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1235 lines
47 KiB
1235 lines
47 KiB
/** |
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* @fileoverview Disallow parenthesising higher precedence subexpressions. |
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* @author Michael Ficarra |
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*/ |
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"use strict"; |
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|
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//------------------------------------------------------------------------------ |
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// Rule Definition |
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//------------------------------------------------------------------------------ |
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|
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const { isParenthesized: isParenthesizedRaw } = require("eslint-utils"); |
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const astUtils = require("./utils/ast-utils.js"); |
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|
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/** @type {import('../shared/types').Rule} */ |
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module.exports = { |
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meta: { |
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type: "layout", |
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|
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docs: { |
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description: "Disallow unnecessary parentheses", |
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recommended: false, |
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url: "https://eslint.org/docs/rules/no-extra-parens" |
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}, |
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fixable: "code", |
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schema: { |
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anyOf: [ |
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{ |
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type: "array", |
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items: [ |
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{ |
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enum: ["functions"] |
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} |
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], |
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minItems: 0, |
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maxItems: 1 |
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}, |
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{ |
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type: "array", |
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items: [ |
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{ |
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enum: ["all"] |
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}, |
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{ |
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type: "object", |
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properties: { |
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conditionalAssign: { type: "boolean" }, |
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nestedBinaryExpressions: { type: "boolean" }, |
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returnAssign: { type: "boolean" }, |
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ignoreJSX: { enum: ["none", "all", "single-line", "multi-line"] }, |
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enforceForArrowConditionals: { type: "boolean" }, |
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enforceForSequenceExpressions: { type: "boolean" }, |
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enforceForNewInMemberExpressions: { type: "boolean" }, |
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enforceForFunctionPrototypeMethods: { type: "boolean" } |
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}, |
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additionalProperties: false |
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} |
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], |
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minItems: 0, |
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maxItems: 2 |
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} |
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] |
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}, |
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|
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messages: { |
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unexpected: "Unnecessary parentheses around expression." |
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} |
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}, |
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|
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create(context) { |
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const sourceCode = context.getSourceCode(); |
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|
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const tokensToIgnore = new WeakSet(); |
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const precedence = astUtils.getPrecedence; |
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const ALL_NODES = context.options[0] !== "functions"; |
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const EXCEPT_COND_ASSIGN = ALL_NODES && context.options[1] && context.options[1].conditionalAssign === false; |
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const NESTED_BINARY = ALL_NODES && context.options[1] && context.options[1].nestedBinaryExpressions === false; |
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const EXCEPT_RETURN_ASSIGN = ALL_NODES && context.options[1] && context.options[1].returnAssign === false; |
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const IGNORE_JSX = ALL_NODES && context.options[1] && context.options[1].ignoreJSX; |
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const IGNORE_ARROW_CONDITIONALS = ALL_NODES && context.options[1] && |
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context.options[1].enforceForArrowConditionals === false; |
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const IGNORE_SEQUENCE_EXPRESSIONS = ALL_NODES && context.options[1] && |
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context.options[1].enforceForSequenceExpressions === false; |
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const IGNORE_NEW_IN_MEMBER_EXPR = ALL_NODES && context.options[1] && |
