X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/91f1e7009305109db0bfb6405adbd11357745bfc..85bd5f3272cfc8ba8e54f4f47ea9865d7de62779:/sdk/cwl/arvados_cwl/fsaccess.py

diff --git a/sdk/cwl/arvados_cwl/fsaccess.py b/sdk/cwl/arvados_cwl/fsaccess.py
index 534a675525..93e2819084 100644
--- a/sdk/cwl/arvados_cwl/fsaccess.py
+++ b/sdk/cwl/arvados_cwl/fsaccess.py
@@ -1,3 +1,7 @@
+# Copyright (C) The Arvados Authors. All rights reserved.
+#
+# SPDX-License-Identifier: Apache-2.0
+
 import fnmatch
 import os
 import errno
@@ -91,7 +95,7 @@ class CollectionFsAccess(cwltool.stdfsaccess.StdFsAccess):
 
     def exists(self, fn):
         collection, rest = self.get_collection(fn)
-        if collection:
+        if collection is not None:
             if rest:
                 return collection.exists(rest)
             else:
@@ -149,13 +153,16 @@ class CollectionFsAccess(cwltool.stdfsaccess.StdFsAccess):
             return os.path.realpath(path)
 
 class CollectionFetcher(DefaultFetcher):
-    def __init__(self, cache, session, api_client=None, fs_access=None, num_retries=4):
+    def __init__(self, cache, session, api_client=None, fs_access=None, num_retries=4, overrides=None):
         super(CollectionFetcher, self).__init__(cache, session)
         self.api_client = api_client
         self.fsaccess = fs_access
         self.num_retries = num_retries
+        self.overrides = overrides if overrides else {}
 
     def fetch_text(self, url):
+        if url in self.overrides:
+            return self.overrides[url]
         if url.startswith("keep:"):
             with self.fsaccess.open(url, "r") as f:
                 return f.read()
@@ -166,6 +173,8 @@ class CollectionFetcher(DefaultFetcher):
         return super(CollectionFetcher, self).fetch_text(url)
 
     def check_exists(self, url):
+        if url in self.overrides:
+            return True
         try:
             if url.startswith("http://arvados.org/cwl"):
                 return True