diff options
Diffstat (limited to 'tools/node_modules/eslint/lib/rules/no-extra-parens.js')
| -rw-r--r-- | tools/node_modules/eslint/lib/rules/no-extra-parens.js | 258 |
1 files changed, 241 insertions, 17 deletions
diff --git a/tools/node_modules/eslint/lib/rules/no-extra-parens.js b/tools/node_modules/eslint/lib/rules/no-extra-parens.js index 98fc49654c..6c3198b5f0 100644 --- a/tools/node_modules/eslint/lib/rules/no-extra-parens.js +++ b/tools/node_modules/eslint/lib/rules/no-extra-parens.js @@ -81,6 +81,8 @@ module.exports = { const PRECEDENCE_OF_ASSIGNMENT_EXPR = precedence({ type: "AssignmentExpression" }); const PRECEDENCE_OF_UPDATE_EXPR = precedence({ type: "UpdateExpression" }); + let reportsBuffer; + /** * Determines if this rule should be enforced for a node given the current configuration. * @param {ASTNode} node - The node to be checked. @@ -316,19 +318,33 @@ module.exports = { } } - context.report({ - node, - loc: leftParenToken.loc.start, - messageId: "unexpected", - fix(fixer) { - const parenthesizedSource = sourceCode.text.slice(leftParenToken.range[1], rightParenToken.range[0]); + /** + * Finishes reporting + * @returns {void} + * @private + */ + function finishReport() { + context.report({ + node, + loc: leftParenToken.loc.start, + messageId: "unexpected", + fix(fixer) { + const parenthesizedSource = sourceCode.text.slice(leftParenToken.range[1], rightParenToken.range[0]); + + return fixer.replaceTextRange([ + leftParenToken.range[0], + rightParenToken.range[1] + ], (requiresLeadingSpace(node) ? " " : "") + parenthesizedSource + (requiresTrailingSpace(node) ? " " : "")); + } + }); + } - return fixer.replaceTextRange([ - leftParenToken.range[0], - rightParenToken.range[1] - ], (requiresLeadingSpace(node) ? " " : "") + parenthesizedSource + (requiresTrailingSpace(node) ? " " : "")); - } - }); + if (reportsBuffer) { + reportsBuffer.reports.push({ node, finishReport }); + return; + } + + finishReport(); } /** @@ -498,6 +514,126 @@ module.exports = { } } + /** + * Finds the path from the given node to the specified ancestor. + * @param {ASTNode} node First node in the path. + * @param {ASTNode} ancestor Last node in the path. + * @returns {ASTNode[]} Path, including both nodes. + * @throws {Error} If the given node does not have the specified ancestor. + */ + function pathToAncestor(node, ancestor) { + const path = [node]; + let currentNode = node; + + while (currentNode !== ancestor) { + + currentNode = currentNode.parent; + + /* istanbul ignore if */ + if (currentNode === null) { + throw new Error("Nodes are not in the ancestor-descendant relationship."); + } + + path.push(currentNode); + } + + return path; + } + + /** + * Finds the path from the given node to the specified descendant. + * @param {ASTNode} node First node in the path. + * @param {ASTNode} descendant Last node in the path. + * @returns {ASTNode[]} Path, including both nodes. + * @throws {Error} If the given node does not have the specified descendant. + */ + function pathToDescendant(node, descendant) { + return pathToAncestor(descendant, node).reverse(); + } + + /** + * Checks whether the syntax of the given ancestor of an 'in' expression inside a for-loop initializer + * is preventing the 'in' keyword from being interpreted as a part of an ill-formed for-in loop. + * + * @param {ASTNode} node Ancestor of an 'in' expression. + * @param {ASTNode} child Child of the node, ancestor of the same 'in' expression or the 'in' expression itself. + * @returns {boolean} True if the keyword 'in' would be interpreted as the 'in' operator, without any parenthesis. + */ + function isSafelyEnclosingInExpression(node, child) { + switch (node.type) { + case "ArrayExpression": + case "ArrayPattern": + case "BlockStatement": + case "ObjectExpression": + case "ObjectPattern": + case "TemplateLiteral": + return true; + case "ArrowFunctionExpression": + case "FunctionExpression": + return node.params.includes(child); + case "CallExpression": + case "NewExpression": + return node.arguments.includes(child); + case "MemberExpression": + return node.computed && node.property === child; + case "ConditionalExpression": + return node.consequent === child; + default: + return false; + } + } + + /** + * Starts a new reports buffering. Warnings will be stored in a buffer instead of being