Sync up unique cache paths for Singularity images with cwltool

src/cwl_utils/image_puller.py

@@ -22,7 +22,11 @@ def __init__(
         cmd: str,
         force_pull: bool,
     ) -> None:
-        """Create an ImagePuller."""
+        """
+        Create an ImagePuller.
+
+        req already contains any tag that will be used.
+        """
         self.req = req
         self.save_directory = save_directory
         self.cmd = cmd
@@ -86,14 +90,14 @@ def save_docker_image(self) -> None:
 class SingularityImagePuller(ImagePuller):
     """Pull docker image with Singularity."""
 
-    CHARS_TO_REPLACE = ["/", ":"]
-    NEW_CHAR = "_"
+    CHARS_TO_REPLACE = ["_", "/"]
+    NEW_STRINGS = ["___", "_s_"]
 
     def get_image_name(self) -> str:
         """Determine the file name appropriate to the installed version of Singularity."""
         image_name = self.req
-        for char in self.CHARS_TO_REPLACE:
-            image_name = image_name.replace(char, self.NEW_CHAR)
+        for char, replacement in zip(self.CHARS_TO_REPLACE, self.NEW_STRINGS):
+            image_name = image_name.replace(char, replacement)
         if is_singularity_version_2_6():
             suffix = ".img"
         elif is_singularity_version_3_or_newer():

src/cwl_utils/tests/test_image_puller.py

@@ -0,0 +1,33 @@
+# SPDX-License-Identifier: Apache-2.0
+"""Tests for classes for docker-extract."""
+
+from cwl_utils.image_puller import SingularityImagePuller
+from cwl_utils.singularity import get_version as get_singularity_version
+from cwl_utils.singularity import is_version_2_6 as is_singularity_version_2_6
+from cwl_utils.singularity import (
+    is_version_3_or_newer as is_singularity_version_3_or_newer,
+)
+
+from .util import needs_singularity
+
+
+@needs_singularity
+class TestSingularityImagePuller:
+    """Tests for SingularityImagePuller."""
+
+    def test_get_image_name_matches_cwltool(self) -> None:
+        """Make sure image names generated match those expected by cwltool."""
+        if is_singularity_version_2_6():
+            suffix = ".img"
+        elif is_singularity_version_3_or_newer():
+            suffix = ".sif"
+        else:
+            raise Exception(
+                f"Don't know how to handle this version of singularity: {get_singularity_version()}."
+            )
+
+        def get_name(s: str) -> str:
+            return SingularityImagePuller(s, None, "", False).get_image_name()
+
+        assert get_name("some_name/repo:123") == f"some___name_s_repo:123{suffix}"
+        assert get_name("some/name_repo:123") == f"some_s_name___repo:123{suffix}"