ifc-language-server/node_modules/eslint/lib/rules/no-useless-concat.js
Ryan Schultz 8afacf268a Implemented a working Language Server Protocol (LSP) for IFC files with:
- Hover provider showing entity information and type
- Go-to-definition (F12) for entity references
- Basic IFC file validation (ISO-10303-21 header check)
- Entity parsing with regex-based detection
- Proper CommonJS module system (avoiding ES module issues)

This replaces the broken baseline from ifc-developer-tools which had:
- Non-functional ES module configuration
- Circular dependency issues
- Parser crashes
- Non-working PositionVisitor

Built on Microsoft's LSP example template for a clean, maintainable foundation.

Next: Add hierarchical entity dependency tree in hover tooltip."
2025-12-07 10:20:07 -06:00

121 lines
2.9 KiB
JavaScript

/**
* @fileoverview disallow unnecessary concatenation of template strings
* @author Henry Zhu
*/
"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 === "+";
}
/**
* Checks if the given token is a `+` token or not.
* @param {Token} token The token to check.
* @returns {boolean} `true` if the token is a `+` token.
*/
function isConcatOperatorToken(token) {
return token.value === "+" && token.type === "Punctuator";
}
/**
* Get's the right most node on the left side of a BinaryExpression with + operator.
* @param {ASTNode} node A BinaryExpression node to check.
* @returns {ASTNode} node
*/
function getLeft(node) {
let left = node.left;
while (isConcatenation(left)) {
left = left.right;
}
return left;
}
/**
* Get's the left most node on the right side of a BinaryExpression with + operator.
* @param {ASTNode} node A BinaryExpression node to check.
* @returns {ASTNode} node
*/
function getRight(node) {
let right = node.right;
while (isConcatenation(right)) {
right = right.left;
}
return right;
}
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
/** @type {import('../types').Rule.RuleModule} */
module.exports = {
meta: {
type: "suggestion",
docs: {
description:
"Disallow unnecessary concatenation of literals or template literals",
recommended: false,
frozen: true,
url: "https://eslint.org/docs/latest/rules/no-useless-concat",
},
schema: [],
messages: {
unexpectedConcat: "Unexpected string concatenation of literals.",
},
},
create(context) {
const sourceCode = context.sourceCode;
return {
BinaryExpression(node) {
// check if not concatenation
if (node.operator !== "+") {
return;
}
// account for the `foo + "a" + "b"` case
const left = getLeft(node);
const right = getRight(node);
if (
astUtils.isStringLiteral(left) &&
astUtils.isStringLiteral(right) &&
astUtils.isTokenOnSameLine(left, right)
) {
const operatorToken = sourceCode.getFirstTokenBetween(
left,
right,
isConcatOperatorToken,
);
context.report({
node,
loc: operatorToken.loc,
messageId: "unexpectedConcat",
});
}
},
};
},
};