eslint/tests/lib/rules/max-lines-per-function.js

   1 /**
   2  * @fileoverview Tests for max-lines-per-function rule.
   3  * @author Pete Ward <peteward44@gmail.com>
   4  */
   5 "use strict";
   6
   7 //------------------------------------------------------------------------------
   8 // Requirements
   9 //------------------------------------------------------------------------------
  10
  11 const rule = require("../../../lib/rules/max-lines-per-function");
  12 const { RuleTester } = require("../../../lib/rule-tester");
  13
  14 //------------------------------------------------------------------------------
  15 // Tests
  16 //------------------------------------------------------------------------------
  17
  18 const ruleTester = new RuleTester({ parserOptions: { ecmaVersion: 6 } });
  19
  20 ruleTester.run("max-lines-per-function", rule, {
  21     valid: [
  22
  23         // Test code in global scope doesn't count
  24         {
  25             code: "var x = 5;\nvar x = 2;\n",
  26             options: [1]
  27         },
  28
  29         // Test single line standalone function
  30         {
  31             code: "function name() {}",
  32             options: [1]
  33         },
  34
  35         // Test standalone function with lines of code
  36         {
  37             code: "function name() {\nvar x = 5;\nvar x = 2;\n}",
  38             options: [4]
  39         },
  40
  41         // Test inline arrow function
  42         {
  43             code: "const bar = () => 2",
  44             options: [1]
  45         },
  46
  47         // Test arrow function
  48         {
  49             code: "const bar = () => {\nconst x = 2 + 1;\nreturn x;\n}",
  50             options: [4]
  51         },
  52
  53         // skipBlankLines: false with simple standalone function
  54         {
  55             code: "function name() {\nvar x = 5;\n\t\n \n\nvar x = 2;\n}",
  56             options: [{ max: 7, skipComments: false, skipBlankLines: false }]
  57         },
  58
  59         // skipBlankLines: true with simple standalone function
  60         {
  61             code: "function name() {\nvar x = 5;\n\t\n \n\nvar x = 2;\n}",
  62             options: [{ max: 4, skipComments: false, skipBlankLines: true }]
  63         },
  64
  65         // skipComments: true with an individual single line comment
  66         {
  67             code: "function name() {\nvar x = 5;\nvar x = 2; // end of line comment\n}",
  68             options: [{ max: 4, skipComments: true, skipBlankLines: false }]
  69         },
  70
  71         // skipComments: true with an individual single line comment
  72         {
  73             code: "function name() {\nvar x = 5;\n// a comment on it's own line\nvar x = 2; // end of line comment\n}",
  74             options: [{ max: 4, skipComments: true, skipBlankLines: false }]
  75         },
  76
  77         // skipComments: true with single line comments
  78         {
  79             code: "function name() {\nvar x = 5;\n// a comment on it's own line\n// and another line comment\nvar x = 2; // end of line comment\n}",
  80             options: [{ max: 4, skipComments: true, skipBlankLines: false }]
  81         },
  82
  83         // skipComments: true test with multiple different comment types
  84         {
  85             code: "function name() {\nvar x = 5;\n/* a \n multi \n line \n comment \n*/\n\nvar x = 2; // end of line comment\n}",
  86             options: [{ max: 5, skipComments: true, skipBlankLines: false }]
  87         },
  88
  89         // skipComments: true with multiple different comment types, including trailing and leading whitespace
  90         {
  91             code: "function name() {\nvar x = 5;\n\t/* a comment with leading whitespace */\n/* a comment with trailing whitespace */\t\t\n\t/* a comment with trailing and leading whitespace */\t\t\n/* a \n multi \n line \n comment \n*/\t\t\n\nvar x = 2; // end of line comment\n}",
  92             options: [{ max: 5, skipComments: true, skipBlankLines: false }]
  93         },
  94
  95         // Multiple params on separate lines test
  96         {
  97             code: `function foo(
  98     aaa = 1,
  99     bbb = 2,
