Lint in VS Code

This page is for @ttsc/lint users who want compiler, lint, and contributor-plugin assistance in one VS Code session.

The @ttsc/vscode extension starts one ttscserver for the selected project. That server forwards TypeScript-Go language features and merges the editor features published by @ttsc/lint and its contributor rules into the same LSP stream.

The editor does not start a separate ESLint language server or maintain a second rule config. It resolves the project’s own ttsc, typescript, tsconfig.json, plugins, and lint.config.*.

Install the editor path

Install the project dependencies, then install the extension:

npm install -D ttsc typescript @ttsc/lint
npx @ttsc/vscode

The extension also ships through the VS Code Marketplace as samchon.ttsc. See Setup → VS Code for the direct code --install-extension form, formatter settings, multi-root behavior, and server tracing.

Complete a valid JSDoc tag

Enable the built-in jsdoc/check-tag-names rule in the global rules map:

// lint.config.ts
import type { ITtscLintConfig } from "@ttsc/lint";
 
export default {
  rules: {
    "jsdoc/check-tag-names": "error",
    "no-var": "error",
  },
  format: {
    singleQuote: true,
    trailingComma: "all",
  },
} satisfies ITtscLintConfig;

Open a TypeScript file and start a JSDoc tag:

/**
 * Greets one user.
 * @par
 */
export function greet(name: string): string {
  return `Hello, ${name}`;
}

With the cursor after @par, VS Code offers param from the same tag set that jsdoc/check-tag-names validates. Select it, then finish the line as @param name user name. You can also press Ctrl+Space to request completion explicitly.

Use the completion inside a TypeScript /** ... */ JSDoc block. Decorators, line comments, Markdown documents, and text inside string, template, or regular expression literals are outside the supported scope. A literal that contains the characters /**, such as const example = "/** @par", is literal text and stays outside it too.

Completion uses the live editor buffer, so it remains available while the file is dirty. The rule’s completion corpus is discovered in the background when the language server starts, and rediscovered after you save a file, after a ttsc setting changes, and after a watched tsconfig.json changes. Enabling a rule or changing a contributor’s indexed inputs therefore reaches the editor on the next save, without a restart. Discovery runs in the background, so the new items appear a moment after the save rather than during it.

One case still needs ttsc: Restart language server: a rule that publishes completion after a character the session never advertised. The server merges each corpus trigger character into TypeScript-Go’s list while answering initialize, and a corpus discovered later cannot change a response the editor already has. The items themselves still work — press Ctrl+Space, or type a character the session already advertised, such as @ inside a JSDoc block. When this happens the server writes a note naming the character to View → Output → ttsc.

See the same rule reject a typo

Leave an unknown tag such as @parm in the JSDoc block and save the file. jsdoc/check-tag-names publishes its finding beside TypeScript-Go diagnostics through the same Problems panel and source underline.

Plugin diagnostics and code actions use the saved project state. Save before relying on a new lint diagnostic or invoking a lint action. TypeScript-Go language features and project-rule completion continue to use the live buffer, while format-on-save formats that live buffer as part of the save.

“Saved project state” means the project as it is on disk right now, not as it was when the language server started. A file that changed on disk while it was closed is re-read when you open it, and a tsconfig.json or jsconfig.json edit is picked up from the editor’s file watcher, so a branch switch, a git pull, a generator run, or a config change takes effect without restarting the language server.

Suggestions, fixes, and format

Rules can offer suggestions for repairs that require a choice. Put the cursor on the diagnostic and open Quick Fix to select one. Suggestions are editor-only actions and never run automatically during ttsc fix.

Automatic fixes are available through ttsc: Fix all lint issues or the source.fixAll.ttsc code action. To run fix-all explicitly on save:

{
  "editor.codeActionsOnSave": {
    "source.fixAll.ttsc": "explicit"
  }
}

Formatting is a separate write operation. Set samchon.ttsc as the default formatter to use the same format block from lint.config.* in VS Code and ttsc format:

{
  "[typescript][typescriptreact]": {
    "editor.defaultFormatter": "samchon.ttsc",
    "editor.formatOnSave": true
  }
}

See Format for every supported key and the fallback to VS Code indentation and line-ending settings when no format block exists.

Contributor project indexes

jsdoc/check-tag-names publishes a fixed set of known tags. A contributor project rule can publish completions from the state it indexed for the loaded Program. ttscserver appends those items to TypeScript-Go’s completion response instead of replacing it.

The feature originated from work on @samchon/evidence. Its feat/editor-hints development branch shows a richer external use: a project index describing JSDoc citation tags, document paths, and section anchors. That package has its own release schedule and is not part of the ttsc distribution.

Plugin authors can implement this channel through rule.HintRule. Editor embedders can implement the driver-level CompletionHintSource.

Troubleshooting completion

1. Confirm the workspace has a tsconfig.json and resolves ttsc: npx ttsc --version.
2. Confirm jsdoc/check-tag-names is enabled in the global rules map.
3. Put the cursor inside a /** ... */ block in a TypeScript file, then press Ctrl+Space after @.
4. Save the file after changing the rule config or a contributor’s indexed project inputs; the corpus is rediscovered in the background on save. Restart the language server only for a completion trigger character the session never advertised, which the ttsc output channel names when it happens.
5. Open View → Output → ttsc for the server log. Set ttsc.trace.server to "verbose" when the normal log is not enough.

For general extension startup and project-selection failures, continue with the VS Code troubleshooting checklist.