Enhance CSV metadata with error tracking for mosaics and tiles

tests/test_download_result.py

@@ -0,0 +1,36 @@
+"""Tests for spruce.download_result classification."""
+
+import requests
+
+from spruce.download_result import (
+    PERMANENT_MISSING,
+    TRANSIENT,
+    UNKNOWN,
+    classify_http_error,
+    error_code_str,
+)
+
+
+def test_classify_404_permanent():
+    assert classify_http_error(404, None) == PERMANENT_MISSING
+
+
+def test_classify_410_permanent():
+    assert classify_http_error(410, None) == PERMANENT_MISSING
+
+
+def test_classify_503_transient():
+    assert classify_http_error(503, None) == TRANSIENT
+
+
+def test_classify_timeout_transient():
+    assert classify_http_error(None, requests.Timeout()) == TRANSIENT
+
+
+def test_classify_unknown_4xx():
+    assert classify_http_error(403, None) == UNKNOWN
+
+
+def test_error_code_str():
+    assert error_code_str(None) == ""
+    assert error_code_str(404) == "404"