reported immediately. + * An additional logic that requires multiple nodes (e.g. a whole subtree) may dismiss some of the stored warnings. + * + * @returns {void} + */ + function startNewReportsBuffering() { + reportsBuffer = { + upper: reportsBuffer, + inExpressionNodes: [], + reports: [] + }; + } + + /** + * Ends the current reports buffering. + * @returns {void} + */ + function endCurrentReportsBuffering() { + const { upper, inExpressionNodes, reports } = reportsBuffer; + + if (upper) { + upper.inExpressionNodes.push(...inExpressionNodes); + upper.reports.push(...reports); + } else { + + // flush remaining reports + reports.forEach(({ finishReport }) => finishReport()); + } + + reportsBuffer = upper; + } + + /** + * Checks whether the given node is in the current reports buffer. + * @param {ASTNode} node Node to check. + * @returns {boolean} True if the node is in the current buffer, false otherwise. + */ + function isInCurrentReportsBuffer(node) { + return reportsBuffer.reports.some(r => r.node === node); + } + + /** + * Removes the given node from the current reports buffer. + * @param {ASTNode} node Node to remove. + * @returns {void} + */ + function removeFromCurrentReportsBuffer(node) { + reportsBuffer.reports = reportsBuffer.reports.filter(r => r.node !== node); + } + return { ArrayExpression(node) { node.elements @@ -540,7 +676,14 @@ module.exports = { } }, - BinaryExpression: checkBinaryLogical, + BinaryExpression(node) { + if (reportsBuffer && node.operator === "in") { + reportsBuffer.inExpressionNodes.push(node); + } + + checkBinaryLogical(node); + }, + CallExpression: checkCallNew, ConditionalExpression(node) { @@ -602,10 +745,6 @@ module.exports = { }, ForStatement(node) { - if (node.init && hasExcessParens(node.init)) { - report(node.init); - } - if (node.test && hasExcessParens(node.test) && !isCondAssignException(node)) { report(node.test); } @@ -613,6 +752,81 @@ module.exports = { if (node.update && hasExcessParens(node.update)) { report(node.update); } + + if (node.init) { + startNewReportsBuffering(); + + if (hasExcessParens(node.init)) { + report(node.init); + } + } + }, + + "ForStatement > *.init:exit"(node) { + + /* + * Removing parentheses around `in` expressions might change semantics and cause errors. + * + * For example, this valid for loop: + * for (let a = (b in c); ;); + * after removing parentheses would be treated as an invalid for-in loop: + * for (let a = b in c; ;); + */ + + if (reportsBuffer.reports.length) { + reportsBuffer.inExpressionNodes.forEach(inExpressionNode => { + const path = pathToDescendant(node, inExpressionNode); + let nodeToExclude; + + for (let i = 0; i < path.length; i++) { + const pathNode = path[i]; + + if (i < path.length - 1) { + const nextPathNode = path[i + 1]; + + if (isSafelyEnclosingInExpression(pathNode, nextPathNode)) { + + // The 'in' expression in safely enclosed by the syntax of its ancestor nodes (e.g. by '{}' or '[]'). + return; + } + } + + if (isParenthesised(pathNode)) { + if (isInCurrentReportsBuffer(pathNode)) { + + // This node was supposed to be reported, but parentheses might be necessary. + + if (isParenthesisedTwice(pathNode)) { + + /* + * This node is parenthesised twice, it certainly has at least one pair of `extra` parentheses. + * If the --fix option is on, the current fixing iteration will remove only one pair of parentheses. + * The remaining pair is safely enclosing the 'in' expression. + */ + return; + } + + // Exclude the outermost node only. + if (!nodeToExclude) { + nodeToExclude = pathNode; + } + + // Don't break the loop here, there might be some safe nodes or parentheses that will stay inside. + + } else { + + // This node will stay parenthesised, the 'in' expression in safely enclosed by '()'. + return; + } + } + } + + // Exclude the node from the list (i.e. treat parentheses as necessary) + removeFromCurrentReportsBuffer(nodeToExclude); + }); + } + + endCurrentReportsBuffering(); }, IfStatement(node) { @@ -664,6 +878,16 @@ module.exports = { }).forEach(property => report(property.value)); }, + Property(node) { + if (node.computed) { + const { key } = node; + + if (key && hasExcessParens(key) && precedence(key) >= PRECEDENCE_OF_ASSIGNMENT_EXPR) { + report(key); + } + } + }, + ReturnStatement(node) { const returnToken = sourceCode.getFirstToken(node); |