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