/** * @fileoverview Rule to ensure newline per method call when chaining calls * @author Rajendra Patil * @author Burak Yigit Kaya */ "use strict"; //------------------------------------------------------------------------------ // Rule Definition //------------------------------------------------------------------------------ module.exports = { meta: { docs: { description: "require a newline after each call in a method chain", category: "Stylistic Issues", recommended: false }, 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(); /** * 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 = node.computed ? "[" : "."; const lines = sourceCode.getText(node.property).split(/\r\n|\r|\n/g); 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 && callee.property.loc.start.line === callee.object.loc.end.line) { context.report({ node: callee.property, loc: callee.property.loc.start, message: "Expected line break before `{{callee}}`.", data: { callee: getPropertyText(callee) } }); } } }; } };