Config & DSL Lint + Snippets — 9 Sets

Your compiler reads your code. It does not read your config.

eslint.config.js, pyproject.toml, a DeviceTree overlay, a MicroProfile .properties, an AutoHotkey v2 script, settings.json — none of these are type-checked, none are compiled, and most of them fail by doing nothing at all. The build stays green. The line is simply ignored, and you find out in staging, or you never find out.

Here is the one that is biting people right now.

ESLint v10.0.0 shipped in February 2026 and removed the eslintrc config system outright. .eslintrc.* and .eslintignore are no longer honoured. ESLint v9 reached end of life on 2026-08-06. So the day your CI bumps the major, this file:

{
  "extends": ["eslint:recommended"],
  "env": { "node": true },
  "parserOptions": { "ecmaVersion": 2024 }
}

stops being read. ESLint does not error. It lints with no configuration and reports zero problems, and a green check mark appears on the pull request that deleted every rule you had. The fix is one file, and it does not look like the old one:

import js from "@eslint/js";

export default [
  js.configs.recommended,
  {
    files: ["**/*.js"],
    languageOptions: { ecmaVersion: 2024, sourceType: "module" },
    rules: { "no-unused-vars": "warn" },
  },
];

env becomes languageOptions.globals. parserOptions moves under languageOptions. extends has no equivalent — you spread the shared config into the exported array. At the top level, the old keys are not errors. They are ignored.

The same shape repeats everywhere config is not compiled.

The Python extension removed python.pythonPath and the whole python.linting.* namespace. Your settings.json still contains them, VS Code still accepts the JSON, and your interpreter is simply not the one you think it is. "editor.defaultFormatter": "ms-python.python" no longer formats anything, because that extension stopped being a formatter.

A MicroProfile REST Client base URL with a trailing slash:

org.acme.client.CountryService/mp-rest/url=http://localhost:8080/

The container starts fine. The @Path is appended after the slash, the request goes to a double slash, and you get a 404 from a service you can see running.

A DeviceTree overlay missing one semicolon after /dts-v1/ — dtc stops at line one. status = "enabled" instead of status = "okay" — not a recognised value, so the node stays disabled and the peripheral is just absent. A gpios specifier with one cell where the controller declares #gpio-cells = <2>.

AutoHotkey v2 removed comma command syntax and #NoEnv, #Persistent, #EscapeChar, #CommentFlag. MsgBox, "text" is a v1 script that no longer runs. Ren'Py block headers need their colon. TOML has no None and its booleans are lowercase; a leading zero is not a legal integer. Swift's try! and implicitly unwrapped optionals stop the process at the exact line they fail on.

None of these produce a compiler error, because there is no compiler.

What I built

A VS Code extension that runs 28 rules across those 9 file kinds, in the editor, offline, with no toolchain to install. Open a file, run Audit this file, and every match comes back with a line number and the line to write instead. It also ships 36 snippets for the same 9 — the correct shape of a flat config, an MP fault-tolerance block, a DeviceTree i2c child node, an AHK v2 GUI — so you write the right thing the first time.

The audit is free and it is the whole audit: all 28 rules, every file you open, no key, no file limit. There is a browser version that runs the same rules on pasted text, so you can check the rule set before you install anything.

The licence buys a different job, not a bigger number: run the same check across the entire repository in one pass, keep re-checking on every save, and export the findings as CSV, JSON or HTML to hand to whoever owns the config.

A freelance senior software engineer averaged $101 an hour in 2026 across 584 verified rate submissions. Finding one silently ignored .eslintrc by hand costs more than the licence does.

Config is the last place in the stack where being wrong is silent. It does not have to stay that way.