feat: add findWorkspaceRoot

src/_utils.ts

@@ -0,0 +1,8 @@
+import { statSync } from 'fs'
+
+export const isFile = (path: string): boolean => {
+  try {
+    if (statSync(path).isFile()) { return true }
+  } catch {}
+  return false
+}

src/index.ts

@@ -7,6 +7,7 @@ import { isAbsolute } from 'pathe'
 
 export * from './types'
 export * from './utils'
+export * from './workspace'
 
 export type ResolveOptions = _ResolveOptions & FindNearestFileOptions
 

src/utils.ts

@@ -1,5 +1,5 @@
-import { statSync } from 'fs'
 import { join, resolve } from 'pathe'
+import { isFile } from './_utils'
 
 export interface FindNearestFileOptions {
   /**
@@ -24,12 +24,7 @@ export interface FindNearestFileOptions {
 const defaultFindOptions: Required<FindNearestFileOptions> = {
   startingFrom: '.',
   rootPattern: /^node_modules$/,
-  test: (filePath: string) => {
-    try {
-      if (statSync(filePath).isFile()) { return true }
-    } catch { }
-    return null
-  }
+  test: (filePath: string) => isFile(filePath) || null
 }
 
 export async function findNearestFile (filename: string, _options: FindNearestFileOptions = {}): Promise<string> {

src/workspace.ts

@@ -0,0 +1,34 @@
+import { promises as fsp } from 'fs'
+import { ResolveOptions, resolvePath } from 'mlly'
+import { isAbsolute, join } from 'pathe'
+import { PackageJson } from './types'
+import { findNearestFile } from './utils'
+import { isFile } from './_utils'
+import { resolvePackageJSON } from '.'
+
+const rootFiles = ['pnpm-workspace.yaml', 'pnpm-lock.yaml', 'yarn.lock', 'lerna.json']
+
+export async function findWorkspaceRoot (id: string = process.cwd(), opts: ResolveOptions = {}): Promise<string> {
+  const resolvedPath = isAbsolute(id) ? id : await resolvePath(id, opts)
+  try {
+    return await findNearestFile('package.json', {
+      startingFrom: resolvedPath,
+      test: async (filePath) => {
+        if (!isFile(filePath)) {
+          return false
+        }
+        if (rootFiles.some(file => isFile(join(filePath, '..', file)))) {
+          return true
+        }
+        try {
+          const blob = await fsp.readFile(resolvedPath, 'utf-8')
+          return !!(JSON.parse(blob) as PackageJson).workspaces
+        } catch {}
+        return false
+      },
+      ...opts
+    })
+  } catch {
+    return resolvePackageJSON(id, opts)
+  }
+}

test/index.test.ts

@@ -10,6 +10,7 @@ import {
   writePackageJSON,
   writeTSConfig,
   TSConfig,
+  findWorkspaceRoot
 } from '../src'
 
 const fixtureDir = resolve(dirname(fileURLToPath(import.meta.url)), 'fixture')
@@ -61,6 +62,10 @@ describe('package.json', () => {
   it('correctly reads a version from package', async () => {
     expect(await readPackageJSON('pathe').then(p => p?.version)).to.be.a('string')
   })
+
+  it('finds the workspace root', async () => {
+    expect(await findWorkspaceRoot(rFixture('.'))).toBe(rFixture('../../package.json'))
+  })
 })
 
 describe('tsconfig.json', () => {