Raising exceptions when requesting static files if the file is not in…

… the repo (relative path goes out of repo) or when the file doesn't exist (#8)

arca/_arca.py

@@ -9,7 +9,7 @@
 from dogpile.cache import make_region, CacheRegion
 from git import Repo
 
-from .exceptions import ArcaMisconfigured
+from .exceptions import ArcaMisconfigured, FileOutOfRangeError
 from .backend import BaseBackend
 from .result import Result
 from .task import Task
@@ -87,7 +87,7 @@ def _make_region(self) -> CacheRegion:
             region.set("last_arca_run", datetime.now().isoformat())
         except ModuleNotFoundError:
             raise ModuleNotFoundError("Cache backend cannot load a required library.")
-        except Exception as e:
+        except Exception:
             raise ArcaMisconfigured("The provided cache is not working - most likely misconfigured.")
 
         return region
@@ -214,6 +214,12 @@ def static_filename(self, repo: str, branch: str, relative_path: Union[str, Path
         result = repo_path / relative_path
         result = result.resolve()
 
+        if repo_path not in result.parents:
+            raise FileOutOfRangeError(f"{relative_path} is not inside the repository.")
+
+        if not result.exists():
+            raise FileNotFoundError(f"{relative_path} does not exist in the repository.")
+
         logger.info("Static path for %s is %s", relative_path, result)
 
         return result

arca/exceptions.py

@@ -4,7 +4,7 @@ class ArcaException(Exception):
     pass
 
 
-class ArcaMisconfigured(ArcaException):
+class ArcaMisconfigured(ValueError, ArcaException):
     pass
 
 
@@ -24,3 +24,7 @@ class PushToRegistryError(ArcaException):
     def __init__(self, *args, full_output=None,  **kwargs):
         super().__init__(*args, **kwargs)
         self.full_output = full_output
+
+
+class FileOutOfRangeError(ValueError, ArcaException):
+    pass

tests/backend/test_backends.py

@@ -7,7 +7,7 @@
 from git import Repo
 
 from arca import Arca, VenvBackend, DockerBackend, Task
-from arca.exceptions import BuildError
+from arca.exceptions import BuildError, FileOutOfRangeError
 
 if os.environ.get("TRAVIS", False):
     BASE_DIR = "/home/travis/build/{}/test_loc".format(os.environ.get("TRAVIS_REPO_SLUG", "mikicz/arca"))
@@ -156,6 +156,8 @@ def test_static_files(backend, file_location):
     arca = Arca(backend=backend, base_dir=BASE_DIR)
 
     git_dir = Path("/tmp/arca/") / str(uuid4())
+    git_url = f"file://{git_dir}"
+    branch = "master"
 
     repo = Repo.init(git_dir)
     if not file_location:
@@ -169,11 +171,18 @@ def test_static_files(backend, file_location):
     repo.index.commit("Initial")
 
     relative_path = Path(file_location) / "test_file.txt"
+    nonexistent_relative_path = Path(file_location) / "test_file2.txt"
 
-    result = arca.static_filename(f"file://{git_dir}", "master", relative_path)
+    result = arca.static_filename(git_url, branch, relative_path)
 
     assert filepath.read_text() == result.read_text()
 
-    result = arca.static_filename(f"file://{git_dir}", "master", str(relative_path))
+    result = arca.static_filename(git_url, branch, str(relative_path))
 
     assert filepath.read_text() == result.read_text()
+
+    with pytest.raises(FileOutOfRangeError):
+        arca.static_filename(git_url, branch, "../file.txt")
+
+    with pytest.raises(FileNotFoundError):
+        arca.static_filename(git_url, branch, nonexistent_relative_path)