Current File : /var/www/html/node_modules/eslint/lib/rules/operator-linebreak.js
/**
* @fileoverview Operator linebreak - enforces operator linebreak style of two types: after and before
* @author Benoît Zugmeyer
*/
"use strict";
//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------
const astUtils = require("./utils/ast-utils");
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
/** @type {import('../shared/types').Rule} */
module.exports = {
meta: {
type: "layout",
docs: {
description: "enforce consistent linebreak style for operators",
recommended: false,
url: "https://eslint.org/docs/rules/operator-linebreak"
},
schema: [
{
enum: ["after", "before", "none", null]
},
{
type: "object",
properties: {
overrides: {
type: "object",
additionalProperties: {
enum: ["after", "before", "none", "ignore"]
}
}
},
additionalProperties: false
}
],
fixable: "code",
messages: {
operatorAtBeginning: "'{{operator}}' should be placed at the beginning of the line.",
operatorAtEnd: "'{{operator}}' should be placed at the end of the line.",
badLinebreak: "Bad line breaking before and after '{{operator}}'.",
noLinebreak: "There should be no line break before or after '{{operator}}'."
}
},
create(context) {
const usedDefaultGlobal = !context.options[0];
const globalStyle = context.options[0] || "after";
const options = context.options[1] || {};
const styleOverrides = options.overrides ? Object.assign({}, options.overrides) : {};
if (usedDefaultGlobal && !styleOverrides["?"]) {
styleOverrides["?"] = "before";
}
if (usedDefaultGlobal && !styleOverrides[":"]) {
styleOverrides[":"] = "before";
}
const sourceCode = context.getSourceCode();
//--------------------------------------------------------------------------
// Helpers
//--------------------------------------------------------------------------
/**
* Gets a fixer function to fix rule issues
* @param {Token} operatorToken The operator token of an expression
* @param {string} desiredStyle The style for the rule. One of 'before', 'after', 'none'
* @returns {Function} A fixer function
*/
function getFixer(operatorToken, desiredStyle) {
return fixer => {
const tokenBefore = sourceCode.getTokenBefore(operatorToken);
const tokenAfter = sourceCode.getTokenAfter(operatorToken);
const textBefore = sourceCode.text.slice(tokenBefore.range[1], operatorToken.range[0]);
const textAfter = sourceCode.text.slice(operatorToken.range[1], tokenAfter.range[0]);
const hasLinebreakBefore = !astUtils.isTokenOnSameLine(tokenBefore, operatorToken);
const hasLinebreakAfter = !astUtils.isTokenOnSameLine(operatorToken, tokenAfter);
let newTextBefore, newTextAfter;
if (hasLinebreakBefore !== hasLinebreakAfter && desiredStyle !== "none") {
// If there is a comment before and after the operator, don't do a fix.
if (sourceCode.getTokenBefore(operatorToken, { includeComments: true }) !== tokenBefore &&
sourceCode.getTokenAfter(operatorToken, { includeComments: true }) !== tokenAfter) {
return null;
}
/*
* If there is only one linebreak and it's on the wrong side of the operator, swap the text before and after the operator.
* foo &&
* bar
* would get fixed to
* foo
* && bar
*/
newTextBefore = textAfter;
newTextAfter = textBefore;
} else {
const LINEBREAK_REGEX = astUtils.createGlobalLinebreakMatcher();
// Otherwise, if no linebreak is desired and no comments interfere, replace the linebreaks with empty strings.
newTextBefore = desiredStyle === "before" || textBefore.trim() ? textBefore : textBefore.replace(LINEBREAK_REGEX, "");
newTextAfter = desiredStyle === "after" || textAfter.trim() ? textAfter : textAfter.replace(LINEBREAK_REGEX, "");
// If there was no change (due to interfering comments), don't output a fix.
if (newTextBefore === textBefore && newTextAfter === textAfter) {
return null;
}
}
if (newTextAfter === "" && tokenAfter.type === "Punctuator" && "+-".includes(operatorToken.value) && tokenAfter.value === operatorToken.value) {
// To avoid accidentally creating a ++ or -- operator, insert a space if the operator is a +/- and the following token is a unary +/-.
newTextAfter += " ";
}
return fixer.replaceTextRange([tokenBefore.range[1], tokenAfter.range[0]], newTextBefore + operatorToken.value + newTextAfter);
};
}
/**
* Checks the operator placement
* @param {ASTNode} node The node to check
* @param {ASTNode} rightSide The node that comes after the operator in `node`
* @param {string} operator The operator
* @private
* @returns {void}
*/
function validateNode(node, rightSide, operator) {
/*
* Find the operator token by searching from the right side, because between the left side and the operator
* there could be additional tokens from type annotations. Search specifically for the token which
* value equals the operator, in order to skip possible opening parentheses before the right side node.
*/
const operatorToken = sourceCode.getTokenBefore(rightSide, token => token.value === operator);
const leftToken = sourceCode.getTokenBefore(operatorToken);
const rightToken = sourceCode.getTokenAfter(operatorToken);
const operatorStyleOverride = styleOverrides[operator];
const style = operatorStyleOverride || globalStyle;
const fix = getFixer(operatorToken, style);
// if single line
if (astUtils.isTokenOnSameLine(leftToken, operatorToken) &&
astUtils.isTokenOnSameLine(operatorToken, rightToken)) {
// do nothing.
} else if (operatorStyleOverride !== "ignore" && !astUtils.isTokenOnSameLine(leftToken, operatorToken) &&
!astUtils.isTokenOnSameLine(operatorToken, rightToken)) {
// lone operator
context.report({
node,
loc: operatorToken.loc,
messageId: "badLinebreak",
data: {
operator
},
fix
});
} else if (style === "before" && astUtils.isTokenOnSameLine(leftToken, operatorToken)) {
context.report({
node,
loc: operatorToken.loc,
messageId: "operatorAtBeginning",
data: {
operator
},
fix
});
} else if (style === "after" && astUtils.isTokenOnSameLine(operatorToken, rightToken)) {
context.report({
node,
loc: operatorToken.loc,
messageId: "operatorAtEnd",
data: {
operator
},
fix
});
} else if (style === "none") {
context.report({
node,
loc: operatorToken.loc,
messageId: "noLinebreak",
data: {
operator
},
fix
});
}
}
/**
* Validates a binary expression using `validateNode`
* @param {BinaryExpression|LogicalExpression|AssignmentExpression} node node to be validated
* @returns {void}
*/
function validateBinaryExpression(node) {
validateNode(node, node.right, node.operator);
}
//--------------------------------------------------------------------------
// Public
//--------------------------------------------------------------------------
return {
BinaryExpression: validateBinaryExpression,
LogicalExpression: validateBinaryExpression,
AssignmentExpression: validateBinaryExpression,
VariableDeclarator(node) {
if (node.init) {
validateNode(node, node.init, "=");
}
},
PropertyDefinition(node) {
if (node.value) {
validateNode(node, node.value, "=");
}
},
ConditionalExpression(node) {
validateNode(node, node.consequent, "?");
validateNode(node, node.alternate, ":");
}
};
}
};
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