feat: link module to itself during stub

this way we can reference package by name in tests (similar to what lerna does)

src/build.ts

@@ -8,6 +8,7 @@ import rimraf from 'rimraf'
 import defu from 'defu'
 import prettyBytes from 'pretty-bytes'
 import jiti from 'jiti'
+import { dumpObject, symlink } from './utils'
 import type { BuildContext } from './types'
 import { validateDependencies } from './validate'
 import { rollupBuild } from './builder/rollup'
@@ -79,6 +80,11 @@ export async function build (rootDir: string, stub: boolean) {
     await mkdir(outDir).catch(() => { })
   }
 
+  // selflink
+  if (ctx.stub) {
+    await symlink(resolve(ctx.rootDir), resolve(ctx.rootDir, 'node_modules', ctx.pkg.name))
+  }
+
   // untyped
   await typesBuild(ctx)
 
@@ -88,6 +94,11 @@ export async function build (rootDir: string, stub: boolean) {
   // rollup
   await rollupBuild(ctx)
 
+  // Skip rest for stub
+  if (ctx.stub) {
+    return
+  }
+
   // Done info
   consola.success(chalk.green('Build succeed for ' + pkg.name))
   for (const entry of ctx.buildEntries) {
@@ -104,6 +115,3 @@ export async function build (rootDir: string, stub: boolean) {
   consola.log('')
 }
 
-function dumpObject (obj: Record<string, any>) {
-  return '{ ' + Object.keys(obj).map(key => `${key}: ${JSON.stringify(obj[key])}`).join(', ') + ' }'
-}

src/builder/mkdist.ts

@@ -1,14 +1,13 @@
-import { unlink, symlink } from 'fs/promises'
 import { mkdist } from 'mkdist'
 import { resolve, join } from 'upath'
+import { symlink } from '../utils'
 import type { BuildContext } from '../types'
 
 export async function mkdistBuild (ctx: BuildContext) {
   for (const entry of ctx.entries.filter(e => e.builder === 'mkdist')) {
     if (ctx.stub) {
       const srcDir = resolve(ctx.rootDir, entry.input)
       const outDir = resolve(ctx.rootDir, ctx.outDir, entry.name)
-      await unlink(outDir).catch(() => { })
       await symlink(srcDir, outDir)
     } else {
       const { writtenFiles } = await mkdist({

src/utils.ts

@@ -0,0 +1,12 @@
+import fsp from 'fs/promises'
+
+export async function symlink (from: string, to: string, force: boolean = true) {
+  if (force) {
+    await fsp.unlink(to).catch(() => { })
+  }
+  await fsp.symlink(from, to)
+}
+
+export function dumpObject (obj: Record<string, any>) {
+  return '{ ' + Object.keys(obj).map(key => `${key}: ${JSON.stringify(obj[key])}`).join(', ') + ' }'
+}