fix: raise error if writing to url

This is in DefaultStacIO ... other StacIOs could support writing to urls, if
they want.

Author: gadomski

CHANGELOG.md

@@ -17,6 +17,7 @@
 - Removed documentation references to `to_dict` methods returning JSON ([#1074](https://github.com/stac-utils/pystac/pull/1074))
 - Expand support for previous extension schema URIs ([#1091](https://github.com/stac-utils/pystac/pull/1091))
 - Use `pyproject.toml` instead of `setup.py` ([#1100](https://github.com/stac-utils/pystac/pull/1100))
+- `DefaultStacIO` now raises an error if it tries to write to a non-local url ([#1107](https://github.com/stac-utils/pystac/pull/1107))
 
 ### Deprecated
 

pystac/stac_io.py

@@ -326,6 +326,8 @@ def write_text_to_href(self, href: str, txt: str) -> None:
             href : The path to which the file will be written.
             txt : The string content to write to the file.
         """
+        if _is_url(href):
+            raise NotImplementedError("DefaultStacIO cannot write to urls")
         href = os.fspath(href)
         dirname = os.path.dirname(href)
         if dirname != "" and not os.path.isdir(dirname):

tests/test_stac_io.py

@@ -2,6 +2,7 @@
 import os
 import tempfile
 import unittest
+from pathlib import Path
 
 import pytest
 
@@ -142,3 +143,10 @@ def test_retry_stac_io_404() -> None:
             "https://planetarycomputer.microsoft.com"
             "/api/stac/v1/collections/not-a-collection-id"
         )
+
+
+def test_save_http_href_errors(tmp_path: Path) -> None:
+    catalog = pystac.Catalog(id="test-catalog", description="")
+    catalog.set_self_href("http://pystac.test/catalog.json")
+    with pytest.raises(NotImplementedError):
+        catalog.save_object()