JavaScript and TypeScript

gspot checks JavaScript and TypeScript with ESLint, the TypeScript compiler, and Knip, which finds code that nothing uses. These checks run for the javascript and typescript configurations:

Check	Stage	What it does
javascript/eslint	commit	Runs the shipped ESLint rules on JavaScript, TypeScript, component files, and package.json.
javascript/tsc	push	Type-checks plain JavaScript through its JSDoc comments.
javascript/knip	push	Finds files, exports, and dependencies nothing uses.
typescript/tsc	push	Runs tsc with the strict compiler options over every TypeScript file.
typescript/tsconfig	commit	Requires strict in every tsconfig you write. Level all also requires noUncheckedIndexedAccess, exactOptionalPropertyTypes, noImplicitOverride, noFallthroughCasesInSwitch, noImplicitReturns, and noPropertyAccessFromIndexSignature.

Framework configurations, such as react, nextjs, and react-native, add their own lint rules. A React project that depends on react-dom also gets the react-dom configuration and its DOM accessibility lint rules. The configuration reference lists every framework.

JavaScript runtimes

Each file gets one ESLint runtime:

Files	Runtime
Ordinary modules and build scripts	Node.js built-ins
.cjs and .cts files	Node.js built-ins and CommonJS globals
React, Vue, and Svelte application sources	Browser globals
React Native sources	Native globals
Next.js sources	Node.js built-ins, since server components can use them

To give some files another runtime, add a [[tools.eslint.override]] record. Write paths relative to the repository root. When records overlap, the later one counts.

gspot.toml

[[tools.eslint.override]]
paths = ["src/client/**"]
runtime = "browser"

[[tools.eslint.override]]
paths = ["src/workers/**"]
runtime = "worker"

[[tools.eslint.override]]
paths = ["src/serviceworker.js"]
runtime = "serviceworker"

Use an explicit node runtime for server code inside a browser or React Native project. Runtime names follow the pinned globals package. Use serviceworker for service workers, which have other APIs than Web Workers. An unknown runtime name stops gspot before it writes tool files.

Browser and native files get no Node.js lint rules. React Native files keep the process and require globals, but get no other Node.js globals, such as Buffer and __dirname.

TypeScript compiler

TypeScript source files or your own tsconfig.json select the TypeScript checks. A TypeScript tool dependency or declaration files alone do not.

The checks use the TypeScript compiler of your project. Without one, gspot uses its pinned compiler from the tool project before any global compiler. gspot install installs the pinned compiler.

Your own tsconfig.json keeps its compiler options and gets the strict ones that the selected level requires. When a scope has no tsconfig.json of your own, gspot writes a standalone compiler project for its source files and declarations. That project leaves out generator output, vendored files, and child scopes.

JavaScript checks extend your own jsconfig.json, or your tsconfig.json when no jsconfig.json exists. From a tsconfig.json, they keep the compiler options and declarations but select only JavaScript sources.

Your own JSX setting stays; without one, the generated project uses jsx: "preserve". A scope with neither file uses Bundler resolution when imports without extensions name JavaScript source files. Ambient types come from the source project, including your own type roots.

Next.js

The Next.js configuration runs nextjs/tsc instead of typescript/tsc, at level recommended and stage push. The check has Next.js write its types, then type-checks the app with the strict compiler options. The project must provide Next.js 15.5 or later. The Next.js Semgrep rules run in security/semgrep.

React Native

gspot init selects react-native and expo from their dependencies. The Expo configuration requires React Native and adds Expo lint rules and expo/expo-doctor. A bare React Native project needs no Expo tool. Native sources keep the React hooks and component lint rules.

If a component wraps the React Native Text, add its name to the skip option of the lint rule:

gspot set tools.eslint.rules '{ "react-native/no-raw-text" = [{ skip = ["ThemedText"] }] }'

This allows text inside ThemedText. The lint rule still reports bare text inside a View. When other projects use other components, set the option in the scope of the native project.

Settings that change lint rule options

Setting	What it sets
structure.environment_readers	The files that may read environment variables, for n/no-process-env, no-restricted-properties, and no-restricted-syntax
tools.eslint.import_extension	The import extension option of n/file-extension-in-import
limits.index_exports	amountOfExportsToConsiderModuleAsBarrel of barrel-files/avoid-barrel-files
structure.reexports = "index-only"	Lets index files re-export; ESLint re-export rules and gspot/no-trivial-files skip them

The environment reader checks run at level all. The limits on index files that re-export other files run at level all too, and only when you allow re-exports. The ESLint plugin page lists the options of its lint rules.