 100     ccc = 3
 101 ) {
 102     return aaa + bbb + ccc
 103 }`,
 104             options: [{ max: 7, skipComments: true, skipBlankLines: false }]
 105         },
 106
 107         // IIFE validity test
 108         {
 109             code: `(
 110 function
 111 ()
 112 {
 113 }
 114 )
 115 ()`,
 116             options: [{ max: 4, skipComments: true, skipBlankLines: false, IIFEs: true }]
 117         },
 118
 119         // Nested function validity test
 120         {
 121             code: `function parent() {
 122 var x = 0;
 123 function nested() {
 124     var y = 0;
 125     x = 2;
 126 }
 127 if ( x === y ) {
 128     x++;
 129 }
 130 }`,
 131             options: [{ max: 10, skipComments: true, skipBlankLines: false }]
 132         },
 133
 134         // Class method validity test
 135         {
 136             code: `class foo {
 137     method() {
 138         let y = 10;
 139         let x = 20;
 140         return y + x;
 141     }
 142 }`,
 143             options: [{ max: 5, skipComments: true, skipBlankLines: false }]
 144         },
 145
 146         // IIFEs should be recognised if IIFEs: true
 147         {
 148             code: `(function(){
 149     let x = 0;
 150     let y = 0;
 151     let z = x + y;
 152     let foo = {};
 153     return bar;
 154 }());`,
 155             options: [{ max: 7, skipComments: true, skipBlankLines: false, IIFEs: true }]
 156         },
 157
 158         // IIFEs should not be recognised if IIFEs: false
 159         {
 160             code: `(function(){
 161     let x = 0;
 162     let y = 0;
 163     let z = x + y;
 164     let foo = {};
 165     return bar;
 166 }());`,
 167             options: [{ max: 2, skipComments: true, skipBlankLines: false, IIFEs: false }]
 168         },
 169
 170         // Arrow IIFEs should be recognised if IIFEs: true
 171         {
 172             code: `(() => {
 173     let x = 0;
 174     let y = 0;
 175     let z = x + y;
 176     let foo = {};
 177     return bar;
 178 })();`,
 179             options: [{ max: 7, skipComments: true, skipBlankLines: false, IIFEs: true }]
 180         },
 181
 182         // Arrow IIFEs should not be recognised if IIFEs: false
 183         {
 184             code: `(() => {
 185     let x = 0;
 186     let y = 0;
 187     let z = x + y;
 188     let foo = {};
 189     return bar;
 190 })();`,
 191             options: [{ max: 2, skipComments: true, skipBlankLines: false, IIFEs: false }]
 192         }
 193     ],
 194
 195     invalid: [
 196
 197         // Test simple standalone function is recognised
 198         {
 199             code: "function name() {\n}",
 200             options: [1],
 201             errors: [
 202                 { messageId: "exceed", data: { name: "Function 'name'", lineCount: 2, maxLines: 1 } }
 203             ]
 204         },
 205
 206         // Test anonymous function assigned to variable is recognised
 207         {
 208             code: "var func = function() {\n}",
 209             options: [1],
 210             errors: [
 211                 { messageId: "exceed", data: { name: "Function", lineCount: 2, maxLines: 1 } }
 212             ]
 213         },
 214
 215         // Test arrow functions are recognised
 216         {
 217             code: "const bar = () => {\nconst x = 2 + 1;\nreturn x;\n}",
 218             options: [3],
 219             errors: [
 220                 { messageId: "exceed", data: { name: "Arrow function", lineCount: 4, maxLines: 3 } }
 221             ]
 222         },
 223
 224         // Test inline arrow functions are recognised
 225         {
 226             code: "const bar = () =>\n 2",
 227             options: [1],
 228             errors: [
 229                 { messageId: "exceed", data: { name: "Arrow function", lineCount: 2, maxLines: 1 } }
 230             ]
 231         },
 232
 233         // Test that option defaults work as expected
 234         {
 235             code: `() => {${"foo\n".repeat(60)}}`,
 236             options: [{}],
 237             errors: [
 238                 { messageId: "exceed", data: { name: "Arrow function", lineCount: 61, maxLines: 50 } }
 239             ]
 240         },
 241
 242         // Test skipBlankLines: false
