odin-javascript-exercises/node_modules/eslint/lib/rules/no-useless-rename.js
2017-12-15 12:56:14 -06:00

147 lines
4.9 KiB
JavaScript

/**
* @fileoverview Disallow renaming import, export, and destructured assignments to the same name.
* @author Kai Cataldo
*/
"use strict";
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
module.exports = {
meta: {
docs: {
description: "disallow renaming import, export, and destructured assignments to the same name",
category: "ECMAScript 6",
recommended: false
},
fixable: "code",
schema: [
{
type: "object",
properties: {
ignoreDestructuring: { type: "boolean" },
ignoreImport: { type: "boolean" },
ignoreExport: { type: "boolean" }
},
additionalProperties: false
}
]
},
create(context) {
const options = context.options[0] || {},
ignoreDestructuring = options.ignoreDestructuring === true,
ignoreImport = options.ignoreImport === true,
ignoreExport = options.ignoreExport === true;
//--------------------------------------------------------------------------
// Helpers
//--------------------------------------------------------------------------
/**
* Reports error for unnecessarily renamed assignments
* @param {ASTNode} node - node to report
* @param {ASTNode} initial - node with initial name value
* @param {ASTNode} result - node with new name value
* @param {string} type - the type of the offending node
* @returns {void}
*/
function reportError(node, initial, result, type) {
const name = initial.type === "Identifier" ? initial.name : initial.value;
return context.report({
node,
message: "{{type}} {{name}} unnecessarily renamed.",
data: {
name,
type
},
fix(fixer) {
return fixer.replaceTextRange([
initial.range[0],
result.range[1]
], name);
}
});
}
/**
* Checks whether a destructured assignment is unnecessarily renamed
* @param {ASTNode} node - node to check
* @returns {void}
*/
function checkDestructured(node) {
if (ignoreDestructuring) {
return;
}
const properties = node.properties;
for (let i = 0; i < properties.length; i++) {
if (properties[i].shorthand) {
continue;
}
/**
* If an ObjectPattern property is computed, we have no idea
* if a rename is useless or not. If an ObjectPattern property
* lacks a key, it is likely an ExperimentalRestProperty and
* so there is no "renaming" occurring here.
*/
if (properties[i].computed || !properties[i].key) {
continue;
}
if (properties[i].key.type === "Identifier" && properties[i].key.name === properties[i].value.name ||
properties[i].key.type === "Literal" && properties[i].key.value === properties[i].value.name) {
reportError(properties[i], properties[i].key, properties[i].value, "Destructuring assignment");
}
}
}
/**
* Checks whether an import is unnecessarily renamed
* @param {ASTNode} node - node to check
* @returns {void}
*/
function checkImport(node) {
if (ignoreImport) {
return;
}
if (node.imported.name === node.local.name &&
node.imported.range[0] !== node.local.range[0]) {
reportError(node, node.imported, node.local, "Import");
}
}
/**
* Checks whether an export is unnecessarily renamed
* @param {ASTNode} node - node to check
* @returns {void}
*/
function checkExport(node) {
if (ignoreExport) {
return;
}
if (node.local.name === node.exported.name &&
node.local.range[0] !== node.exported.range[0]) {
reportError(node, node.local, node.exported, "Export");
}
}
//--------------------------------------------------------------------------
// Public
//--------------------------------------------------------------------------
return {
ObjectPattern: checkDestructured,
ImportSpecifier: checkImport,
ExportSpecifier: checkExport
};
}
};