@ttsc/lint

Lint as compile errors. Format as a write operation. One plugin, one config file, one command pipeline.

$ npx ttsc --noEmit
src/index.ts:1:1 - error TS11966: [no-var] Unexpected var, use let or const instead.

1 var x = 3;
  ~~~~~~~~~

A lint rule. Reported as error TS11966. The same error TSxxxxx shape your editor already underlines, your CI already gates on, and your IDE already takes you to with one click. No second tool, no second config, no second CI step.

The shape of the chapter

This is a big section. Here’s the order:

1. Setup — install, register the plugin, write lint.config.ts. Five minutes.
2. Rules — the rule catalog by category. What each rule does, when to keep it "error", when to keep it "warning".
3. Format rules — the format/* subset. Quotes, semis, trailing commas, the Wadler-style print-width reflow — the Prettier surface.
4. ttsc fix & ttsc format — the autofix workflow. What writes back, what doesn’t, what to commit.

If you only have five minutes: read Setup, copy the lint.config.ts starter from there, run ttsc fix once, and let the diagnostics tell you the rest.

What you get

• 140 rules, grouped by category. Most have ESLint-equivalent names. Severity per rule (error / warning / off).
• A format subset (format/*) that covers Prettier’s territory — semis, quotes, trailing commas, a print-width reflow. Replaces Prettier.
• ttsc fix — applies every available autofix (lint and format) in one pass, writes results to disk, re-checks. CI then gates on the unmodified ttsc --noEmit.
• ttsc format — the format-only version of fix, for projects that want reshape without lint rewrites.
• ESLint interop — if eslint.config.* and an ESLint runtime are present, ttsc fix delegates to ESLint’s own fixers for rules the native engine doesn’t implement, then reloads. Useful during phased migrations.

What you don’t get (yet)

• All ESLint plugins. The native rule set covers the common JS/TS rules — no-var, eqeqeq, no-explicit-any, prefer-const, and 130-some more. It does not cover eslint-plugin-react-hooks, eslint-plugin-import, eslint-plugin-jsx-a11y, or other plugin-shipped rule packages. For those, keep ESLint installed alongside; ttsc will delegate.
• Custom rule authoring inside @ttsc/lint is plugin-author territory. See Plugin Development · Reference plugin tour for how @ttsc/lint is itself written.

Next

→ Setup