Permalink
Cannot retrieve contributors at this time
| /** | |
| * @fileoverview Rule to disallow if as the only statmenet in an else block | |
| * @author Brandon Mills | |
| */ | |
| "use strict"; | |
| //------------------------------------------------------------------------------ | |
| // Rule Definition | |
| //------------------------------------------------------------------------------ | |
| module.exports = { | |
| meta: { | |
| type: "suggestion", | |
| docs: { | |
| description: "disallow `if` statements as the only statement in `else` blocks", | |
| category: "Stylistic Issues", | |
| recommended: false, | |
| url: "https://eslint.org/docs/rules/no-lonely-if" | |
| }, | |
| schema: [], | |
| fixable: "code" | |
| }, | |
| create(context) { | |
| const sourceCode = context.getSourceCode(); | |
| return { | |
| IfStatement(node) { | |
| const ancestors = context.getAncestors(), | |
| parent = ancestors.pop(), | |
| grandparent = ancestors.pop(); | |
| if (parent && parent.type === "BlockStatement" && | |
| parent.body.length === 1 && grandparent && | |
| grandparent.type === "IfStatement" && | |
| parent === grandparent.alternate) { | |
| context.report({ | |
| node, | |
| message: "Unexpected if as the only statement in an else block.", | |
| fix(fixer) { | |
| const openingElseCurly = sourceCode.getFirstToken(parent); | |
| const closingElseCurly = sourceCode.getLastToken(parent); | |
| const elseKeyword = sourceCode.getTokenBefore(openingElseCurly); | |
| const tokenAfterElseBlock = sourceCode.getTokenAfter(closingElseCurly); | |
| const lastIfToken = sourceCode.getLastToken(node.consequent); | |
| const sourceText = sourceCode.getText(); | |
| if (sourceText.slice(openingElseCurly.range[1], | |
| node.range[0]).trim() || sourceText.slice(node.range[1], closingElseCurly.range[0]).trim()) { | |
| // Don't fix if there are any non-whitespace characters interfering (e.g. comments) | |
| return null; | |
| } | |
| if ( | |
| node.consequent.type !== "BlockStatement" && lastIfToken.value !== ";" && tokenAfterElseBlock && | |
| ( | |
| node.consequent.loc.end.line === tokenAfterElseBlock.loc.start.line || | |
| /^[([/+`-]/u.test(tokenAfterElseBlock.value) || | |
| lastIfToken.value === "++" || | |
| lastIfToken.value === "--" | |
| ) | |
| ) { | |
| /* | |
| * If the `if` statement has no block, and is not followed by a semicolon, make sure that fixing | |
| * the issue would not change semantics due to ASI. If this would happen, don't do a fix. | |
| */ | |
| return null; | |
| } | |
| return fixer.replaceTextRange( | |
| [openingElseCurly.range[0], closingElseCurly.range[1]], | |
| (elseKeyword.range[1] === openingElseCurly.range[0] ? " " : "") + sourceCode.getText(node) | |
| ); | |
| } | |
| }); | |
| } | |
| } | |
| }; | |
| } | |
| }; |