mirror of
https://github.com/idanoo/GoScrobble.git
synced 2024-11-25 09:55:15 +00:00
276 lines
11 KiB
JavaScript
276 lines
11 KiB
JavaScript
/**
|
||
* @fileoverview A rule to suggest using template literals instead of string concatenation.
|
||
* @author Toru Nagashima
|
||
*/
|
||
|
||
"use strict";
|
||
|
||
//------------------------------------------------------------------------------
|
||
// Requirements
|
||
//------------------------------------------------------------------------------
|
||
|
||
const astUtils = require("./utils/ast-utils");
|
||
|
||
//------------------------------------------------------------------------------
|
||
// Helpers
|
||
//------------------------------------------------------------------------------
|
||
|
||
/**
|
||
* Checks whether or not a given node is a concatenation.
|
||
* @param {ASTNode} node A node to check.
|
||
* @returns {boolean} `true` if the node is a concatenation.
|
||
*/
|
||
function isConcatenation(node) {
|
||
return node.type === "BinaryExpression" && node.operator === "+";
|
||
}
|
||
|
||
/**
|
||
* Gets the top binary expression node for concatenation in parents of a given node.
|
||
* @param {ASTNode} node A node to get.
|
||
* @returns {ASTNode} the top binary expression node in parents of a given node.
|
||
*/
|
||
function getTopConcatBinaryExpression(node) {
|
||
let currentNode = node;
|
||
|
||
while (isConcatenation(currentNode.parent)) {
|
||
currentNode = currentNode.parent;
|
||
}
|
||
return currentNode;
|
||
}
|
||
|
||
/**
|
||
* Checks whether or not a node contains a string literal with an octal or non-octal decimal escape sequence
|
||
* @param {ASTNode} node A node to check
|
||
* @returns {boolean} `true` if at least one string literal within the node contains
|
||
* an octal or non-octal decimal escape sequence
|
||
*/
|
||
function hasOctalOrNonOctalDecimalEscapeSequence(node) {
|
||
if (isConcatenation(node)) {
|
||
return (
|
||
hasOctalOrNonOctalDecimalEscapeSequence(node.left) ||
|
||
hasOctalOrNonOctalDecimalEscapeSequence(node.right)
|
||
);
|
||
}
|
||
|
||
// No need to check TemplateLiterals – would throw parsing error
|
||
if (node.type === "Literal" && typeof node.value === "string") {
|
||
return astUtils.hasOctalOrNonOctalDecimalEscapeSequence(node.raw);
|
||
}
|
||
|
||
return false;
|
||
}
|
||
|
||
/**
|
||
* Checks whether or not a given binary expression has string literals.
|
||
* @param {ASTNode} node A node to check.
|
||
* @returns {boolean} `true` if the node has string literals.
|
||
*/
|
||
function hasStringLiteral(node) {
|
||
if (isConcatenation(node)) {
|
||
|
||
// `left` is deeper than `right` normally.
|
||
return hasStringLiteral(node.right) || hasStringLiteral(node.left);
|
||
}
|
||
return astUtils.isStringLiteral(node);
|
||
}
|
||
|
||
/**
|
||
* Checks whether or not a given binary expression has non string literals.
|
||
* @param {ASTNode} node A node to check.
|
||
* @returns {boolean} `true` if the node has non string literals.
|
||
*/
|
||
function hasNonStringLiteral(node) {
|
||
if (isConcatenation(node)) {
|
||
|
||
// `left` is deeper than `right` normally.
|
||
return hasNonStringLiteral(node.right) || hasNonStringLiteral(node.left);
|
||
}
|
||
return !astUtils.isStringLiteral(node);
|
||
}
|
||
|
||
/**
|
||
* Determines whether a given node will start with a template curly expression (`${}`) when being converted to a template literal.
|
||
* @param {ASTNode} node The node that will be fixed to a template literal
|
||
* @returns {boolean} `true` if the node will start with a template curly.
