fix: use sqlite3_value_text for REGEXP to match SQLite coercion (#4203)

Use sqlite3_value_text() instead of checking sqlite3_value_type()
first, matching SQLite's documented text affinity coercion for
the REGEXP operator. NULL values still return NULL.

Closes #4190

Author: joaquinhuigomez

sqlx-sqlite/src/regexp.rs

@@ -136,8 +136,11 @@ unsafe fn get_regex_from_arg(
     Some(regex)
 }
 
-/// Get a text reference of the value of `arg`. If this value is not a string value, an error is printed and `None` is
-/// returned.
+/// Get a text reference of the value of `arg`. Returns `None` for NULL values.
+///
+/// For non-NULL values, `sqlite3_value_text()` is called directly, which lets SQLite
+/// coerce INTEGER, REAL, and BLOB values to their text representation. This matches
+/// the coercion behavior documented at <https://www.sqlite.org/c3ref/value_blob.html>.
 ///
 /// The returned `&str` is valid for lifetime `'a` which can be determined by the caller. This lifetime should **not**
 /// outlive `ctx`.
@@ -146,20 +149,19 @@ unsafe fn get_text_from_arg<'a>(
     arg: *mut ffi::sqlite3_value,
 ) -> Option<&'a str> {
     let ty = ffi::sqlite3_value_type(arg);
-    if ty == ffi::SQLITE_TEXT {
-        let ptr = ffi::sqlite3_value_text(arg);
-        let len = ffi::sqlite3_value_bytes(arg);
-        let slice = std::slice::from_raw_parts(ptr.cast(), len as usize);
-        match std::str::from_utf8(slice) {
-            Ok(result) => Some(result),
-            Err(e) => {
-                log::error!("Incoming text is not valid UTF8: {e:?}");
-                ffi::sqlite3_result_error_code(ctx, ffi::SQLITE_CONSTRAINT_FUNCTION);
-                None
-            }
+    if ty == ffi::SQLITE_NULL {
+        return None;
+    }
+    let ptr = ffi::sqlite3_value_text(arg);
+    let len = ffi::sqlite3_value_bytes(arg);
+    let slice = std::slice::from_raw_parts(ptr.cast(), len as usize);
+    match std::str::from_utf8(slice) {
+        Ok(result) => Some(result),
+        Err(e) => {
+            log::error!("Incoming text is not valid UTF8: {e:?}");
+            ffi::sqlite3_result_error_code(ctx, ffi::SQLITE_CONSTRAINT_FUNCTION);
+            None
         }
-    } else {
-        None
     }
 }
 
@@ -222,6 +224,52 @@ mod tests {
         assert!(result.is_empty());
     }
 
+    #[sqlx::test]
+    async fn test_regexp_coerces_non_text_values() {
+        let mut conn = crate::SqliteConnectOptions::from_str("sqlite://:memory:")
+            .unwrap()
+            .with_regexp()
+            .connect()
+            .await
+            .unwrap();
+
+        // INTEGER coercion
+        let result: Option<i32> = sqlx::query_scalar("SELECT 123 REGEXP '23'")
+            .fetch_one(&mut conn)
+            .await
+            .unwrap();
+        assert_eq!(result, Some(1));
+
+        // REAL coercion
+        let result: Option<i32> = sqlx::query_scalar("SELECT 12.5 REGEXP '12\\.5'")
+            .fetch_one(&mut conn)
+            .await
+            .unwrap();
+        assert_eq!(result, Some(1));
+
+        // INTEGER column
+        sqlx::query("CREATE TABLE int_test (x INTEGER NOT NULL)")
+            .execute(&mut conn)
+            .await
+            .unwrap();
+        sqlx::query("INSERT INTO int_test VALUES (123), (45)")
+            .execute(&mut conn)
+            .await
+            .unwrap();
+        let rows: Vec<i64> = sqlx::query_scalar("SELECT x FROM int_test WHERE x REGEXP '23'")
+            .fetch_all(&mut conn)
+            .await
+            .unwrap();
+        assert_eq!(rows, vec![123]);
+
+        // NULL should return NULL, not match
+        let result: Option<i32> = sqlx::query_scalar("SELECT NULL REGEXP '.*'")
+            .fetch_one(&mut conn)
+            .await
+            .unwrap();
+        assert_eq!(result, None);
+    }
+
     #[sqlx::test]
     async fn test_invalid_regexp_should_fail() {
         let mut conn = test_db().await;