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context.options[1].enforceForNewInMemberExpressions === false; |
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const IGNORE_FUNCTION_PROTOTYPE_METHODS = ALL_NODES && context.options[1] && |
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context.options[1].enforceForFunctionPrototypeMethods === false; |
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|
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const PRECEDENCE_OF_ASSIGNMENT_EXPR = precedence({ type: "AssignmentExpression" }); |
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const PRECEDENCE_OF_UPDATE_EXPR = precedence({ type: "UpdateExpression" }); |
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|
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let reportsBuffer; |
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|
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/** |
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* Determines whether the given node is a `call` or `apply` method call, invoked directly on a `FunctionExpression` node. |
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* Example: function(){}.call() |
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* @param {ASTNode} node The node to be checked. |
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* @returns {boolean} True if the node is an immediate `call` or `apply` method call. |
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* @private |
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*/ |
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function isImmediateFunctionPrototypeMethodCall(node) { |
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const callNode = astUtils.skipChainExpression(node); |
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|
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if (callNode.type !== "CallExpression") { |
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return false; |
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} |
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const callee = astUtils.skipChainExpression(callNode.callee); |
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|
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return ( |
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callee.type === "MemberExpression" && |
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callee.object.type === "FunctionExpression" && |
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["call", "apply"].includes(astUtils.getStaticPropertyName(callee)) |
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); |
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} |
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|
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/** |
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* Determines if this rule should be enforced for a node given the current configuration. |
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* @param {ASTNode} node The node to be checked. |
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* @returns {boolean} True if the rule should be enforced for this node. |
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* @private |
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*/ |
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function ruleApplies(node) { |
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if (node.type === "JSXElement" || node.type === "JSXFragment") { |
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const isSingleLine = node.loc.start.line === node.loc.end.line; |
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switch (IGNORE_JSX) { |
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|
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// Exclude this JSX element from linting |
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case "all": |
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return false; |
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|
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// Exclude this JSX element if it is multi-line element |
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case "multi-line": |
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return isSingleLine; |
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|
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// Exclude this JSX element if it is single-line element |
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case "single-line": |
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return !isSingleLine; |
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|
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// Nothing special to be done for JSX elements |
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case "none": |
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break; |
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|
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// no default |
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} |
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} |
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|
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if (node.type === "SequenceExpression" && IGNORE_SEQUENCE_EXPRESSIONS) { |
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return false; |
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} |
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|
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if (isImmediateFunctionPrototypeMethodCall(node) && IGNORE_FUNCTION_PROTOTYPE_METHODS) { |
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return false; |
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} |
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|
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return ALL_NODES || node.type === "FunctionExpression" || node.type === "ArrowFunctionExpression"; |
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} |
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|
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/** |
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* Determines if a node is surrounded by parentheses. |
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* @param {ASTNode} node The node to be checked. |
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* @returns {boolean} True if the node is parenthesised. |
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* @private |
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*/ |
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function isParenthesised(node) { |
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return isParenthesizedRaw(1, node, sourceCode); |
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} |
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|
