iptvnator/tools/eslint/generate-max-lines-baseline.mjs

#!/usr/bin/env node

/**
 * Regenerates tools/eslint/max-lines-baseline.mjs: the list of TypeScript
 * files that already exceed the max-lines limit enforced in eslint.config.mjs.
 * Baselined files are exempt from the rule; the list should only shrink.
 *
 * Files that carry their own file-wide `eslint-disable max-lines` comment are
 * skipped: they are already exempt with a written justification next to the
 * code, which is the preferred escape hatch for a file that genuinely cannot
 * be split (for example a function serialized into another process).
 *
 * Usage: node tools/eslint/generate-max-lines-baseline.mjs
 */

import { readdirSync, readFileSync, writeFileSync } from 'node:fs';
import path from 'node:path';
import process from 'node:process';

export const MAX_LINES = 400;

const workspaceRoot = process.cwd();
const scanRoots = ['apps', 'libs', 'tools'];
const skipDirs = new Set(['node_modules', 'dist', '.nx', 'coverage']);

function collectTsFiles(dir, results) {
    for (const entry of readdirSync(dir, { withFileTypes: true })) {
        if (entry.isDirectory()) {
            if (!skipDirs.has(entry.name)) {
                collectTsFiles(path.join(dir, entry.name), results);
            }
        } else if (
            (entry.name.endsWith('.ts') || entry.name.endsWith('.tsx')) &&
            !entry.name.endsWith('.d.ts')
        ) {
            results.push(path.join(dir, entry.name));
        }
    }
    return results;
}

function countLines(content) {
    if (content.length === 0) {
        return 0;
    }
    const lines = content.split('\n').length;
    return content.endsWith('\n') ? lines - 1 : lines;
}

/**
 * True when the file already suppresses max-lines with a file-wide
 * `/* eslint-disable *\/` comment. Those files are deliberately exempt with a
 * reviewed justification, so baselining them too would be redundant — and
 * would wrongly imply they merely predate the rule.
 */
function hasInlineMaxLinesDisable(content) {
    // Only a file-wide `eslint-disable` block comment can suppress max-lines;
    // the rule reports at the line where the limit is exceeded, so
    // `eslint-disable-next-line` cannot apply to it.
    const disableComments = content.matchAll(
        /\/\*\s*eslint-disable\s*([^*]*?)\*\//g
    );
    for (const [, ruleList = ''] of disableComments) {
        // `/* eslint-disable */` with no rules disables everything.
        const rules = ruleList.split('--')[0].trim();
        if (rules === '') {
            return true;
        }
        if (
            rules
                .split(',')
                .some((rule) => rule.trim() === 'max-lines')
        ) {
            return true;
        }
    }
    return false;
}

const offenders = scanRoots
    .flatMap((root) => collectTsFiles(path.join(workspaceRoot, root), []))
    .map((filePath) => {
        const content = readFileSync(filePath, 'utf8');
        return {
            file: path
                .relative(workspaceRoot, filePath)
                .split(path.sep)
                .join('/'),
            lines: countLines(content),
            disabled: hasInlineMaxLinesDisable(content),
        };
    })
    .filter(({ lines, disabled }) => lines > MAX_LINES && !disabled)
    .sort((a, b) => a.file.localeCompare(b.file));

const banner = `// Generated by tools/eslint/generate-max-lines-baseline.mjs — do not edit by hand.
// TypeScript files that predate the max-lines (${MAX_LINES}) ESLint rule.
// This list should only shrink: split a file below the limit, rerun the
// generator, and commit the result. Never add new files here.
// A new file that genuinely cannot be split takes a file-wide
// \`/* eslint-disable max-lines -- <why> */\` instead; the generator skips those.
`;

const body = offenders.map(({ file }) => `    '${file}',`).join('\n');

writeFileSync(
    path.join(workspaceRoot, 'tools/eslint/max-lines-baseline.mjs'),
    `${banner}export const maxLinesBaseline = [\n${body}\n];\n`
);

console.log(`Baselined ${offenders.length} files over ${MAX_LINES} lines.`);