From a337060067adf5bcb54fb88ca9674e85349a1501 Mon Sep 17 00:00:00 2001
From: "John T. Wodder II" <git@varonathe.org>
Date: Tue, 13 Apr 2021 09:45:17 -0400
Subject: [PATCH] Fix & test for downloading by asset ID URL

---
 dandi/download.py            | 25 +++++++++++++++++++------
 dandi/tests/test_download.py | 17 +++++++++++++++++
 2 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/dandi/download.py b/dandi/download.py
index bff6dfe87..be1c09cd1 100644
--- a/dandi/download.py
+++ b/dandi/download.py
@@ -163,12 +163,25 @@ def download_generator(
             elif isinstance(client, DandiAPIClient):
                 # At least according to our 0.1.0 state of v1
                 # https://github.com/dandi/dandi-publish/issues/79
-                down_args = (
-                    dandiset["dandiset"]["identifier"],
-                    dandiset["version"],
-                    asset["asset_id"],
-                )
-                metadata = client.get_asset(*down_args)
+                if "asset_id" in asset_id:
+                    down_args = (
+                        dandiset["dandiset"]["identifier"],
+                        dandiset["version"],
+                        asset_id["asset_id"],
+                    )
+                    metadata = asset
+                    asset = {
+                        "path": metadata["path"],
+                        "size": metadata["contentSize"],
+                        "metadata": metadata,
+                    }
+                else:
+                    down_args = (
+                        dandiset["dandiset"]["identifier"],
+                        dandiset["version"],
+                        asset["asset_id"],
+                    )
+                    metadata = client.get_asset(*down_args)
                 d = metadata.get("digest", {})
                 if "dandi:dandi-etag" in d:
                     digests = {"dandi-etag": d["dandi:dandi-etag"]}
diff --git a/dandi/tests/test_download.py b/dandi/tests/test_download.py
index 8c34631c0..3198ab10e 100644
--- a/dandi/tests/test_download.py
+++ b/dandi/tests/test_download.py
@@ -176,3 +176,20 @@ def test_download_item(local_dandi_api, text_dandiset, tmp_path):
         tmp_path / "coconut.txt"
     ]
     assert (tmp_path / "coconut.txt").read_text() == "Coconut\n"
+
+
+def test_download_asset_id(local_dandi_api, text_dandiset, tmp_path):
+    dandiset_id = text_dandiset["dandiset_id"]
+    asset = local_dandi_api["client"].get_asset_bypath(
+        dandiset_id, "draft", "subdir2/coconut.txt"
+    )
+    assert asset is not None
+    download(
+        f"{local_dandi_api['instance'].api}/dandisets/{dandiset_id}/versions"
+        f"/draft/assets/{asset['asset_id']}/download/",
+        tmp_path,
+    )
+    assert list(map(Path, find_files(r".*", paths=[tmp_path], dirs=True))) == [
+        tmp_path / "coconut.txt"
+    ]
+    assert (tmp_path / "coconut.txt").read_text() == "Coconut\n"