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/** |
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* Determines if a node is surrounded by parentheses twice. |
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* @param {ASTNode} node The node to be checked. |
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* @returns {boolean} True if the node is doubly parenthesised. |
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* @private |
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*/ |
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function isParenthesisedTwice(node) { |
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return isParenthesizedRaw(2, node, sourceCode); |
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} |
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|
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/** |
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* Determines if a node is surrounded by (potentially) invalid parentheses. |
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* @param {ASTNode} node The node to be checked. |
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* @returns {boolean} True if the node is incorrectly parenthesised. |
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* @private |
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*/ |
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function hasExcessParens(node) { |
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return ruleApplies(node) && isParenthesised(node); |
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} |
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|
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/** |
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* Determines if a node that is expected to be parenthesised is surrounded by |
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* (potentially) invalid extra parentheses. |
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* @param {ASTNode} node The node to be checked. |
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* @returns {boolean} True if the node is has an unexpected extra pair of parentheses. |
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* @private |
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*/ |
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function hasDoubleExcessParens(node) { |
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return ruleApplies(node) && isParenthesisedTwice(node); |
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} |
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/** |
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* Determines if a node that is expected to be parenthesised is surrounded by |
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* (potentially) invalid extra parentheses with considering precedence level of the node. |
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* If the preference level of the node is not higher or equal to precedence lower limit, it also checks |
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* whether the node is surrounded by parentheses twice or not. |
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* @param {ASTNode} node The node to be checked. |
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* @param {number} precedenceLowerLimit The lower limit of precedence. |
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* @returns {boolean} True if the node is has an unexpected extra pair of parentheses. |
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* @private |
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*/ |
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function hasExcessParensWithPrecedence(node, precedenceLowerLimit) { |
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if (ruleApplies(node) && isParenthesised(node)) { |
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if ( |
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precedence(node) >= precedenceLowerLimit || |
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isParenthesisedTwice(node) |
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) { |
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return true; |
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} |
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} |
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return false; |
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} |
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|
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/** |
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* Determines if a node test expression is allowed to have a parenthesised assignment |
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* @param {ASTNode} node The node to be checked. |
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* @returns {boolean} True if the assignment can be parenthesised. |
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* @private |
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*/ |
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function isCondAssignException(node) { |
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return EXCEPT_COND_ASSIGN && node.test.type === "AssignmentExpression"; |
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} |
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|
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/** |
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* Determines if a node is in a return statement |
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* @param {ASTNode} node The node to be checked. |
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* @returns {boolean} True if the node is in a return statement. |
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* @private |
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*/ |
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function isInReturnStatement(node) { |
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for (let currentNode = node; currentNode; currentNode = currentNode.parent) { |
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if ( |
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currentNode.type === "ReturnStatement" || |
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(currentNode.type === "ArrowFunctionExpression" && currentNode.body.type !== "BlockStatement") |
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) { |
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return true; |
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} |
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} |
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return false; |
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} |
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|
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/** |
