Support yyyy-MM-DD string for datetimes

python/pydantic_core/core_schema.py

@@ -3787,6 +3787,7 @@ def definition_reference_schema(
     'datetime_type',
     'datetime_parsing',
     'datetime_object_invalid',
+    'datetime_from_date_parsing',
     'datetime_past',
     'datetime_future',
     'timezone_naive',

src/errors/types.rs

@@ -338,6 +338,9 @@ error_types! {
     DatetimeObjectInvalid {
         error: {ctx_type: String, ctx_fn: field_from_context},
     },
+    DatetimeFromDateParsing {
+        error: {ctx_type: Cow<'static, str>, ctx_fn: cow_field_from_context<String, _>},
+    },
     DatetimePast {},
     DatetimeFuture {},
     // ---------------------
@@ -529,6 +532,7 @@ impl ErrorType {
             Self::DatetimeType {..} => "Input should be a valid datetime",
             Self::DatetimeParsing {..} => "Input should be a valid datetime, {error}",
             Self::DatetimeObjectInvalid {..} => "Invalid datetime object, got {error}",
+            Self::DatetimeFromDateParsing {..} => "Input should be a valid datetime or date, {error}",
             Self::DatetimePast {..} => "Input should be in the past",
             Self::DatetimeFuture {..} => "Input should be in the future",
             Self::TimezoneNaive {..} => "Input should not have timezone info",
@@ -684,6 +688,7 @@ impl ErrorType {
             Self::DateFromDatetimeParsing { error, .. } => render!(tmpl, error),
             Self::TimeParsing { error, .. } => render!(tmpl, error),
             Self::DatetimeParsing { error, .. } => render!(tmpl, error),
+            Self::DatetimeFromDateParsing { error, .. } => render!(tmpl, error),
             Self::DatetimeObjectInvalid { error, .. } => render!(tmpl, error),
             Self::TimezoneOffset {
                 tz_expected, tz_actual, ..

src/validators/datetime.rs

@@ -2,7 +2,7 @@ use pyo3::intern;
 use pyo3::once_cell::GILOnceCell;
 use pyo3::prelude::*;
 use pyo3::types::{PyDateTime, PyDict, PyString};
-use speedate::DateTime;
+use speedate::{DateTime, Time};
 use std::cmp::Ordering;
 use strum::EnumMessage;
 
@@ -65,9 +65,12 @@ impl Validator for DateTimeValidator {
         state: &mut ValidationState,
     ) -> ValResult<PyObject> {
         let strict = state.strict_or(self.strict);
-        let datetime = input
-            .validate_datetime(strict, self.microseconds_precision)?
-            .unpack(state);
+        let datetime = match input.validate_datetime(strict, self.microseconds_precision) {
+            Ok(val_match) => val_match.unpack(state),
+            // if the error was a parsing error, in lax mode we allow dates and add the time 00:00:00
+            Err(line_errors @ ValError::LineErrors(..)) if !strict => datetime_from_date(input)?.ok_or(line_errors)?,
+            Err(otherwise) => return Err(otherwise),
+        };
         if let Some(constraints) = &self.constraints {
             // if we get an error from as_speedate, it's probably because the input datetime was invalid
             // specifically had an invalid tzinfo, hence here we return a validation error
@@ -132,6 +135,48 @@ impl Validator for DateTimeValidator {
     }
 }
 
+/// In lax mode, if the input is not a datetime, we try parsing the input as a date and add the "00:00:00" time.
+///
+/// Ok(None) means that this is not relevant to datetimes (the input was not a date nor a string)
+fn datetime_from_date<'data>(input: &'data impl Input<'data>) -> Result<Option<EitherDateTime<'data>>, ValError> {
+    let either_date = match input.validate_date(false) {
+        Ok(val_match) => val_match.into_inner(),
+        // if the error was a parsing error, update the error type from DateParsing to DatetimeFromDateParsing
+        Err(ValError::LineErrors(mut line_errors)) => {
+            if line_errors.iter_mut().fold(false, |has_parsing_error, line_error| {
+                if let ErrorType::DateParsing { error, .. } = &mut line_error.error_type {
+                    line_error.error_type = ErrorType::DatetimeFromDateParsing {
+                        error: std::mem::take(error),
+                        context: None,
+                    };
+                    true
+                } else {
+                    has_parsing_error
+                }
+            }) {
+                return Err(ValError::LineErrors(line_errors));
+            }
+            return Ok(None);
+        }
+        // for any other error, don't return it
+        Err(_) => return Ok(None),
+    };
+
+    let zero_time = Time {
+        hour: 0,
+        minute: 0,
+        second: 0,
+        microsecond: 0,
+        tz_offset: Some(0),
+    };
+
+    let datetime = DateTime {
+        date: either_date.as_raw()?,
+        time: zero_time,
+    };
+    Ok(Some(EitherDateTime::Raw(datetime)))
+}
+
 #[derive(Debug, Clone)]
 struct DateTimeConstraints {
     le: Option<DateTime>,

