| /** | |
|  * @fileoverview Rule to flag use of an empty block statement | |
|  * @author Nicholas C. Zakas | |
|  */ | |
| "use strict"; | |
| 
 | |
| //------------------------------------------------------------------------------ | |
| // Requirements | |
| //------------------------------------------------------------------------------ | |
|  | |
| const astUtils = require("./utils/ast-utils"); | |
| 
 | |
| //------------------------------------------------------------------------------ | |
| // Rule Definition | |
| //------------------------------------------------------------------------------ | |
|  | |
| /** @type {import('../shared/types').Rule} */ | |
| module.exports = { | |
|     meta: { | |
|         hasSuggestions: true, | |
|         type: "suggestion", | |
| 
 | |
|         docs: { | |
|             description: "Disallow empty block statements", | |
|             recommended: true, | |
|             url: "https://eslint.org/docs/latest/rules/no-empty" | |
|         }, | |
| 
 | |
|         schema: [ | |
|             { | |
|                 type: "object", | |
|                 properties: { | |
|                     allowEmptyCatch: { | |
|                         type: "boolean", | |
|                         default: false | |
|                     } | |
|                 }, | |
|                 additionalProperties: false | |
|             } | |
|         ], | |
| 
 | |
|         messages: { | |
|             unexpected: "Empty {{type}} statement.", | |
|             suggestComment: "Add comment inside empty {{type}} statement." | |
|         } | |
|     }, | |
| 
 | |
|     create(context) { | |
|         const options = context.options[0] || {}, | |
|             allowEmptyCatch = options.allowEmptyCatch || false; | |
| 
 | |
|         const sourceCode = context.sourceCode; | |
| 
 | |
|         return { | |
|             BlockStatement(node) { | |
| 
 | |
|                 // if the body is not empty, we can just return immediately | |
|                 if (node.body.length !== 0) { | |
|                     return; | |
|                 } | |
| 
 | |
|                 // a function is generally allowed to be empty | |
|                 if (astUtils.isFunction(node.parent)) { | |
|                     return; | |
|                 } | |
| 
 | |
|                 if (allowEmptyCatch && node.parent.type === "CatchClause") { | |
|                     return; | |
|                 } | |
| 
 | |
|                 // any other block is only allowed to be empty, if it contains a comment | |
|                 if (sourceCode.getCommentsInside(node).length > 0) { | |
|                     return; | |
|                 } | |
| 
 | |
|                 context.report({ | |
|                     node, | |
|                     messageId: "unexpected", | |
|                     data: { type: "block" }, | |
|                     suggest: [ | |
|                         { | |
|                             messageId: "suggestComment", | |
|                             data: { type: "block" }, | |
|                             fix(fixer) { | |
|                                 const range = [node.range[0] + 1, node.range[1] - 1]; | |
| 
 | |
|                                 return fixer.replaceTextRange(range, " /* empty */ "); | |
|                             } | |
|                         } | |
|                     ] | |
|                 }); | |
|             }, | |
| 
 | |
|             SwitchStatement(node) { | |
| 
 | |
|                 if (typeof node.cases === "undefined" || node.cases.length === 0) { | |
|                     context.report({ node, messageId: "unexpected", data: { type: "switch" } }); | |
|                 } | |
|             } | |
|         }; | |
| 
 | |
|     } | |
| };
 |