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* Determines if a constructor function is newed-up with parens |
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* @param {ASTNode} newExpression The NewExpression node to be checked. |
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* @returns {boolean} True if the constructor is called with parens. |
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* @private |
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*/ |
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function isNewExpressionWithParens(newExpression) { |
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const lastToken = sourceCode.getLastToken(newExpression); |
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const penultimateToken = sourceCode.getTokenBefore(lastToken); |
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|
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return newExpression.arguments.length > 0 || |
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( |
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|
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// The expression should end with its own parens, e.g., new new foo() is not a new expression with parens |
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astUtils.isOpeningParenToken(penultimateToken) && |
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astUtils.isClosingParenToken(lastToken) && |
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newExpression.callee.range[1] < newExpression.range[1] |
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); |
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} |
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|
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/** |
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* Determines if a node is or contains an assignment expression |
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* @param {ASTNode} node The node to be checked. |
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* @returns {boolean} True if the node is or contains an assignment expression. |
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* @private |
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*/ |
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function containsAssignment(node) { |
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if (node.type === "AssignmentExpression") { |
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return true; |
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} |
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if (node.type === "ConditionalExpression" && |
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(node.consequent.type === "AssignmentExpression" || node.alternate.type === "AssignmentExpression")) { |
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return true; |
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} |
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if ((node.left && node.left.type === "AssignmentExpression") || |
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(node.right && node.right.type === "AssignmentExpression")) { |
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return true; |
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} |
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|
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return false; |
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} |
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|
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/** |
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* Determines if a node is contained by or is itself a return statement and is allowed to have a parenthesised assignment |
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* @param {ASTNode} node The node to be checked. |
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* @returns {boolean} True if the assignment can be parenthesised. |
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* @private |
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*/ |
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function isReturnAssignException(node) { |
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if (!EXCEPT_RETURN_ASSIGN || !isInReturnStatement(node)) { |
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return false; |
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} |
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|
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if (node.type === "ReturnStatement") { |
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return node.argument && containsAssignment(node.argument); |
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} |
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if (node.type === "ArrowFunctionExpression" && node.body.type !== "BlockStatement") { |
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return containsAssignment(node.body); |
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} |
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return containsAssignment(node); |
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|
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} |
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/** |
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* Determines if a node following a [no LineTerminator here] restriction is |
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* surrounded by (potentially) invalid extra parentheses. |
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* @param {Token} token The token preceding the [no LineTerminator here] restriction. |
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* @param {ASTNode} node The node to be checked. |
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* @returns {boolean} True if the node is incorrectly parenthesised. |
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* @private |
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*/ |
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function hasExcessParensNoLineTerminator(token, node) { |
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if (token.loc.end.line === node.loc.start.line) { |
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return hasExcessParens(node); |
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} |
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|
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return hasDoubleExcessParens(node); |
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} |
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|
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/** |
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* Determines whether a node should be preceded by an additional space when removing parens |
