diff --git a/.eslintrc b/.eslintrc index b48f2277c83212..542be9ceaa749d 100644 --- a/.eslintrc +++ b/.eslintrc @@ -85,6 +85,7 @@ rules: prefer-const: 2 # Custom rules in tools/eslint-rules + align-function-arguments: 2 align-multiline-assignment: 2 assert-fail-single-argument: 2 new-with-error: [2, "Error", "RangeError", "TypeError", "SyntaxError", "ReferenceError"] diff --git a/tools/eslint-rules/align-function-arguments.js b/tools/eslint-rules/align-function-arguments.js new file mode 100644 index 00000000000000..a8cd71660d7d60 --- /dev/null +++ b/tools/eslint-rules/align-function-arguments.js @@ -0,0 +1,70 @@ +/** + * @fileoverview Align arguments in multiline function calls + * @author Rich Trott + */ +'use strict'; + +//------------------------------------------------------------------------------ +// Rule Definition +//------------------------------------------------------------------------------ + +function checkArgumentAlignment(context, node) { + + function isNodeFirstInLine(node, byEndLocation) { + const firstToken = byEndLocation === true ? context.getLastToken(node, 1) : + context.getTokenBefore(node); + const startLine = byEndLocation === true ? node.loc.end.line : + node.loc.start.line; + const endLine = firstToken ? firstToken.loc.end.line : -1; + + return startLine !== endLine; + } + + if (node.arguments.length === 0) + return; + + var msg = ''; + const first = node.arguments[0]; + var currentLine = first.loc.start.line; + const firstColumn = first.loc.start.column; + + const ignoreTypes = [ + 'ArrowFunctionExpression', + 'CallExpression', + 'FunctionExpression', + 'ObjectExpression', + 'TemplateLiteral' + ]; + + const args = node.arguments; + + // For now, don't bother trying to validate potentially complicating things + // like closures. Different people will have very different ideas and it's + // probably best to implement configuration options. + if (args.some((node) => { return ignoreTypes.indexOf(node.type) !== -1; })) { + return; + } + + if (!isNodeFirstInLine(node)) { + return; + } + + args.slice(1).forEach((argument) => { + if (argument.loc.start.line === currentLine + 1) { + if (argument.loc.start.column !== firstColumn) { + msg = 'Function called with argument in column ' + + `${argument.loc.start.column}, expected in ${firstColumn}`; + } + } + currentLine = argument.loc.start.line; + }); + + if (msg) + context.report(node, msg); +} + +module.exports = function(context) { + return { + 'CallExpression': (node) => checkArgumentAlignment(context, node) + }; +};