fix: detect Deno workspace root (fix #22237)

packages/vite/src/node/server/__tests__/fixtures/deno/deno.json

@@ -0,0 +1,3 @@
+{
+  "workspace": ["nested"]
+}

packages/vite/src/node/server/__tests__/fixtures/deno/nested/package.json

@@ -0,0 +1,3 @@
+{
+  "private": true
+}

packages/vite/src/node/server/__tests__/search-root.spec.ts

@@ -31,6 +31,18 @@ describe('searchForWorkspaceRoot', () => {
     expect(resolved).toBe(resolve(dirname, 'fixtures/yarn'))
   })
 
+  test('deno', () => {
+    const resolved = searchForWorkspaceRoot(
+      resolve(dirname, 'fixtures/deno/nested'),
+    )
+    expect(resolved).toBe(resolve(dirname, 'fixtures/deno'))
+  })
+
+  test('deno at root', () => {
+    const resolved = searchForWorkspaceRoot(resolve(dirname, 'fixtures/deno'))
+    expect(resolved).toBe(resolve(dirname, 'fixtures/deno'))
+  })
+
   test('none', () => {
     const resolved = searchForWorkspaceRoot(
       resolve(dirname, 'fixtures/none/nested'),

packages/vite/src/node/server/searchRoot.ts

@@ -35,6 +35,24 @@ function hasWorkspacePackageJSON(root: string): boolean {
   }
 }
 
+// https://docs.deno.com/runtime/fundamentals/workspaces/
+function hasWorkspaceDenoJSON(root: string): boolean {
+  for (const name of ['deno.json', 'deno.jsonc']) {
+    const path = join(root, name)
+    if (!isFileReadable(path)) {
+      continue
+    }
+    try {
+      const content = JSON.parse(fs.readFileSync(path, 'utf-8')) || {}
+      if (content.workspace) return true
+    } catch {
+      // deno.jsonc is only detected when it is also valid JSON. Full
+      // JSONC parsing would require an additional parser.
+    }
+  }
+  return false
+}
+
 function hasRootFile(root: string): boolean {
   return ROOT_FILES.some((file) => fs.existsSync(join(root, file)))
 }
@@ -69,6 +87,7 @@ export function searchForWorkspaceRoot(
 ): string {
   if (hasRootFile(current)) return current
   if (hasWorkspacePackageJSON(current)) return current
+  if (hasWorkspaceDenoJSON(current)) return current
 
   const dir = dirname(current)
   // reach the fs root