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* @param {ASTNode} node node to evaluate; must be surrounded by parentheses |
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* @returns {boolean} `true` if a space should be inserted before the node |
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* @private |
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*/ |
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function requiresLeadingSpace(node) { |
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const leftParenToken = sourceCode.getTokenBefore(node); |
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const tokenBeforeLeftParen = sourceCode.getTokenBefore(leftParenToken, { includeComments: true }); |
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const tokenAfterLeftParen = sourceCode.getTokenAfter(leftParenToken, { includeComments: true }); |
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|
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return tokenBeforeLeftParen && |
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tokenBeforeLeftParen.range[1] === leftParenToken.range[0] && |
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leftParenToken.range[1] === tokenAfterLeftParen.range[0] && |
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!astUtils.canTokensBeAdjacent(tokenBeforeLeftParen, tokenAfterLeftParen); |
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} |
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|
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/** |
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* Determines whether a node should be followed by an additional space when removing parens |
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* @param {ASTNode} node node to evaluate; must be surrounded by parentheses |
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* @returns {boolean} `true` if a space should be inserted after the node |
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* @private |
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*/ |
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function requiresTrailingSpace(node) { |
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const nextTwoTokens = sourceCode.getTokensAfter(node, { count: 2 }); |
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const rightParenToken = nextTwoTokens[0]; |
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const tokenAfterRightParen = nextTwoTokens[1]; |
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const tokenBeforeRightParen = sourceCode.getLastToken(node); |
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|
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return rightParenToken && tokenAfterRightParen && |
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!sourceCode.isSpaceBetweenTokens(rightParenToken, tokenAfterRightParen) && |
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!astUtils.canTokensBeAdjacent(tokenBeforeRightParen, tokenAfterRightParen); |
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} |
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|
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/** |
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* Determines if a given expression node is an IIFE |
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* @param {ASTNode} node The node to check |
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* @returns {boolean} `true` if the given node is an IIFE |
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*/ |
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function isIIFE(node) { |
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const maybeCallNode = astUtils.skipChainExpression(node); |
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|
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return maybeCallNode.type === "CallExpression" && maybeCallNode.callee.type === "FunctionExpression"; |
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} |
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|
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/** |
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* Determines if the given node can be the assignment target in destructuring or the LHS of an assignment. |
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* This is to avoid an autofix that could change behavior because parsers mistakenly allow invalid syntax, |
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* such as `(a = b) = c` and `[(a = b) = c] = []`. Ideally, this function shouldn't be necessary. |
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* @param {ASTNode} [node] The node to check |
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* @returns {boolean} `true` if the given node can be a valid assignment target |
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*/ |
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function canBeAssignmentTarget(node) { |
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return node && (node.type === "Identifier" || node.type === "MemberExpression"); |
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} |
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|
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/** |
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* Report the node |
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* @param {ASTNode} node node to evaluate |
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* @returns {void} |
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* @private |
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*/ |
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function report(node) { |
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const leftParenToken = sourceCode.getTokenBefore(node); |
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const rightParenToken = sourceCode.getTokenAfter(node); |
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|
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if (!isParenthesisedTwice(node)) { |
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if (tokensToIgnore.has(sourceCode.getFirstToken(node))) { |
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return; |
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} |
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|
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if (isIIFE(node) && !isParenthesised(node.callee)) { |
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return; |
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} |
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} |
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|
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/** |
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* Finishes reporting |
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* @returns {void} |
