fix(cli): respect rsc: false and avoid adding 'use client' directive

packages/shadcn/src/utils/transformers/transform-rsc.ts

@@ -1,17 +1,18 @@
 import { Transformer } from "@/src/utils/transformers"
 import { SyntaxKind } from "ts-morph"
 
-const directiveRegex = /^["']use client["']$/g
-
 export const transformRsc: Transformer = async ({ sourceFile, config }) => {
   if (config.rsc) {
     return sourceFile
   }
 
   // Remove "use client" from the top of the file.
   const first = sourceFile.getFirstChildByKind(SyntaxKind.ExpressionStatement)
-  if (first && directiveRegex.test(first.getText())) {
-    first.remove()
+  if (first) {
+    const text = first.getText().trim()
+    if (text === '"use client"' || text === "'use client'") {
+      first.remove()
+    }
   }
 
   return sourceFile

packages/shadcn/test/utils/transform-rsc.test.ts

@@ -111,3 +111,73 @@ import { Foo } from 'bar'
     })
   ).toMatchSnapshot()
 })
+
+test("transform rsc - sequential calls (regression test for #8991)", async () => {
+  // Regression test to verify that the stateful regex bug in transformRsc is fixed.
+  // This test specifically checks that the "use client" directive is removed
+  // consistently across multiple sequential transformations.
+  //
+  // The original bug: Using /^["']use client["']$/g with .test() created a
+  // stateful regex that alternated between true/false on successive calls,
+  // causing the directive to be inconsistently removed when rsc: false.
+
+  const rscFalseConfig = {
+    tsx: true,
+    rsc: false,
+  }
+
+  const inputWithDoubleQuotes = `"use client"
+
+import * as React from "react"
+import { Foo } from "bar"`
+
+  // Test 1: First transformation
+  const result1 = await transform({
+    filename: "test1.ts",
+    raw: inputWithDoubleQuotes,
+    config: rscFalseConfig,
+  })
+  expect(result1).not.toContain('"use client"')
+  expect(result1).toContain('import * as React from "react"')
+
+  // Test 2: Second transformation
+  // Before the fix, this would FAIL because the regex state would alternate
+  const result2 = await transform({
+    filename: "test2.ts",
+    raw: inputWithDoubleQuotes,
+    config: rscFalseConfig,
+  })
+  expect(result2).not.toContain('"use client"')
+  expect(result2).toContain('import * as React from "react"')
+
+  // Test 3: Third transformation for additional confidence
+  const result3 = await transform({
+    filename: "test3.ts",
+    raw: inputWithDoubleQuotes,
+    config: rscFalseConfig,
+  })
+  expect(result3).not.toContain('"use client"')
+  expect(result3).toContain('import * as React from "react"')
+
+  // Test 4: Single quotes variant
+  const inputWithSingleQuotes = `'use client'
+
+import * as React from "react"
+import { Foo } from "bar"`
+
+  const result4 = await transform({
+    filename: "test4.ts",
+    raw: inputWithSingleQuotes,
+    config: rscFalseConfig,
+  })
+  expect(result4).not.toContain("'use client'")
+  expect(result4).toContain('import * as React from "react"')
+
+  // Test 5: Mixed quotes - another sequential call
+  const result5 = await transform({
+    filename: "test5.ts",
+    raw: inputWithDoubleQuotes,
+    config: rscFalseConfig,
+  })
+  expect(result5).not.toContain('"use client"')
+})