| /** | |
|  * @fileoverview Require or disallow Unicode BOM | |
|  * @author Andrew Johnston <https://github.com/ehjay> | |
|  */ | |
| "use strict"; | |
| 
 | |
| //------------------------------------------------------------------------------ | |
| // Rule Definition | |
| //------------------------------------------------------------------------------ | |
|  | |
| /** @type {import('../shared/types').Rule} */ | |
| module.exports = { | |
|     meta: { | |
|         type: "layout", | |
| 
 | |
|         docs: { | |
|             description: "Require or disallow Unicode byte order mark (BOM)", | |
|             recommended: false, | |
|             url: "https://eslint.org/docs/latest/rules/unicode-bom" | |
|         }, | |
| 
 | |
|         fixable: "whitespace", | |
| 
 | |
|         schema: [ | |
|             { | |
|                 enum: ["always", "never"] | |
|             } | |
|         ], | |
|         messages: { | |
|             expected: "Expected Unicode BOM (Byte Order Mark).", | |
|             unexpected: "Unexpected Unicode BOM (Byte Order Mark)." | |
|         } | |
|     }, | |
| 
 | |
|     create(context) { | |
| 
 | |
|         //-------------------------------------------------------------------------- | |
|         // Public | |
|         //-------------------------------------------------------------------------- | |
|  | |
|         return { | |
| 
 | |
|             Program: function checkUnicodeBOM(node) { | |
| 
 | |
|                 const sourceCode = context.sourceCode, | |
|                     location = { column: 0, line: 1 }, | |
|                     requireBOM = context.options[0] || "never"; | |
| 
 | |
|                 if (!sourceCode.hasBOM && (requireBOM === "always")) { | |
|                     context.report({ | |
|                         node, | |
|                         loc: location, | |
|                         messageId: "expected", | |
|                         fix(fixer) { | |
|                             return fixer.insertTextBeforeRange([0, 1], "\uFEFF"); | |
|                         } | |
|                     }); | |
|                 } else if (sourceCode.hasBOM && (requireBOM === "never")) { | |
|                     context.report({ | |
|                         node, | |
|                         loc: location, | |
|                         messageId: "unexpected", | |
|                         fix(fixer) { | |
|                             return fixer.removeRange([-1, 0]); | |
|                         } | |
|                     }); | |
|                 } | |
|             } | |
| 
 | |
|         }; | |
| 
 | |
|     } | |
| };
 |