odin-javascript-exercises/node_modules/eslint/lib/rules/newline-per-chained-call.js
2017-12-15 12:56:14 -06:00

103 lines
3.4 KiB
JavaScript

/**
* @fileoverview Rule to ensure newline per method call when chaining calls
* @author Rajendra Patil
* @author Burak Yigit Kaya
*/
"use strict";
const astUtils = require("../ast-utils");
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
module.exports = {
meta: {
docs: {
description: "require a newline after each call in a method chain",
category: "Stylistic Issues",
recommended: false
},
fixable: "whitespace",
schema: [{
type: "object",
properties: {
ignoreChainWithDepth: {
type: "integer",
minimum: 1,
maximum: 10
}
},
additionalProperties: false
}]
},
create(context) {
const options = context.options[0] || {},
ignoreChainWithDepth = options.ignoreChainWithDepth || 2;
const sourceCode = context.getSourceCode();
/**
* Get the prefix of a given MemberExpression node.
* If the MemberExpression node is a computed value it returns a
* left bracket. If not it returns a period.
*
* @param {ASTNode} node - A MemberExpression node to get
* @returns {string} The prefix of the node.
*/
function getPrefix(node) {
return node.computed ? "[" : ".";
}
/**
* Gets the property text of a given MemberExpression node.
* If the text is multiline, this returns only the first line.
*
* @param {ASTNode} node - A MemberExpression node to get.
* @returns {string} The property text of the node.
*/
function getPropertyText(node) {
const prefix = getPrefix(node);
const lines = sourceCode.getText(node.property).split(astUtils.LINEBREAK_MATCHER);
const suffix = node.computed && lines.length === 1 ? "]" : "";
return prefix + lines[0] + suffix;
}
return {
"CallExpression:exit"(node) {
if (!node.callee || node.callee.type !== "MemberExpression") {
return;
}
const callee = node.callee;
let parent = callee.object;
let depth = 1;
while (parent && parent.callee) {
depth += 1;
parent = parent.callee.object;
}
if (depth > ignoreChainWithDepth && astUtils.isTokenOnSameLine(callee.object, callee.property)) {
context.report({
node: callee.property,
loc: callee.property.loc.start,
message: "Expected line break before `{{callee}}`.",
data: {
callee: getPropertyText(callee)
},
fix(fixer) {
const firstTokenAfterObject = sourceCode.getTokenAfter(callee.object, astUtils.isNotClosingParenToken);
return fixer.insertTextBefore(firstTokenAfterObject, "\n");
}
});
}
}
};
}
};