prompt: We are currently solving the following issue within our repository. Here is the issue text:
  --- BEGIN ISSUE ---
  `DigestEntries` returns a `Directory` instead of an empty vector for non-matching digest
  
  
  --- END ISSUE ---
  
  Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
  --- BEGIN FILES ---
  Path: `src/python/pants/jvm/util_rules.py`
  Content:
  ```
  1 # Copyright 2021 Pants project contributors (see CONTRIBUTORS.md).
  2 # Licensed under the Apache License, Version 2.0 (see LICENSE).
  3 
  4 from __future__ import annotations
  5 
  6 from dataclasses import dataclass
  7 
  8 from pants.engine.fs import Digest, DigestEntries, DigestSubset, FileDigest, FileEntry, PathGlobs
  9 from pants.engine.rules import Get, collect_rules, rule
  10 
  11 
  12 @dataclass(frozen=True)
  13 class ExtractFileDigest:
  14     digest: Digest
  15     file_path: str
  16 
  17 
  18 @rule
  19 async def digest_to_file_digest(request: ExtractFileDigest) -> FileDigest:
  20     digest = await Get(Digest, DigestSubset(request.digest, PathGlobs([request.file_path])))
  21     files_or_directories = await Get(DigestEntries, Digest, digest)
  22     digest_entries = [entry for entry in files_or_directories if isinstance(entry, FileEntry)]
  23 
  24     if len(digest_entries) == 0:
  25         raise Exception(f"ExtractFileDigest: '{request.file_path}' not found in {request.digest}.")
  26     elif len(digest_entries) > 1:
  27         raise Exception(
  28             f"ExtractFileDigest: Unexpected error: '{request.file_path}' found multiple times in {request.digest}"
  29         )
  30 
  31     file_info = digest_entries[0]
  32     return file_info.file_digest
  33 
  34 
  35 def rules():
  36     return [*collect_rules()]
  37
  ```
  --- END FILES ---
  
  Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.
  
  Here is an example:
  
  ```diff
  diff --git a/examples/server_async.py b/examples/server_async.py
  --- a/examples/server_async.py
  +++ b/examples/server_async.py
  @@ -313,4 +313,4 @@
   
   
   if __name__ == "__main__":
  -    asyncio.run(run_async_server("."), debug=True)
  +    asyncio.run(run_async_server(), debug=True)
  diff --git a/examples/server_sync.py b/examples/server_sync.py
  --- a/examples/server_sync.py
  +++ b/examples/server_sync.py
  @@ -313,5 +313,5 @@
   
   
   if __name__ == "__main__":
  -    server = run_sync_server(".")
  +    server = run_sync_server()
       server.shutdown()
  
  ```
  
golden_diff: diff --git a/src/python/pants/jvm/util_rules.py b/src/python/pants/jvm/util_rules.py
  --- a/src/python/pants/jvm/util_rules.py
  +++ b/src/python/pants/jvm/util_rules.py
  @@ -18,8 +18,7 @@
   @rule
   async def digest_to_file_digest(request: ExtractFileDigest) -> FileDigest:
       digest = await Get(Digest, DigestSubset(request.digest, PathGlobs([request.file_path])))
  -    files_or_directories = await Get(DigestEntries, Digest, digest)
  -    digest_entries = [entry for entry in files_or_directories if isinstance(entry, FileEntry)]
  +    digest_entries = await Get(DigestEntries, Digest, digest)
   
       if len(digest_entries) == 0:
           raise Exception(f"ExtractFileDigest: '{request.file_path}' not found in {request.digest}.")
  @@ -29,6 +28,12 @@
           )
   
       file_info = digest_entries[0]
  +
  +    if not isinstance(file_info, FileEntry):
  +        raise AssertionError(
  +            f"Unexpected error: '{request.file_path}' refers to a directory, not a file."
  +        )
  +
       return file_info.file_digest
  