|
||
*/
|
||
function startsWithTemplateCurly(node) {
|
||
if (node.type === "BinaryExpression") {
|
||
return startsWithTemplateCurly(node.left);
|
||
}
|
||
if (node.type === "TemplateLiteral") {
|
||
return node.expressions.length && node.quasis.length && node.quasis[0].range[0] === node.quasis[0].range[1];
|
||
}
|
||
return node.type !== "Literal" || typeof node.value !== "string";
|
||
}
|
||
|
||
/**
|
||
* Determines whether a given node end with a template curly expression (`${}`) when being converted to a template literal.
|
||
* @param {ASTNode} node The node that will be fixed to a template literal
|
||
* @returns {boolean} `true` if the node will end with a template curly.
|
||
*/
|
||
function endsWithTemplateCurly(node) {
|
||
if (node.type === "BinaryExpression") {
|
||
return startsWithTemplateCurly(node.right);
|
||
}
|
||
if (node.type === "TemplateLiteral") {
|
||
return node.expressions.length && node.quasis.length && node.quasis[node.quasis.length - 1].range[0] === node.quasis[node.quasis.length - 1].range[1];
|
||
}
|
||
return node.type !== "Literal" || typeof node.value !== "string";
|
||
}
|
||
|
||
//------------------------------------------------------------------------------
|
||
// Rule Definition
|
||
//------------------------------------------------------------------------------
|
||
|
||
module.exports = {
|
||
meta: {
|
||
type: "suggestion",
|
||
|
||
docs: {
|
||
description: "require template literals instead of string concatenation",
|
||
category: "ECMAScript 6",
|
||
recommended: false,
|
||
url: "https://eslint.org/docs/rules/prefer-template"
|
||
},
|
||
|
||
schema: [],
|
||
fixable: "code",
|
||
|
||
messages: {
|
||
unexpectedStringConcatenation: "Unexpected string concatenation."
|
||
}
|
||
},
|
||
|
||
create(context) {
|
||
const sourceCode = context.getSourceCode();
|
||
let done = Object.create(null);
|
||
|
||
/**
|
||
* Gets the non-token text between two nodes, ignoring any other tokens that appear between the two tokens.
|
||
* @param {ASTNode} node1 The first node
|
||
* @param {ASTNode} node2 The second node
|
||
* @returns {string} The text between the nodes, excluding other tokens
|
||
*/
|
||
function getTextBetween(node1, node2) {
|
||
const allTokens = [node1].concat(sourceCode.getTokensBetween(node1, node2)).concat(node2);
|
||
const sourceText = sourceCode.getText();
|
||
|
||
return allTokens.slice(0, -1).reduce((accumulator, token, index) => accumulator + sourceText.slice(token.range[1], allTokens[index + 1].range[0]), "");
|
||
}
|
||
|
||
/**
|
||
* Returns a template literal form of the given node.
|
||
* @param {ASTNode} currentNode A node that should be converted to a template literal
|
||
* @param {string} textBeforeNode Text that should appear before the node
|
||
* @param {string} textAfterNode Text that should appear after the node
|
||
* @returns {string} A string form of this node, represented as a template literal
|
||
*/
|
||
function getTemplateLiteral(currentNode, textBeforeNode, textAfterNode) {
|
||
if (currentNode.type === "Literal" && typeof currentNode.value === "string") {
|
||
|
||
/*
|
||
* If the current node is a string literal, escape any instances of ${ or ` to prevent them from being interpreted
|
||
* as a template placeholder. However, if the code already contains a backslash before the ${ or `
|
||
* for some reason, don't add another backslash, because that would change the meaning of the code (it would cause
|
||
* an actual backslash character to appear before the dollar sign).
|
||
*/
|
||
return `\`${currentNode.raw.slice(1, -1).replace(/\\*(\$\{|`)/gu, matched => {
|
||
if (matched.lastIndexOf("\\") % 2) {
|
||
return `\\${matched}`;
|
||
}
|
||
return matched;
|
||
|
||
// Unescape any quotes that appear in the original Literal that no longer need to be escaped.
