Use bun for autoupgrade when CLI installed via bun add -g

packages/cli-kit/src/public/node/is-global.test.ts

@@ -246,6 +246,25 @@ describe('inferPackageManagerForGlobalCLI', () => {
     expect(got).toBe('homebrew')
   })
 
+  test('returns bun when symlink under ~/.bun/bin resolves out of the bun install dir', async () => {
+    // Given: `bun add -g @shopify/cli` creates ~/.bun/bin/shopify as a symlink to
+    // ../../node_modules/@shopify/cli/bin/run.js, which on most setups resolves to
+    // <home>/node_modules/@shopify/cli/bin/run.js — a path that does NOT contain "bun".
+    // Without inspecting the original symlink path we'd fall through to npm and the
+    // autoupgrade flow would shell out to `npm install -g` instead of `bun add -g`.
+    const symlinkPath = '/users/fonso/.bun/bin/shopify'
+    const realBunPath = '/users/fonso/node_modules/@shopify/cli/bin/run.js'
+    const argv = ['node', symlinkPath, 'shopify']
+
+    vi.mocked(realpathSync).mockImplementationOnce(() => realBunPath)
+
+    // When
+    const got = inferPackageManagerForGlobalCLI(argv)
+
+    // Then
+    expect(got).toBe('bun')
+  })
+
   test('defaults to npm if realpath fails and no other indicator is present', async () => {
     // Given: A path that realpathSync cannot resolve
     const nonExistentPath = '/opt/homebrew/bin/shopify'

packages/cli-kit/src/public/node/is-global.ts

@@ -105,19 +105,27 @@ export function inferPackageManagerForGlobalCLI(argv = process.argv, env = proce
   }
 
   const processArgv = argv[1] ?? ''
+  const symlinkPath = processArgv.toLowerCase()
 
   // Resolve symlinks to get the real path of the binary.
-  let realPath = processArgv.toLowerCase()
+  let realPath = symlinkPath
   try {
     realPath = realpathSync(processArgv).toLowerCase()
     // eslint-disable-next-line no-catch-all/no-catch-all
   } catch (error) {
     // fall back to using the original path for detection
   }
 
-  if (realPath.includes('yarn')) return 'yarn'
-  if (realPath.includes('pnpm')) return 'pnpm'
-  if (realPath.includes('bun')) return 'bun'
+  // Inspect both the (unresolved) symlink path and the resolved real path. Some
+  // package managers — notably bun (`~/.bun/bin/<name>`) — install global binaries
+  // as symlinks pointing into a generic `node_modules` directory whose real path
+  // no longer contains the package manager name. The original symlink under the
+  // PM's bin dir is the most reliable signal in that case.
+  const matches = (needle: string) => realPath.includes(needle) || symlinkPath.includes(needle)
+
+  if (matches('yarn')) return 'yarn'
+  if (matches('pnpm')) return 'pnpm'
+  if (matches('bun')) return 'bun'
 
   // Check for Homebrew via Cellar path (resolved symlink)
   if (realPath.includes('/cellar/')) return 'homebrew'