 243         {
 244             code: "function name() {\nvar x = 5;\n\t\n \n\nvar x = 2;\n}",
 245             options: [{ max: 6, skipComments: false, skipBlankLines: false }],
 246             errors: [
 247                 { messageId: "exceed", data: { name: "Function 'name'", lineCount: 7, maxLines: 6 } }
 248             ]
 249         },
 250
 251         // Test skipBlankLines: false with CRLF line endings
 252         {
 253             code: "function name() {\r\nvar x = 5;\r\n\t\r\n \r\n\r\nvar x = 2;\r\n}",
 254             options: [{ max: 6, skipComments: true, skipBlankLines: false }],
 255             errors: [
 256                 { messageId: "exceed", data: { name: "Function 'name'", lineCount: 7, maxLines: 6 } }
 257             ]
 258         },
 259
 260         // Test skipBlankLines: true
 261         {
 262             code: "function name() {\nvar x = 5;\n\t\n \n\nvar x = 2;\n}",
 263             options: [{ max: 2, skipComments: true, skipBlankLines: true }],
 264             errors: [
 265                 { messageId: "exceed", data: { name: "Function 'name'", lineCount: 4, maxLines: 2 } }
 266             ]
 267         },
 268
 269         // Test skipBlankLines: true with CRLF line endings
 270         {
 271             code: "function name() {\r\nvar x = 5;\r\n\t\r\n \r\n\r\nvar x = 2;\r\n}",
 272             options: [{ max: 2, skipComments: true, skipBlankLines: true }],
 273             errors: [
 274                 { messageId: "exceed", data: { name: "Function 'name'", lineCount: 4, maxLines: 2 } }
 275             ]
 276         },
 277
 278         // Test skipComments: true and skipBlankLines: false for multiple types of comment
 279         {
 280             code: "function name() { // end of line comment\nvar x = 5; /* mid line comment */\n\t// single line comment taking up whole line\n\t\n \n\nvar x = 2;\n}",
 281             options: [{ max: 6, skipComments: true, skipBlankLines: false }],
 282             errors: [
 283                 { messageId: "exceed", data: { name: "Function 'name'", lineCount: 7, maxLines: 6 } }
 284             ]
 285         },
 286
 287         // Test skipComments: true and skipBlankLines: true for multiple types of comment
 288         {
 289             code: "function name() { // end of line comment\nvar x = 5; /* mid line comment */\n\t// single line comment taking up whole line\n\t\n \n\nvar x = 2;\n}",
 290             options: [{ max: 1, skipComments: true, skipBlankLines: true }],
 291             errors: [
 292                 { messageId: "exceed", data: { name: "Function 'name'", lineCount: 4, maxLines: 1 } }
 293             ]
 294         },
 295
 296         // Test skipComments: false and skipBlankLines: true for multiple types of comment
 297         {
 298             code: "function name() { // end of line comment\nvar x = 5; /* mid line comment */\n\t// single line comment taking up whole line\n\t\n \n\nvar x = 2;\n}",
 299             options: [{ max: 1, skipComments: false, skipBlankLines: true }],
 300             errors: [
 301                 { messageId: "exceed", data: { name: "Function 'name'", lineCount: 5, maxLines: 1 } }
 302             ]
 303         },
 304
 305         // Test simple standalone function with params on separate lines
 306         {
 307             code: `function foo(
 308     aaa = 1,
 309     bbb = 2,
 310     ccc = 3
 311 ) {
 312     return aaa + bbb + ccc
 313 }`,
 314             options: [{ max: 2, skipComments: true, skipBlankLines: false }],
 315             errors: [
 316                 { messageId: "exceed", data: { name: "Function 'foo'", lineCount: 7, maxLines: 2 } }
 317             ]
 318         },
 319
 320         // Test IIFE "function" keyword is included in the count
 321         {
 322             code: `(
 323 function
 324 ()
 325 {
 326 }
 327 )
 328 ()`,
 329             options: [{ max: 2, skipComments: true, skipBlankLines: false, IIFEs: true }],
 330             errors: [
 331                 { messageId: "exceed", data: { name: "Function", lineCount: 4, maxLines: 2 } }
 332             ]
 333         },
 334
 335         // Test nested functions are included in it's parent's function count.