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* @private |
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*/ |
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function finishReport() { |
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context.report({ |
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node, |
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loc: leftParenToken.loc, |
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messageId: "unexpected", |
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fix(fixer) { |
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const parenthesizedSource = sourceCode.text.slice(leftParenToken.range[1], rightParenToken.range[0]); |
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|
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return fixer.replaceTextRange([ |
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leftParenToken.range[0], |
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rightParenToken.range[1] |
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], (requiresLeadingSpace(node) ? " " : "") + parenthesizedSource + (requiresTrailingSpace(node) ? " " : "")); |
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} |
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}); |
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} |
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|
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if (reportsBuffer) { |
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reportsBuffer.reports.push({ node, finishReport }); |
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return; |
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} |
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|
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finishReport(); |
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} |
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|
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/** |
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* Evaluate a argument of the node. |
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* @param {ASTNode} node node to evaluate |
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* @returns {void} |
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* @private |
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*/ |
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function checkArgumentWithPrecedence(node) { |
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if (hasExcessParensWithPrecedence(node.argument, precedence(node))) { |
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report(node.argument); |
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} |
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} |
|
|
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/** |
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* Check if a member expression contains a call expression |
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* @param {ASTNode} node MemberExpression node to evaluate |
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* @returns {boolean} true if found, false if not |
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*/ |
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function doesMemberExpressionContainCallExpression(node) { |
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let currentNode = node.object; |
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let currentNodeType = node.object.type; |
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|
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while (currentNodeType === "MemberExpression") { |
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currentNode = currentNode.object; |
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currentNodeType = currentNode.type; |
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} |
|
|
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return currentNodeType === "CallExpression"; |
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} |
|
|
|
/** |
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* Evaluate a new call |
|
* @param {ASTNode} node node to evaluate |
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* @returns {void} |
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* @private |
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*/ |
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function checkCallNew(node) { |
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const callee = node.callee; |
|
|
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if (hasExcessParensWithPrecedence(callee, precedence(node))) { |
|
if ( |
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hasDoubleExcessParens(callee) || |
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!( |
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isIIFE(node) || |
|
|
|
// (new A)(); new (new A)(); |
|
( |
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callee.type === "NewExpression" && |
|
!isNewExpressionWithParens(callee) && |
|
!( |
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node.type === "NewExpression" && |
|
!isNewExpressionWithParens(node) |
|
) |
|
) || |
|
|
|
// new (a().b)(); new (a.b().c); |
|
( |
|
node.type === "NewExpression" && |
|
callee.type === "MemberExpression" && |
|
doesMemberExpressionContainCallExpression(callee) |
|
) || |
|
|
|
// (a?.b)(); (a?.())(); |
|
( |
|
!node.optional && |
|
callee.type === "ChainExpression" |
|
) |
|
) |
|
) { |
|
report(node.callee); |
|
} |
|
} |
|
node.arguments |
|
.filter(arg => hasExcessParensWithPrecedence(arg, PRECEDENCE_OF_ASSIGNMENT_EXPR)) |
|
.forEach(report); |
|
} |
|
|
|
/** |
|
* Evaluate binary logicals |
|
* @param {ASTNode} node node to evaluate |
|
* @returns {void} |
|
* @private |
|
*/ |
|
function checkBinaryLogical(node) { |
|
const prec = precedence(node); |
|
const leftPrecedence = precedence(node.left); |
|
const rightPrecedence = precedence(node.right); |
|
const isExponentiation = node.operator === "**"; |
|
const shouldSkipLeft = NESTED_BINARY && (node.left.type === "BinaryExpression" || node.left.type === "LogicalExpression"); |
|
const shouldSkipRight = NESTED_BINARY && (node.right.type === "BinaryExpression" || node.right.type === "LogicalExpression"); |
|
|
|
if (!shouldSkipLeft && hasExcessParens(node.left)) { |
|
if ( |
|
!(["AwaitExpression", "UnaryExpression"].includes(node.left.type) && isExponentiation) && |
|
!astUtils.isMixedLogicalAndCoalesceExpressions(node.left, node) && |
|
(leftPrecedence > prec || (leftPrecedence === prec && !isExponentiation)) || |
|
isParenthesisedTwice(node.left) |
|
) { |
|
report(node.left); |
|
} |
|
} |
|
|
|
if (!shouldSkipRight && hasExcessParens(node.right)) { |
|
if ( |
|
!astUtils.isMixedLogicalAndCoalesceExpressions(node.right, node) && |
