From 8b53c0802cdd119beebc563d5fc791248391ccb7 Mon Sep 17 00:00:00 2001
From: pooya parsa <pooya@pi0.io>
Date: Tue, 6 Sep 2022 14:30:21 +0200
Subject: [PATCH] feat: `findWorkspaceDir` (#34)

---
 README.md          | 15 +++++++++++++++
 src/index.ts       | 28 +++++++++++++++++++++++++++-
 src/utils.ts       |  2 +-
 test/index.test.ts | 12 +++++++++++-
 4 files changed, 54 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index 5b890ac..831175a 100644
--- a/README.md
+++ b/README.md
@@ -106,6 +106,21 @@ import { resolveLockFile } from 'pkg-types'
 const lockfile = await resolveLockFile('.')
 ```
 
+### `findWorkspaceDir`
+
+Try to detect workspace dir by in order:
+
+1. Nearest `.git` directory
+2. Farthest lockfile
+3. Farthest `package.json` file
+
+If fails, throws an error.
+
+```js
+import { findWorkspaceDir } from 'pkg-types'
+const workspaceDir = await findWorkspaceDir('.')
+```
+
 ## Types
 
 **Note:** In order to make types working, you need to install `typescript` as a devDependency.
diff --git a/src/index.ts b/src/index.ts
index 12e37d9..23c6832 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,7 +1,8 @@
 import { promises as fsp } from 'fs'
+import { dirname, resolve } from 'path'
 import { ResolveOptions as _ResolveOptions, resolvePath } from 'mlly'
 import { isAbsolute } from 'pathe'
-import { FindFileOptions, findNearestFile } from './utils'
+import { findFile, FindFileOptions, findNearestFile } from './utils'
 import type { PackageJson, TSConfig } from './types'
 
 export * from './types'
@@ -60,3 +61,28 @@ export async function resolveLockfile (id: string = process.cwd(), opts: Resolve
   }
   throw new Error('No lockfile found from ' + id)
 }
+
+export async function findWorkspaceDir (id: string = process.cwd(), opts: ResolveOptions = {}): Promise<string> {
+  const resolvedPath = isAbsolute(id) ? id : await resolvePath(id, opts)
+  const _opts = { startingFrom: resolvedPath, ...opts }
+
+  // Lookup for .git/config
+  try {
+    const r = await findNearestFile('.git/config', _opts)
+    return resolve(r, '../..')
+  } catch { }
+
+  // Lookdown for lockfile
+  try {
+    const r = await resolveLockfile(resolvedPath, { ..._opts, reverse: true })
+    return dirname(r)
+  } catch { }
+
+  // Lookdown for package.json
+  try {
+    const r = await findFile(resolvedPath, _opts)
+    return dirname(r)
+  } catch { }
+
+  throw new Error('Cannot detect workspace root from ' + id)
+}
diff --git a/src/utils.ts b/src/utils.ts
index 70efce2..468dd3a 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -61,7 +61,7 @@ export async function findFile (filename: string, _options: FindFileOptions = {}
       if (await options.test(filePath)) { return filePath }
     }
   } else {
-    for (let i = root + 1; i < segments.length; i++) {
+    for (let i = root + 1; i <= segments.length; i++) {
       const filePath = join(...segments.slice(0, i), filename)
       if (await options.test(filePath)) { return filePath }
     }
diff --git a/test/index.test.ts b/test/index.test.ts
index b2e2670..7771a8e 100644
--- a/test/index.test.ts
+++ b/test/index.test.ts
@@ -11,7 +11,8 @@ import {
   writeTSConfig,
   TSConfig,
   ResolveOptions,
-  resolveLockfile
+  resolveLockfile,
+  findWorkspaceDir
 } from '../src'
 
 const fixtureDir = resolve(dirname(fileURLToPath(import.meta.url)), 'fixture')
@@ -97,3 +98,12 @@ describe('resolveLockfile', () => {
     expect(await resolveLockfile(rFixture('.'))).to.equal(rFixture('../..', 'pnpm-lock.yaml'))
   })
 })
+
+describe('findWorkspaceDir', () => {
+  it('works', async () => {
+    expect(await findWorkspaceDir(rFixture('./sub'))).to.equal(rFixture('../..'))
+    expect(await findWorkspaceDir(rFixture('.'))).to.equal(rFixture('../..'))
+    expect(await findWorkspaceDir(rFixture('..'))).to.equal(rFixture('../..'))
+    expect(await findWorkspaceDir(rFixture('../..'))).to.equal(rFixture('../..'))
+  })
+})