🎨 better snkconfig error handeling

snk/cli/config/config.py

@@ -2,7 +2,7 @@
 from typing import List
 import snakemake
 from dataclasses import dataclass, field
-
+from snk.errors import InvalidSnkConfigError, MissingSnkConfigError
 import yaml
 
 
@@ -35,20 +35,23 @@ def from_path(cls, snk_config_path: Path):
           >>> SnkConfig.from_path(Path("snk.yaml"))
           SnkConfig(art=None, logo=None, tagline='A Snakemake pipeline CLI generated with Snk', font='small', resources=[], annotations={}, symlink_resources=False, _snk_config_path=PosixPath('snk.yaml'))
         """
-        if snk_config_path.exists():
-            snk_config_dict = snakemake.load_configfile(snk_config_path)
-            snk_config = cls(**snk_config_dict)
-            snk_config.resources = [
-                snk_config_path.parent / resource for resource in snk_config.resources
-            ]
-            snk_config.validate_resources(snk_config.resources)
-            snk_config._snk_config_path = snk_config_path
-            return snk_config
-        else:
-            raise FileNotFoundError(
+        if not snk_config_path.exists():
+            raise MissingSnkConfigError(
                 f"Could not find SNK config file: {snk_config_path}"
-            )
+            ) from FileNotFoundError
+        # raise error if file is empty
+        if snk_config_path.stat().st_size == 0:
+            raise InvalidSnkConfigError(f"SNK config file is empty: {snk_config_path}") from ValueError
 
+        snk_config_dict = snakemake.load_configfile(snk_config_path)
+        snk_config = cls(**snk_config_dict)
+        snk_config.resources = [
+            snk_config_path.parent / resource for resource in snk_config.resources
+        ]
+        snk_config.validate_resources(snk_config.resources)
+        snk_config._snk_config_path = snk_config_path
+        return snk_config
+
     @classmethod
     def from_pipeline_dir(
         cls, pipeline_dir_path: Path, create_if_not_exists: bool = False

snk/errors.py

@@ -12,3 +12,13 @@ class PipelineNotFoundError(NestError):
 
 class InvalidPipelineRepositoryError(NestError):
     """Thrown if the given repository appears to have an invalid format."""
+
+
+class SnkConfigError(Exception):
+    """Base class for all SNK config exceptions"""
+
+class InvalidSnkConfigError(SnkConfigError, ValueError):
+    """Thrown if the given SNK config appears to have an invalid format."""
+
+class MissingSnkConfigError(SnkConfigError, FileNotFoundError):
+    """Thrown if the given SNK config file cannot be found."""

tests/snk/test_snk_config.py

@@ -44,6 +44,23 @@ def test_from_path_with_existing_file(tmp_path):
     snk_config = SnkConfig.from_path(config_file)
     assert snk_config._snk_config_path == config_file
 
+def test_missing_file(tmp_path):
+    config_file = tmp_path / "snk.yaml"
+    with pytest.raises(FileNotFoundError):
+        SnkConfig.from_path(config_file)
+
+def test_empty_file(tmp_path):
+    config_file = tmp_path / "snk.yaml"
+    config_file.touch()
+    with pytest.raises(ValueError):
+        SnkConfig.from_path(config_file)
+
+def test_invalid_yaml(tmp_path):
+    config_file = tmp_path / "snk.yaml"
+    config_file.touch()
+    config_file.write_text("logo: test_logo\ninvalid_yaml")
+    with pytest.raises(Exception):
+        SnkConfig.from_path(config_file)
 
 def test_from_dir_with_existing_file(tmp_path):
     config_file = tmp_path / ".snk"