verification_info: {"golden_diff": "diff --git a/src/python/pants/jvm/util_rules.py b/src/python/pants/jvm/util_rules.py\n--- a/src/python/pants/jvm/util_rules.py\n+++ b/src/python/pants/jvm/util_rules.py\n@@ -18,8 +18,7 @@\n @rule\n async def digest_to_file_digest(request: ExtractFileDigest) -> FileDigest:\n     digest = await Get(Digest, DigestSubset(request.digest, PathGlobs([request.file_path])))\n-    files_or_directories = await Get(DigestEntries, Digest, digest)\n-    digest_entries = [entry for entry in files_or_directories if isinstance(entry, FileEntry)]\n+    digest_entries = await Get(DigestEntries, Digest, digest)\n \n     if len(digest_entries) == 0:\n         raise Exception(f\"ExtractFileDigest: '{request.file_path}' not found in {request.digest}.\")\n@@ -29,6 +28,12 @@\n         )\n \n     file_info = digest_entries[0]\n+\n+    if not isinstance(file_info, FileEntry):\n+        raise AssertionError(\n+            f\"Unexpected error: '{request.file_path}' refers to a directory, not a file.\"\n+        )\n+\n     return file_info.file_digest\n", "issue": "`DigestEntries` returns a `Directory` instead of an empty vector for non-matching digest\n\n", "before_files": [{"content": "# Copyright 2021 Pants project contributors (see CONTRIBUTORS.md).\n# Licensed under the Apache License, Version 2.0 (see LICENSE).\n\nfrom __future__ import annotations\n\nfrom dataclasses import dataclass\n\nfrom pants.engine.fs import Digest, DigestEntries, DigestSubset, FileDigest, FileEntry, PathGlobs\nfrom pants.engine.rules import Get, collect_rules, rule\n\n\n@dataclass(frozen=True)\nclass ExtractFileDigest:\n    digest: Digest\n    file_path: str\n\n\n@rule\nasync def digest_to_file_digest(request: ExtractFileDigest) -> FileDigest:\n    digest = await Get(Digest, DigestSubset(request.digest, PathGlobs([request.file_path])))\n    files_or_directories = await Get(DigestEntries, Digest, digest)\n    digest_entries = [entry for entry in files_or_directories if isinstance(entry, FileEntry)]\n\n    if len(digest_entries) == 0:\n        raise Exception(f\"ExtractFileDigest: '{request.file_path}' not found in {request.digest}.\")\n    elif len(digest_entries) > 1:\n        raise Exception(\n            f\"ExtractFileDigest: Unexpected error: '{request.file_path}' found multiple times in {request.digest}\"\n        )\n\n    file_info = digest_entries[0]\n    return file_info.file_digest\n\n\ndef rules():\n    return [*collect_rules()]\n", "path": "src/python/pants/jvm/util_rules.py"}], "after_files": [{"content": "# Copyright 2021 Pants project contributors (see CONTRIBUTORS.md).\n# Licensed under the Apache License, Version 2.0 (see LICENSE).\n\nfrom __future__ import annotations\n\nfrom dataclasses import dataclass\n\nfrom pants.engine.fs import Digest, DigestEntries, DigestSubset, FileDigest, FileEntry, PathGlobs\nfrom pants.engine.rules import Get, collect_rules, rule\n\n\n@dataclass(frozen=True)\nclass ExtractFileDigest:\n    digest: Digest\n    file_path: str\n\n\n@rule\nasync def digest_to_file_digest(request: ExtractFileDigest) -> FileDigest:\n    digest = await Get(Digest, DigestSubset(request.digest, PathGlobs([request.file_path])))\n    digest_entries = await Get(DigestEntries, Digest, digest)\n\n    if len(digest_entries) == 0:\n        raise Exception(f\"ExtractFileDigest: '{request.file_path}' not found in {request.digest}.\")\n    elif len(digest_entries) > 1:\n        raise Exception(\n            f\"ExtractFileDigest: Unexpected error: '{request.file_path}' found multiple times in {request.digest}\"\n        )\n\n    file_info = digest_entries[0]\n\n    if not isinstance(file_info, FileEntry):\n        raise AssertionError(\n            f\"Unexpected error: '{request.file_path}' refers to a directory, not a file.\"\n        )\n\n    return file_info.file_digest\n\n\ndef rules():\n    return [*collect_rules()]\n", "path": "src/python/pants/jvm/util_rules.py"}]}