odin-javascript-exercises/node_modules/eslint/lib/rules/implicit-arrow-linebreak.js
2017-12-15 12:56:14 -06:00

86 lines
3 KiB
JavaScript

/**
* @fileoverview enforce the location of arrow function bodies
* @author Sharmila Jesupaul
*/
"use strict";
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
module.exports = {
meta: {
docs: {
description: "enforce the location of arrow function bodies",
category: "Stylistic Issues",
recommended: false
},
fixable: "whitespace",
schema: [
{
enum: ["beside", "below"]
}
]
},
create(context) {
const sourceCode = context.getSourceCode();
//----------------------------------------------------------------------
// Helpers
//----------------------------------------------------------------------
/**
* Gets the applicable preference for a particular keyword
* @returns {string} The applicable option for the keyword, e.g. 'beside'
*/
function getOption() {
return context.options[0] || "beside";
}
/**
* Validates the location of an arrow function body
* @param {ASTNode} node The arrow function body
* @param {string} keywordName The applicable keyword name for the arrow function body
* @returns {void}
*/
function validateExpression(node) {
const option = getOption();
let tokenBefore = sourceCode.getTokenBefore(node.body);
const hasParens = tokenBefore.value === "(";
if (node.type === "BlockStatement") {
return;
}
let fixerTarget = node.body;
if (hasParens) {
// Gets the first token before the function body that is not an open paren
tokenBefore = sourceCode.getTokenBefore(node.body, token => token.value !== "(");
fixerTarget = sourceCode.getTokenAfter(tokenBefore);
}
if (tokenBefore.loc.end.line === fixerTarget.loc.start.line && option === "below") {
context.report({
node: fixerTarget,
message: "Expected a linebreak before this expression.",
fix: fixer => fixer.insertTextBefore(fixerTarget, "\n")
});
} else if (tokenBefore.loc.end.line !== fixerTarget.loc.start.line && option === "beside") {
context.report({
node: fixerTarget,
message: "Expected no linebreak before this expression.",
fix: fixer => fixer.replaceTextRange([tokenBefore.range[1], fixerTarget.range[0]], " ")
});
}
}
//----------------------------------------------------------------------
// Public
//----------------------------------------------------------------------
return {
ArrowFunctionExpression: node => validateExpression(node)
};
}
};