 336         {
 337             code: `function parent() {
 338 var x = 0;
 339 function nested() {
 340     var y = 0;
 341     x = 2;
 342 }
 343 if ( x === y ) {
 344     x++;
 345 }
 346 }`,
 347             options: [{ max: 9, skipComments: true, skipBlankLines: false }],
 348             errors: [
 349                 { messageId: "exceed", data: { name: "Function 'parent'", lineCount: 10, maxLines: 9 } }
 350             ]
 351         },
 352
 353         // Test nested functions are included in it's parent's function count.
 354         {
 355             code: `function parent() {
 356 var x = 0;
 357 function nested() {
 358     var y = 0;
 359     x = 2;
 360 }
 361 if ( x === y ) {
 362     x++;
 363 }
 364 }`,
 365             options: [{ max: 2, skipComments: true, skipBlankLines: false }],
 366             errors: [
 367                 { messageId: "exceed", data: { name: "Function 'parent'", lineCount: 10, maxLines: 2 } },
 368                 { messageId: "exceed", data: { name: "Function 'nested'", lineCount: 4, maxLines: 2 } }
 369             ]
 370         },
 371
 372         // Test regular methods are recognised
 373         {
 374             code: `class foo {
 375     method() {
 376         let y = 10;
 377         let x = 20;
 378         return y + x;
 379     }
 380 }`,
 381             options: [{ max: 2, skipComments: true, skipBlankLines: false }],
 382             errors: [
 383                 { messageId: "exceed", data: { name: "Method 'method'", lineCount: 5, maxLines: 2 } }
 384             ]
 385         },
 386
 387         // Test static methods are recognised
 388         {
 389             code: `class A {
 390     static
 391     foo
 392     (a) {
 393         return a
 394     }
 395 }`,
 396             options: [{ max: 2, skipComments: true, skipBlankLines: false }],
 397             errors: [
 398                 { messageId: "exceed", data: { name: "Static method 'foo'", lineCount: 5, maxLines: 2 } }
 399             ]
 400         },
 401
 402         // Test getters are recognised as properties
 403         {
 404             code: `var obj = {
 405     get
 406     foo
 407     () {
 408         return 1
 409     }
 410 }`,
 411             options: [{ max: 2, skipComments: true, skipBlankLines: false }],
 412             errors: [
 413                 { messageId: "exceed", data: { name: "Getter 'foo'", lineCount: 5, maxLines: 2 } }
 414             ]
 415         },
 416
 417         // Test setters are recognised as properties
 418         {
 419             code: `var obj = {
 420     set
 421     foo
 422     ( val ) {
 423         this._foo = val;
 424     }
 425 }`,
 426             options: [{ max: 2, skipComments: true, skipBlankLines: false }],
 427             errors: [
 428                 { messageId: "exceed", data: { name: "Setter 'foo'", lineCount: 5, maxLines: 2 } }
 429             ]
 430         },
 431
 432         // Test computed property names
 433         {
 434             code: `class A {
 435     static
 436     [
 437         foo +
 438             bar
 439     ]
 440     (a) {
 441         return a
 442     }
 443 }`,
 444             options: [{ max: 2, skipComments: true, skipBlankLines: false }],
 445             errors: [
 446                 { messageId: "exceed", data: { name: "Static method", lineCount: 8, maxLines: 2 } }
 447             ]
 448         },
 449
 450         // Test the IIFEs option includes IIFEs
 451         {
 452             code: `(function(){
 453     let x = 0;
 454     let y = 0;
 455     let z = x + y;
 456     let foo = {};
 457     return bar;
 458 }());`,
 459             options: [{ max: 2, skipComments: true, skipBlankLines: false, IIFEs: true }],
 460             errors: [
 461                 { messageId: "exceed", data: { name: "Function", lineCount: 7, maxLines: 2 } }
 462             ]
 463         },
 464
 465         // Test the IIFEs option includes arrow IIFEs
 466         {
 467             code: `(() => {
 468     let x = 0;
 469     let y = 0;
 470     let z = x + y;
 471     let foo = {};
 472     return bar;
 473 })();`,
 474             options: [{ max: 2, skipComments: true, skipBlankLines: false, IIFEs: true }],
 475             errors: [
 476                 { messageId: "exceed", data: { name: "Arrow function", lineCount: 7, maxLines: 2 } }
 477             ]
 478         }
 479     ]
 480 });