tests/test_errors.py

@@ -332,6 +332,7 @@ def f(input_value, info):
     ('time_parsing', 'Input should be in a valid time format, foobar', {'error': 'foobar'}),
     ('datetime_type', 'Input should be a valid datetime', None),
     ('datetime_parsing', 'Input should be a valid datetime, foobar', {'error': 'foobar'}),
+    ('datetime_from_date_parsing', 'Input should be a valid datetime or date, foobar', {'error': 'foobar'}),
     ('datetime_object_invalid', 'Invalid datetime object, got foobar', {'error': 'foobar'}),
     ('datetime_past', 'Input should be in the past', None),
     ('datetime_future', 'Input should be in the future', None),

tests/test_hypothesis.py

@@ -47,11 +47,11 @@ def test_datetime_binary(datetime_schema, data):
     except ValidationError as exc:
         assert exc.errors(include_url=False) == [
             {
-                'type': 'datetime_parsing',
+                'type': 'datetime_from_date_parsing',
                 'loc': (),
-                'msg': IsStr(regex='Input should be a valid datetime, .+'),
+                'msg': IsStr(regex='Input should be a valid datetime or date, .+'),
                 'input': IsBytes(),
-                'ctx': {'error': IsStr()},
+                'ctx': {'error': 'input is too short'},
             }
         ]
 

tests/validators/test_datetime.py

@@ -19,6 +19,7 @@
     [
         (datetime(2022, 6, 8, 12, 13, 14), datetime(2022, 6, 8, 12, 13, 14)),
         (date(2022, 6, 8), datetime(2022, 6, 8)),
+        ('2022-01-01', datetime(2022, 1, 1, 0, 0, 0, tzinfo=timezone.utc)),
         ('2022-06-08T12:13:14', datetime(2022, 6, 8, 12, 13, 14)),
         ('1000000000000', datetime(2001, 9, 9, 1, 46, 40, tzinfo=timezone.utc)),
         (b'2022-06-08T12:13:14', datetime(2022, 6, 8, 12, 13, 14)),
@@ -36,8 +37,14 @@
         (float('nan'), Err('Input should be a valid datetime, NaN values not permitted [type=datetime_parsing,')),
         (float('inf'), Err('Input should be a valid datetime, dates after 9999')),
         (float('-inf'), Err('Input should be a valid datetime, dates before 1600')),
-        ('-', Err('Input should be a valid datetime, input is too short [type=datetime_parsing,')),
-        ('+', Err('Input should be a valid datetime, input is too short [type=datetime_parsing,')),
+        ('-', Err('Input should be a valid datetime or date, input is too short [type=datetime_from_date_parsing,')),
+        ('+', Err('Input should be a valid datetime or date, input is too short [type=datetime_from_date_parsing,')),
+        (
+            '2022-02-30',
+            Err(
+                'Input should be a valid datetime or date, day value is outside expected range [type=datetime_from_date_parsing,'
+            ),
+        ),
     ],
 )
 def test_datetime(input_value, expected):
@@ -119,7 +126,9 @@ def test_keep_tz_bound():
         (1655205632.331557, datetime(2022, 6, 14, 11, 20, 32, microsecond=331557, tzinfo=timezone.utc)),
         (
             '2022-06-08T12:13:14+24:00',
-            Err('Input should be a valid datetime, timezone offset must be less than 24 hours [type=datetime_parsing,'),
+            Err(
+                'Input should be a valid datetime or date, unexpected extra characters at the end of the input [type=datetime_from_date_parsing,'
+            ),
         ),
         (True, Err('Input should be a valid datetime [type=datetime_type')),
         (None, Err('Input should be a valid datetime [type=datetime_type')),