michael-andreuzza/astromax/get-tsconfig

type TsconfigResult<Config = TsconfigJsonResolved> = {
    path: string
    config: Config
}
// TsconfigJson = raw tsconfig shape (includes extends field)
// TsconfigJsonResolved = TsconfigJson without extends (fully merged)
type GetTsconfigOptions = {
    configName?: string   // default: 'tsconfig.json' (use 'jsconfig.json' for JS projects)
    cache?: Map<string, unknown>
    includes?: boolean    // default: false — when true, validates file is a root file before accepting
}
type ReadTsconfigOptions = {
    cache?: Map<string, unknown>
}

import { getTsconfig, isFileIncluded, resolvePathAlias } from 'get-tsconfig'
const tsconfig = getTsconfig()
// Check if a file should be transformed with this tsconfig's options
if (tsconfig && isFileIncluded(tsconfig, absoluteFilePath)) {
    const { compilerOptions } = tsconfig.config
    // Pass to esbuild, SWC, etc. as tsconfigRaw
}
// Resolve path aliases (returns candidate paths — check which exist)
const resolved = tsconfig && resolvePathAlias(tsconfig, '@/utils/helper')
// → ['/project/src/utils/helper'] or []

const cache = new Map()
const getConfigForFile = (filePath: string) =>
    getTsconfig(filePath, { cache })

const { compilerOptions } = getTsconfig().config
compilerOptions.noImplicitAny    // true (implied by strict: true)
compilerOptions.strictNullChecks // true (implied by strict: true)
compilerOptions.esModuleInterop  // true (implied by module: 'nodenext')
compilerOptions.allowJs          // true (implied by checkJs: true)

import { getExtendsChain } from 'get-tsconfig'
const chain = getExtendsChain('./tsconfig.json')
const filesToWatch = chain.map(entry => entry.path)

import { getExtendsChain, resolveExtendsChain } from 'get-tsconfig'
const chain = getExtendsChain('./tsconfig.json')
chain[0].config.compilerOptions = {
    ...chain[0].config.compilerOptions,
    sourceMap: true,
}
const result = resolveExtendsChain(chain)

// Default: nearest tsconfig (tsc CLI behavior)
getTsconfig('./src/index.ts')
// Validates file is a root file before accepting (VS Code behavior)
getTsconfig('./src/index.ts', { includes: true })