", parserOptions: { ecmaVersion: 6 } },
  41         { code: "if (true) { return 1; } return 0;", parserOptions: { ecmaVersion: 6, ecmaFeatures: { globalReturn: true } } },
  42
  43         // https://github.com/eslint/eslint/issues/7790
  44         { code: "class Foo { constructor() { if (true) return foo; } }", parserOptions: { ecmaVersion: 6 } },
  45         { code: "var Foo = class { constructor() { if (true) return foo; } }", parserOptions: { ecmaVersion: 6 } }
  46     ],
  47
  48     invalid: [
  49         {
  50             code: "function foo() { if (true) return true; else return; }",
  51             errors: [
  52                 {
  53                     messageId: "missingReturnValue",
  54                     data: { name: "Function 'foo'" },
  55                     type: "ReturnStatement"
  56                 }
  57             ]
  58         },
  59         {
  60             code: "var foo = () => { if (true) return true; else return; }",
  61             parserOptions: { ecmaVersion: 6 },
  62             errors: [
  63                 {
  64                     messageId: "missingReturnValue",
  65                     data: { name: "Arrow function" },
  66                     type: "ReturnStatement"
  67                 }
  68             ]
  69         },
  70         {
  71             code: "function foo() { if (true) return; else return false; }",
  72             errors: [
  73                 {
  74                     messageId: "unexpectedReturnValue",
  75                     data: { name: "Function 'foo'" },
  76                     type: "ReturnStatement"
  77                 }
  78             ]
  79         },
  80         {
  81             code: "f(function() { if (true) return true; else return; })",
  82             errors: [
  83                 {
  84                     messageId: "missingReturnValue",
  85                     data: { name: "Function" },
  86                     type: "ReturnStatement"
  87                 }
  88             ]
  89         },
  90         {
  91             code: "f(function() { if (true) return; else return false; })",
  92             errors: [
  93                 {
  94                     messageId: "unexpectedReturnValue",
  95                     data: { name: "Function" },
  96                     type: "ReturnStatement"
  97                 }
  98             ]
  99         },
 100         {
 101             code: "f(a => { if (true) return; else return false; })",
 102             parserOptions: { ecmaVersion: 6 },
 103             errors: [
 104                 {
 105                     messageId: "unexpectedReturnValue",
 106                     data: { name: "Arrow function" },
 107                     type: "ReturnStatement"
 108                 }
 109             ]
 110         },
 111         {
 112             code: "function foo() { if (true) return true; return undefined; }",
 113             options: [{ treatUndefinedAsUnspecified: true }],
 114             errors: [
 115                 {
 116                     messageId: "missingReturnValue",
 117                     data: { name: "Function 'foo'" },
 118                     type: "ReturnStatement",
 119                     column: 41
 120                 }
 121             ]
 122         },
 123         {
 124             code: "function foo() { if (true) return true; return void 0; }",
 125             options: [{ treatUndefinedAsUnspecified: true }],
 126             errors: [
 127                 {
 128                     messageId: "missingReturnValue",
 129                     data: { name: "Function 'foo'" },
 130                     type: "ReturnStatement",
 131                     column: 41
 132                 }
 133             ]
 134         },
 135         {
 136             code: "function foo() { if (true) return undefined; return true; }",
 137             options: [{ treatUndefinedAsUnspecified: true }],
 138             errors: [
 139                 {
 140                     messageId: "unexpectedReturnValue",
 141                     data: { name: "Function 'foo'" },
 142                     type: "ReturnStatement",
 143                     column: 46
 144                 }
 145             ]
 146         },
 147         {
 148             code: "function foo() { if (true) return void 0; return true; }",
 149             options: [{ treatUndefinedAsUnspecified: true }],
 150             errors: [
 151                 {
 152                     messageId: "unexpectedReturnValue",
 153                     data: { name: "Function 'foo'" },
 154                     type: "ReturnStatement",
 155                     column: 43
 156                 }
 157             ]
 158         },
 159         {
 160             code: "if (true) { return 1; } return;",
 161             parserOptions: { ecmaFeatures: { globalReturn: true } },
 162             errors: [
 163                 {
 164                     messageId: "missingReturnValue",
 165                     data: { name: "Program" },
 166                     type: "ReturnStatement"
 167                 }
 168             ]
 169         },
 170         {
 171             code: "function foo() { if (a) return true; }",
 172             errors: [
 173                 {
 174                     messageId: "missingReturn",
 175                     data: { name: "function 'foo'" },
 176                     type: "FunctionDeclaration",
 177                     column: 10
 178                 }
 179             ]
 180         },
 181         {
 182             code: "function _foo() { if (a) return true; }",
 183             errors: [
 184                 {
 185                     messageId: "missingReturn",
 186                     data: { name: "function '_foo'" },
 187                     type: "FunctionDeclaration",
 188                     column: 10
 189                 }
 190             ]
 191         },
 192         {
 193             code: "f(function foo() { if (a) return true; });",
 194             errors: [
 195                 {
 196                     messageId: "missingReturn",
 197                     data: { name: "function 'foo'" },
 198                     type: "FunctionExpression",
 199                     column: 12
 200                 }
 201             ]
 202         },
 203         {
 204             code: "f(function() { if (a) return true; });",
 205             errors: [
 206                 {
 207                     messageId: "missingReturn",
 208                     data: { name: "function" },
 209                     type: "FunctionExpression",
 210                     column: 3
 211                 }
 212             ]
 213         },
 214         {
 215             code: "f(() => { if (a) return true; });",
 216             parserOptions: { ecmaVersion: 6 },
 217             errors: [
 218                 {
 219                     messageId: "missingReturn",
 220                     data: { name: "arrow function" },
 221                     type: "ArrowFunctionExpression",
 222                     column: 6
 223                 }
 224             ]
 225         },
 226         {
 227             code: "var obj = {foo() { if (a) return true; }};",
 228             parserOptions: { ecmaVersion: 6 },
 229             errors: [
 230                 {
 231                     messageId: "missingReturn",
 232                     data: { name: "method 'foo'" },
 233                     type: "FunctionExpression",
 234                     column: 12
 235                 }
 236             ]
 237         },
 238         {
 239             code: "class A {foo() { if (a) return true; }};",
 240             parserOptions: { ecmaVersion: 6 },
 241             errors: [
 242                 {
 243                     messageId: "missingReturn",
 244                     data: { name: "method 'foo'" },
 245                     type: "FunctionExpression",
 246                     column: 10
 247                 }
 248             ]
 249         },
 250         {
 251             code: "if (a) return true;",
 252             parserOptions: { ecmaFeatures: { globalReturn: true } },
 253             errors: [
 254                 {
 255                     messageId: "missingReturn",
 256                     data: { name: "program" },
 257                     type: "Program",
 258                     column: 1
 259                 }
 260             ]
 261         },
 262         {
 263             code: "class A { CapitalizedFunction() { if (a) return true; } }",
 264             parserOptions: { ecmaVersion: 6 },
 265             errors: [
 266                 {
 267                     messageId: "missingReturn",
 268                     data: { name: "method 'CapitalizedFunction'" },
 269                     type: "FunctionExpression",
 270                     column: 11
 271                 }
 272             ]
 273         },
 274         {
 275             code: "({ constructor() { if (a) return true; } });",
 276             parserOptions: { ecmaVersion: 6 },
 277             errors: [
 278                 {
 279                     messageId: "missingReturn",
 280                     data: { name: "method 'constructor'" },
 281                     type: "FunctionExpression",
 282                     column: 4
 283                 }
 284             ]
 285         }
 286     ]
 287 });