Make str_to_interval not return a tuple for single-value input (#692)

* Do not return tuple for single-value input

* Add PR reference to changelog

* update from main

---------

Co-authored-by: vincentsarago <[email protected]>

CHANGES.md

@@ -7,12 +7,15 @@
 * Switch from `fastapi` to `fastapi-slim` to avoid installing unwanted dependencies. ([#687](https://github.com/stac-utils/stac-fastapi/pull/687))
 * Replace Enum with `Literal` for `FilterLang`. ([#686](https://github.com/stac-utils/stac-fastapi/pull/686))
 * Update stac-pydantic requirement to `~3.1` ([#697](https://github.com/stac-utils/stac-fastapi/pull/697))
-* Fix datetime interval for GET Search when passing a single value ([#697](https://github.com/stac-utils/stac-fastapi/pull/697))
 
 ### Removed
 
 * Pystac as it was just used for a datetime to string function. ([#690](https://github.com/stac-utils/stac-fastapi/pull/690))
 
+### Fixed
+
+* Make `str_to_interval` not return a tuple for single-value input (fixing `datetime` argument as passed to `get_search`). ([#692](https://github.com/stac-utils/stac-fastapi/pull/692))
+
 ## [3.0.0a0] - 2024-05-06
 
 ### Added

stac_fastapi/types/stac_fastapi/types/rfc3339.py

@@ -94,16 +94,17 @@ def parse_single_date(date_str: str) -> datetime:
 
 def str_to_interval(interval: Optional[str]) -> Optional[DateTimeType]:
     """
-    Extract a tuple of datetime objects from an interval string defined by the OGC API.
-    The interval can either be a single datetime or a range with start and end datetime.
+    Extract a single datetime object or a tuple of datetime objects from an
+    interval string defined by the OGC API. The interval can either be a
+    single datetime or a range with start and end datetime.
 
     Args:
         interval (Optional[str]): The interval string to convert to datetime objects,
         or None if no datetime is specified.
 
     Returns:
-        Optional[DateTimeType]: A tuple of datetime.datetime objects or
-        None if input is None.
+        Optional[DateTimeType]: A single datetime.datetime object, a tuple of
+        datetime.datetime objects, or None if input is None.
 
     Raises:
         HTTPException: If the string is not valid for various reasons such as being empty,
@@ -122,11 +123,11 @@ def str_to_interval(interval: Optional[str]) -> Optional[DateTimeType]:
             detail="Interval string contains more than one forward slash.",
         )
 
-    if len(values) == 1:
-        values = [values[0], values[0]]
-
     try:
         start = parse_single_date(values[0]) if values[0] not in ["..", ""] else None
+        if len(values) == 1:
+            return start
+
         end = (
             parse_single_date(values[1])
             if len(values) > 1 and values[1] not in ["..", ""]

stac_fastapi/types/tests/test_rfc3339.py

@@ -1,4 +1,4 @@
-from datetime import timezone
+from datetime import datetime, timezone
 
 import pytest
 from fastapi import HTTPException
@@ -86,31 +86,49 @@ def test_parse_valid_str_to_datetime(test_input):
 
 
 @pytest.mark.parametrize("test_input", invalid_intervals)
-def test_parse_invalid_interval_to_datetime(test_input):
+def test_str_to_interval_with_invalid_interval(test_input):
     with pytest.raises(HTTPException) as exc_info:
         str_to_interval(test_input)
     assert (
         exc_info.value.status_code == 400
-    ), "Should return a 400 status code for invalid intervals"
+    ), "str_to_interval should return a 400 status code for invalid interval"
 
 
-@pytest.mark.parametrize("test_input", valid_intervals)
-def test_parse_valid_interval_to_datetime(test_input):
-    assert str_to_interval(test_input)
+@pytest.mark.parametrize("test_input", invalid_datetimes)
+def test_str_to_interval_with_invalid_datetime(test_input):
+    with pytest.raises(HTTPException) as exc_info:
+        str_to_interval(test_input)
+    assert (
+        exc_info.value.status_code == 400
+    ), "str_to_interval should return a 400 status code for invalid datetime"
 
 
-def test_now_functions() -> None:
-    now1 = now_in_utc()
-    now2 = now_in_utc()
+@pytest.mark.parametrize("test_input", valid_intervals)
+def test_str_to_interval_with_valid_interval(test_input):
+    assert isinstance(
+        str_to_interval(test_input), tuple
+    ), "str_to_interval should return tuple for multi-value input"
 
-    assert now1 < now2
-    assert now1.tzinfo == timezone.utc
 
-    rfc3339_str_to_datetime(now_to_rfc3339_str())
+@pytest.mark.parametrize("test_input", valid_datetimes)
+def test_str_to_interval_with_valid_datetime(test_input):
+    assert isinstance(
+        str_to_interval(test_input), datetime
+    ), "str_to_interval should return single datetime for single-value input"
 
 
 def test_str_to_interval_with_none():
     """Test that str_to_interval returns None when provided with None."""
     assert (
         str_to_interval(None) is None
     ), "str_to_interval should return None when input is None"
+
+
+def test_now_functions() -> None:
+    now1 = now_in_utc()
+    now2 = now_in_utc()
+
+    assert now1 < now2
+    assert now1.tzinfo == timezone.utc
+
+    rfc3339_str_to_datetime(now_to_rfc3339_str())