|
(rightPrecedence > prec || (rightPrecedence === prec && isExponentiation)) || |
|
isParenthesisedTwice(node.right) |
|
) { |
|
report(node.right); |
|
} |
|
} |
|
} |
|
|
|
/** |
|
* Check the parentheses around the super class of the given class definition. |
|
* @param {ASTNode} node The node of class declarations to check. |
|
* @returns {void} |
|
*/ |
|
function checkClass(node) { |
|
if (!node.superClass) { |
|
return; |
|
} |
|
|
|
/* |
|
* If `node.superClass` is a LeftHandSideExpression, parentheses are extra. |
|
* Otherwise, parentheses are needed. |
|
*/ |
|
const hasExtraParens = precedence(node.superClass) > PRECEDENCE_OF_UPDATE_EXPR |
|
? hasExcessParens(node.superClass) |
|
: hasDoubleExcessParens(node.superClass); |
|
|
|
if (hasExtraParens) { |
|
report(node.superClass); |
|
} |
|
} |
|
|
|
/** |
|
* Check the parentheses around the argument of the given spread operator. |
|
* @param {ASTNode} node The node of spread elements/properties to check. |
|
* @returns {void} |
|
*/ |
|
function checkSpreadOperator(node) { |
|
if (hasExcessParensWithPrecedence(node.argument, PRECEDENCE_OF_ASSIGNMENT_EXPR)) { |
|
report(node.argument); |
|
} |
|
} |
|
|
|
/** |
|
* Checks the parentheses for an ExpressionStatement or ExportDefaultDeclaration |
|
* @param {ASTNode} node The ExpressionStatement.expression or ExportDefaultDeclaration.declaration node |
|
* @returns {void} |
|
*/ |
|
function checkExpressionOrExportStatement(node) { |
|
const firstToken = isParenthesised(node) ? sourceCode.getTokenBefore(node) : sourceCode.getFirstToken(node); |
|
const secondToken = sourceCode.getTokenAfter(firstToken, astUtils.isNotOpeningParenToken); |
|
const thirdToken = secondToken ? sourceCode.getTokenAfter(secondToken) : null; |
|
const tokenAfterClosingParens = secondToken ? sourceCode.getTokenAfter(secondToken, astUtils.isNotClosingParenToken) : null; |
|
|
|
if ( |
|
astUtils.isOpeningParenToken(firstToken) && |
|
( |
|
astUtils.isOpeningBraceToken(secondToken) || |
|
secondToken.type === "Keyword" && ( |
|
secondToken.value === "function" || |
|
secondToken.value === "class" || |
|
secondToken.value === "let" && |
|
tokenAfterClosingParens && |
|
( |
|
astUtils.isOpeningBracketToken(tokenAfterClosingParens) || |
|
tokenAfterClosingParens.type === "Identifier" |
|
) |
|
) || |
|
secondToken && secondToken.type === "Identifier" && secondToken.value === "async" && thirdToken && thirdToken.type === "Keyword" && thirdToken.value === "function" |
|
) |
|
) { |
|
tokensToIgnore.add(secondToken); |
|
} |
|
|
|
const hasExtraParens = node.parent.type === "ExportDefaultDeclaration" |
|
? hasExcessParensWithPrecedence(node, PRECEDENCE_OF_ASSIGNMENT_EXPR) |
|
: hasExcessParens(node); |
|
|
|
if (hasExtraParens) { |
|
report(node); |
|
} |
|
} |
|
|
|
/** |
|
* 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); |
|
} |
|
|
|
/** |
|
* Checks whether a node is a MemberExpression at NewExpression's callee. |
|
* @param {ASTNode} node node to check. |
|
* @returns {boolean} True if the node is a MemberExpression at NewExpression's callee. false otherwise. |
|
*/ |
|
function isMemberExpInNewCallee(node) { |
|
if (node.type === "MemberExpression") { |
|
return node.parent.type === "NewExpression" && node.parent.callee === node |
|
? true |
|
: node.parent.object === node && isMemberExpInNewCallee(node.parent); |
|
} |
|
return false; |
|
} |
|
|
|
return { |
|
ArrayExpression(node) { |
|
node.elements |
|
.filter(e => e && hasExcessParensWithPrecedence(e, PRECEDENCE_OF_ASSIGNMENT_EXPR)) |
|
.forEach(report); |
|
}, |
|
|
|
ArrayPattern(node) { |
|
node.elements |
|
.filter(e => canBeAssignmentTarget(e) && hasExcessParens(e)) |
|
.forEach(report); |
|
}, |
|
|
|
ArrowFunctionExpression(node) { |
|
if (isReturnAssignException(node)) { |
|
return; |
|
} |
|
|
|
if (node.body.type === "ConditionalExpression" && |
|
IGNORE_ARROW_CONDITIONALS |
|
) { |
|
return; |
|
} |
|
|
|
if (node.body.type !== "BlockStatement") { |
|
const firstBodyToken = sourceCode.getFirstToken(node.body, astUtils.isNotOpeningParenToken); |
|
const tokenBeforeFirst = sourceCode.getTokenBefore(firstBodyToken); |
|
|
|
if (astUtils.isOpeningParenToken(tokenBeforeFirst) && astUtils.isOpeningBraceToken(firstBodyToken)) { |
|
tokensToIgnore.add(firstBodyToken); |
|
} |
|
if (hasExcessParensWithPrecedence(node.body, PRECEDENCE_OF_ASSIGNMENT_EXPR)) { |
|
report(node.body); |
|
} |
|
} |
|
}, |
|
|
|
AssignmentExpression(node) { |
|
if (canBeAssignmentTarget(node.left) && hasExcessParens(node.left)) { |
|
report(node.left); |
|
} |
|
|
|
if (!isReturnAssignException(node) && hasExcessParensWithPrecedence(node.right, precedence(node))) { |
|
report(node.right); |
|
} |
|
}, |
|
|
|
BinaryExpression(node) { |
|
if (reportsBuffer && node.operator === "in") { |
|
reportsBuffer.inExpressionNodes.push(node); |
|
} |
|
|
|
checkBinaryLogical(node); |
|
}, |
|
|
|
CallExpression: checkCallNew, |
|
|
|
ConditionalExpression(node) { |
|
if (isReturnAssignException(node)) { |
|
return; |
|
} |
|
if ( |
|
!isCondAssignException(node) && |
|
hasExcessParensWithPrecedence(node.test, precedence({ type: "LogicalExpression", operator: "||" })) |
|
) { |
|
report(node.test); |
|
} |
|
|
|
if (hasExcessParensWithPrecedence(node.consequent, PRECEDENCE_OF_ASSIGNMENT_EXPR)) { |
|
report(node.consequent); |
|
} |
|
|
|
if (hasExcessParensWithPrecedence(node.alternate, PRECEDENCE_OF_ASSIGNMENT_EXPR)) { |
|
report(node.alternate); |
|
} |
|
}, |
|
|
|
DoWhileStatement(node) { |
|
if (hasExcessParens(node.test) && !isCondAssignException(node)) { |
|
report(node.test); |
|
} |
|
}, |
|
|
|
ExportDefaultDeclaration: node => checkExpressionOrExportStatement(node.declaration), |
|
ExpressionStatement: node => checkExpressionOrExportStatement(node.expression), |
|
|
|
ForInStatement(node) { |
|
if (node.left.type !== "VariableDeclaration") { |
|
const firstLeftToken = sourceCode.getFirstToken(node.left, astUtils.isNotOpeningParenToken); |
|
|
|
if ( |
|
firstLeftToken.value === "let" && |
|
astUtils.isOpeningBracketToken( |
|
sourceCode.getTokenAfter(firstLeftToken, astUtils.isNotClosingParenToken) |
|
) |
|
) { |
|
|
|
// ForInStatement#left expression cannot start with `let[`. |
|
tokensToIgnore.add(firstLeftToken); |
|
} |
|
} |
|
|
|
if (hasExcessParens(node.left)) { |
|
report(node.left); |
|
} |
|
|
|
if (hasExcessParens(node.right)) { |
|
report(node.right); |
|
} |
|
}, |
|
|
|
ForOfStatement(node) { |
|
if (node.left.type !== "VariableDeclaration") { |
|
const firstLeftToken = sourceCode.getFirstToken(node.left, astUtils.isNotOpeningParenToken); |
|
|
|
if (firstLeftToken.value === "let") { |
|
|
|
// ForOfStatement#left expression cannot start with `let`. |
|
tokensToIgnore.add(firstLeftToken); |
|
} |
|
} |
|
|
|
if (hasExcessParens(node.left)) { |
|
report(node.left); |
|
} |
|
|
|
if (hasExcessParensWithPrecedence(node.right, PRECEDENCE_OF_ASSIGNMENT_EXPR)) { |
|
