Skip to content
Permalink
9bfb9ba527
Switch branches/tags

Name already in use

A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?
Go to file
 
 
Cannot retrieve contributors at this time
164 lines (142 sloc) 5.78 KB
/**
* @fileoverview Rule to validate spacing before function paren.
* @author Mathias Schreck <https://github.com/lo1tuma>
*/
"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 spacing before `function` definition opening parenthesis",
recommended: false,
url: "https://eslint.org/docs/latest/rules/space-before-function-paren"
},
fixable: "whitespace",
schema: [
{
oneOf: [
{
enum: ["always", "never"]
},
{
type: "object",
properties: {
anonymous: {
enum: ["always", "never", "ignore"]
},
named: {
enum: ["always", "never", "ignore"]
},
asyncArrow: {
enum: ["always", "never", "ignore"]
}
},
additionalProperties: false
}
]
}
],
messages: {
unexpectedSpace: "Unexpected space before function parentheses.",
missingSpace: "Missing space before function parentheses."
}
},
create(context) {
const sourceCode = context.sourceCode;
const baseConfig = typeof context.options[0] === "string" ? context.options[0] : "always";
const overrideConfig = typeof context.options[0] === "object" ? context.options[0] : {};
/**
* Determines whether a function has a name.
* @param {ASTNode} node The function node.
* @returns {boolean} Whether the function has a name.
*/
function isNamedFunction(node) {
if (node.id) {
return true;
}
const parent = node.parent;
return parent.type === "MethodDefinition" ||
(parent.type === "Property" &&
(
parent.kind === "get" ||
parent.kind === "set" ||
parent.method
)
);
}
/**
* Gets the config for a given function
* @param {ASTNode} node The function node
* @returns {string} "always", "never", or "ignore"
*/
function getConfigForFunction(node) {
if (node.type === "ArrowFunctionExpression") {
// Always ignore non-async functions and arrow functions without parens, e.g. async foo => bar
if (node.async && astUtils.isOpeningParenToken(sourceCode.getFirstToken(node, { skip: 1 }))) {
return overrideConfig.asyncArrow || baseConfig;
}
} else if (isNamedFunction(node)) {
return overrideConfig.named || baseConfig;
// `generator-star-spacing` should warn anonymous generators. E.g. `function* () {}`
} else if (!node.generator) {
return overrideConfig.anonymous || baseConfig;
}
return "ignore";
}
/**
* Checks the parens of a function node
* @param {ASTNode} node A function node
* @returns {void}
*/
function checkFunction(node) {
const functionConfig = getConfigForFunction(node);
if (functionConfig === "ignore") {
return;
}
const rightToken = sourceCode.getFirstToken(node, astUtils.isOpeningParenToken);
const leftToken = sourceCode.getTokenBefore(rightToken);
const hasSpacing = sourceCode.isSpaceBetweenTokens(leftToken, rightToken);
if (hasSpacing && functionConfig === "never") {
context.report({
node,
loc: {
start: leftToken.loc.end,
end: rightToken.loc.start
},
messageId: "unexpectedSpace",
fix(fixer) {
const comments = sourceCode.getCommentsBefore(rightToken);
// Don't fix anything if there's a single line comment between the left and the right token
if (comments.some(comment => comment.type === "Line")) {
return null;
}
return fixer.replaceTextRange(
[leftToken.range[1], rightToken.range[0]],
comments.reduce((text, comment) => text + sourceCode.getText(comment), "")
);
}
});
} else if (!hasSpacing && functionConfig === "always") {
context.report({
node,
loc: rightToken.loc,
messageId: "missingSpace",
fix: fixer => fixer.insertTextAfter(leftToken, " ")
});
}
}
return {
ArrowFunctionExpression: checkFunction,
FunctionDeclaration: checkFunction,
FunctionExpression: checkFunction
};
}
};