|
||
}).replace(new RegExp(`\\\\${currentNode.raw[0]}`, "gu"), currentNode.raw[0])}\``;
|
||
}
|
||
|
||
if (currentNode.type === "TemplateLiteral") {
|
||
return sourceCode.getText(currentNode);
|
||
}
|
||
|
||
if (isConcatenation(currentNode) && hasStringLiteral(currentNode) && hasNonStringLiteral(currentNode)) {
|
||
const plusSign = sourceCode.getFirstTokenBetween(currentNode.left, currentNode.right, token => token.value === "+");
|
||
const textBeforePlus = getTextBetween(currentNode.left, plusSign);
|
||
const textAfterPlus = getTextBetween(plusSign, currentNode.right);
|
||
const leftEndsWithCurly = endsWithTemplateCurly(currentNode.left);
|
||
const rightStartsWithCurly = startsWithTemplateCurly(currentNode.right);
|
||
|
||
if (leftEndsWithCurly) {
|
||
|
||
// If the left side of the expression ends with a template curly, add the extra text to the end of the curly bracket.
|
||
// `foo${bar}` /* comment */ + 'baz' --> `foo${bar /* comment */ }${baz}`
|
||
return getTemplateLiteral(currentNode.left, textBeforeNode, textBeforePlus + textAfterPlus).slice(0, -1) +
|
||
getTemplateLiteral(currentNode.right, null, textAfterNode).slice(1);
|
||
}
|
||
if (rightStartsWithCurly) {
|
||
|
||
// Otherwise, if the right side of the expression starts with a template curly, add the text there.
|
||
// 'foo' /* comment */ + `${bar}baz` --> `foo${ /* comment */ bar}baz`
|
||
return getTemplateLiteral(currentNode.left, textBeforeNode, null).slice(0, -1) +
|
||
getTemplateLiteral(currentNode.right, textBeforePlus + textAfterPlus, textAfterNode).slice(1);
|
||
}
|
||
|
||
/*
|
||
* Otherwise, these nodes should not be combined into a template curly, since there is nowhere to put
|
||
* the text between them.
|
||
*/
|
||
return `${getTemplateLiteral(currentNode.left, textBeforeNode, null)}${textBeforePlus}+${textAfterPlus}${getTemplateLiteral(currentNode.right, textAfterNode, null)}`;
|
||
}
|
||
|
||
return `\`\${${textBeforeNode || ""}${sourceCode.getText(currentNode)}${textAfterNode || ""}}\``;
|
||
}
|
||
|
||
/**
|
||
* Returns a fixer object that converts a non-string binary expression to a template literal
|
||
* @param {SourceCodeFixer} fixer The fixer object
|
||
* @param {ASTNode} node A node that should be converted to a template literal
|
||
* @returns {Object} A fix for this binary expression
|
||
*/
|
||
function fixNonStringBinaryExpression(fixer, node) {
|
||
const topBinaryExpr = getTopConcatBinaryExpression(node.parent);
|
||
|
||
if (hasOctalOrNonOctalDecimalEscapeSequence(topBinaryExpr)) {
|
||
return null;
|
||
}
|
||
|
||
return fixer.replaceText(topBinaryExpr, getTemplateLiteral(topBinaryExpr, null, null));
|
||
}
|
||
|
||
/**
|
||
* Reports if a given node is string concatenation with non string literals.
|
||
* @param {ASTNode} node A node to check.
|
||
* @returns {void}
|
||
*/
|
||
function checkForStringConcat(node) {
|
||
if (!astUtils.isStringLiteral(node) || !isConcatenation(node.parent)) {
|
||
return;
|
||
}
|
||
|
||
const topBinaryExpr = getTopConcatBinaryExpression(node.parent);
|
||
|
||
// Checks whether or not this node had been checked already.
|
||
if (done[topBinaryExpr.range[0]]) {
|
||
return;
|
||
}
|
||
done[topBinaryExpr.range[0]] = true;
|
||
|
||
if (hasNonStringLiteral(topBinaryExpr)) {
|
||
context.report({
|
||
node: topBinaryExpr,
|
||
messageId: "unexpectedStringConcatenation",
|
||
fix: fixer => fixNonStringBinaryExpression(fixer, node)
|
||
});
|
||
}
|
||
}
|
||
|
||
return {
|
||
Program() {
|
||
done = Object.create(null);
|
||
},
|
||
|
||
Literal: checkForStringConcat,
|
||
TemplateLiteral: checkForStringConcat
|
||
};
|
||
}
|
||
};
|