report(node.right); |
|
} |
|
}, |
|
|
|
ForStatement(node) { |
|
if (node.test && hasExcessParens(node.test) && !isCondAssignException(node)) { |
|
report(node.test); |
|
} |
|
|
|
if (node.update && hasExcessParens(node.update)) { |
|
report(node.update); |
|
} |
|
|
|
if (node.init) { |
|
|
|
if (node.init.type !== "VariableDeclaration") { |
|
const firstToken = sourceCode.getFirstToken(node.init, astUtils.isNotOpeningParenToken); |
|
|
|
if ( |
|
firstToken.value === "let" && |
|
astUtils.isOpeningBracketToken( |
|
sourceCode.getTokenAfter(firstToken, astUtils.isNotClosingParenToken) |
|
) |
|
) { |
|
|
|
// ForStatement#init expression cannot start with `let[`. |
|
tokensToIgnore.add(firstToken); |
|
} |
|
} |
|
|
|
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) { |
|
if (hasExcessParens(node.test) && !isCondAssignException(node)) { |
|
report(node.test); |
|
} |
|
}, |
|
|
|
ImportExpression(node) { |
|
const { source } = node; |
|
|
|
if (source.type === "SequenceExpression") { |
|
if (hasDoubleExcessParens(source)) { |
|
report(source); |
|
} |
|
} else if (hasExcessParens(source)) { |
|
report(source); |
|
} |
|
}, |
|
|
|
LogicalExpression: checkBinaryLogical, |
|
|
|
MemberExpression(node) { |
|
const shouldAllowWrapOnce = isMemberExpInNewCallee(node) && |
|
doesMemberExpressionContainCallExpression(node); |
|
const nodeObjHasExcessParens = shouldAllowWrapOnce |
|
? hasDoubleExcessParens(node.object) |
|
: hasExcessParens(node.object) && |
|
!( |
|
isImmediateFunctionPrototypeMethodCall(node.parent) && |
|
node.parent.callee === node && |
|
IGNORE_FUNCTION_PROTOTYPE_METHODS |
|
); |
|
|
|
if ( |
|
nodeObjHasExcessParens && |
|
precedence(node.object) >= precedence(node) && |
|
( |
|
node.computed || |
|
!( |
|
astUtils.isDecimalInteger(node.object) || |
|
|
|
// RegExp literal is allowed to have parens (#1589) |
|
(node.object.type === "Literal" && node.object.regex) |
|
) |
|
) |
|
) { |
|
report(node.object); |
|
} |
|
|
|
if (nodeObjHasExcessParens && |
|
node.object.type === "CallExpression" |
|
) { |
|
report(node.object); |
|
} |
|
|
|
if (nodeObjHasExcessParens && |
|
!IGNORE_NEW_IN_MEMBER_EXPR && |
|
node.object.type === "NewExpression" && |
|
isNewExpressionWithParens(node.object)) { |
|
report(node.object); |
|
} |
|
|
|
if (nodeObjHasExcessParens && |
|
node.optional && |
|
node.object.type === "ChainExpression" |
|
) { |
|
report(node.object); |
|
} |
|
|
|
if (node.computed && hasExcessParens(node.property)) { |
|
report(node.property); |
|
} |
|
}, |
|
|
|
"MethodDefinition[computed=true]"(node) { |
|
if (hasExcessParensWithPrecedence(node.key, PRECEDENCE_OF_ASSIGNMENT_EXPR)) { |
|
report(node.key); |
|
} |
|
}, |
|
|
|
NewExpression: checkCallNew, |
|
|
|
ObjectExpression(node) { |
|
node.properties |
|
.filter(property => property.value && hasExcessParensWithPrecedence(property.value, PRECEDENCE_OF_ASSIGNMENT_EXPR)) |
|
.forEach(property => report(property.value)); |
|
}, |
|
|
|
ObjectPattern(node) { |
|
node.properties |
|
.filter(property => { |
|
const value = property.value; |
|
|
|
return canBeAssignmentTarget(value) && hasExcessParens(value); |
|
}).forEach(property => report(property.value)); |
|
}, |
|
|
|
Property(node) { |
|
if (node.computed) { |
|
const { key } = node; |
|
|
|
if (key && hasExcessParensWithPrecedence(key, PRECEDENCE_OF_ASSIGNMENT_EXPR)) { |
|
report(key); |
|
} |
|
} |
|
}, |
|
|
|
PropertyDefinition(node) { |
|
if (node.computed && hasExcessParensWithPrecedence(node.key, PRECEDENCE_OF_ASSIGNMENT_EXPR)) { |
|
report(node.key); |
|
} |
|
|
|
if (node.value && hasExcessParensWithPrecedence(node.value, PRECEDENCE_OF_ASSIGNMENT_EXPR)) { |
|
report(node.value); |
|
} |
|
}, |
|
|
|
RestElement(node) { |
|
const argument = node.argument; |
|
|
|
if (canBeAssignmentTarget(argument) && hasExcessParens(argument)) { |
|
report(argument); |
|
} |
|
}, |
|
|
|
ReturnStatement(node) { |
|
const returnToken = sourceCode.getFirstToken(node); |
|
|
|
if (isReturnAssignException(node)) { |
|
return; |
|
} |
|
|
|
if (node.argument && |
|
hasExcessParensNoLineTerminator(returnToken, node.argument) && |
|
|
|
// RegExp literal is allowed to have parens (#1589) |
|
!(node.argument.type === "Literal" && node.argument.regex)) { |
|
report(node.argument); |
|
} |
|
}, |
|
|
|
SequenceExpression(node) { |
|
const precedenceOfNode = precedence(node); |
|
|
|
node.expressions |
|
.filter(e => hasExcessParensWithPrecedence(e, precedenceOfNode)) |
|
.forEach(report); |
|
}, |
|
|
|
SwitchCase(node) { |
|
if (node.test && hasExcessParens(node.test)) { |
|
report(node.test); |
|
} |
|
}, |
|
|
|
SwitchStatement(node) { |
|
if (hasExcessParens(node.discriminant)) { |
|
report(node.discriminant); |
|
} |
|
}, |
|
|
|
ThrowStatement(node) { |
|
const throwToken = sourceCode.getFirstToken(node); |
|
|
|
if (hasExcessParensNoLineTerminator(throwToken, node.argument)) { |
|
report(node.argument); |
|
} |
|
}, |
|
|
|
UnaryExpression: checkArgumentWithPrecedence, |
|
UpdateExpression(node) { |
|
if (node.prefix) { |
|
checkArgumentWithPrecedence(node); |
|
} else { |
|
const { argument } = node; |
|
const operatorToken = sourceCode.getLastToken(node); |
|
|
|
if (argument.loc.end.line === operatorToken.loc.start.line) { |
|
checkArgumentWithPrecedence(node); |
|
} else { |
|
if (hasDoubleExcessParens(argument)) { |
|
report(argument); |
|
} |
|
} |
|
} |
|
}, |
|
AwaitExpression: checkArgumentWithPrecedence, |
|
|
|
VariableDeclarator(node) { |
|
if ( |
|
node.init && hasExcessParensWithPrecedence(node.init, PRECEDENCE_OF_ASSIGNMENT_EXPR) && |
|
|
|
// RegExp literal is allowed to have parens (#1589) |
|
!(node.init.type === "Literal" && node.init.regex) |
|
) { |
|
report(node.init); |
|
} |
|
}, |
|
|
|
WhileStatement(node) { |
|
if (hasExcessParens(node.test) && !isCondAssignException(node)) { |
|
report(node.test); |
|
} |
|
}, |
|
|
|
WithStatement(node) { |
|
if (hasExcessParens(node.object)) { |
|
report(node.object); |
|
} |
|
}, |
|
|
|
YieldExpression(node) { |
|
if (node.argument) { |
|
const yieldToken = sourceCode.getFirstToken(node); |
|
|
|
if ((precedence(node.argument) >= precedence(node) && |
|
hasExcessParensNoLineTerminator(yieldToken, node.argument)) || |
|
hasDoubleExcessParens(node.argument)) { |
|
report(node.argument); |
|
} |
|
} |
|
}, |
|
|
|
ClassDeclaration: checkClass, |
|
ClassExpression: checkClass, |
|
|
|
SpreadElement: checkSpreadOperator, |
|
SpreadProperty: checkSpreadOperator, |
|
ExperimentalSpreadProperty: checkSpreadOperator, |
|
|
|
TemplateLiteral(node) { |
|
node.expressions |
|
.filter(e => e && hasExcessParens(e)) |
|
.forEach(report); |
|
}, |
|
|
|
AssignmentPattern(node) { |
|
const { left, right } = node; |
|
|
|
if (canBeAssignmentTarget(left) && hasExcessParens(left)) { |
|
report(left); |
|
} |
|
|
|
if (right && hasExcessParensWithPrecedence(right, PRECEDENCE_OF_ASSIGNMENT_EXPR)) { |
|
report(right); |
|
} |
|
} |
|
}; |
|
|
|
} |
|
};
|
|
|