Add null as a specific field type (#2524)

lib/src/sql/kind.rs

@@ -19,6 +19,7 @@ use std::fmt::{self, Display, Formatter};
 #[revisioned(revision = 1)]
 pub enum Kind {
 	Any,
+	Null,
 	Bool,
 	Bytes,
 	Datetime,
@@ -62,6 +63,7 @@ impl Display for Kind {
 	fn fmt(&self, f: &mut Formatter) -> fmt::Result {
 		match self {
 			Kind::Any => f.write_str("any"),
+			Kind::Null => f.write_str("null"),
 			Kind::Bool => f.write_str("bool"),
 			Kind::Bytes => f.write_str("bytes"),
 			Kind::Datetime => f.write_str("datetime"),
@@ -109,6 +111,7 @@ pub fn any(i: &str) -> IResult<&str, Kind> {
 pub fn simple(i: &str) -> IResult<&str, Kind> {
 	alt((
 		map(tag("bool"), |_| Kind::Bool),
+		map(tag("null"), |_| Kind::Null),
 		map(tag("bytes"), |_| Kind::Bytes),
 		map(tag("datetime"), |_| Kind::Datetime),
 		map(tag("decimal"), |_| Kind::Decimal),
@@ -266,6 +269,16 @@ mod tests {
 		assert_eq!(out, Kind::Any);
 	}
 
+	#[test]
+	fn kind_null() {
+		let sql = "null";
+		let res = kind(sql);
+		assert!(res.is_ok());
+		let out = res.unwrap().1;
+		assert_eq!("null", format!("{}", out));
+		assert_eq!(out, Kind::Null);
+	}
+
 	#[test]
 	fn kind_bool() {
 		let sql = "bool";

lib/src/sql/value/value.rs

@@ -1149,6 +1149,7 @@ impl Value {
 		// Attempt to convert to the desired type
 		let res = match kind {
 			Kind::Any => Ok(self),
+			Kind::Null => self.coerce_to_null(),
 			Kind::Bool => self.coerce_to_bool().map(Value::from),
 			Kind::Int => self.coerce_to_int().map(Value::from),
 			Kind::Float => self.coerce_to_float().map(Value::from),
@@ -1179,7 +1180,6 @@ impl Value {
 			},
 			Kind::Option(k) => match self {
 				Self::None => Ok(Self::None),
-				Self::Null => Ok(Self::None),
 				v => v.coerce_to(k),
 			},
 			Kind::Either(k) => {
@@ -1292,6 +1292,19 @@ impl Value {
 		}
 	}
 
+	/// Try to coerce this value to a `null`
+	pub(crate) fn coerce_to_null(self) -> Result<Value, Error> {
+		match self {
+			// Allow any null value
+			Value::Null => Ok(Value::Null),
+			// Anything else raises an error
+			_ => Err(Error::CoerceTo {
+				from: self,
+				into: "null".into(),
+			}),
+		}
+	}
+
 	/// Try to coerce this value to a `bool`
 	pub(crate) fn coerce_to_bool(self) -> Result<bool, Error> {
 		match self {
@@ -1675,6 +1688,7 @@ impl Value {
 		// Attempt to convert to the desired type
 		let res = match kind {
 			Kind::Any => Ok(self),
+			Kind::Null => self.convert_to_null(),
 			Kind::Bool => self.convert_to_bool().map(Value::from),
 			Kind::Int => self.convert_to_int().map(Value::from),
 			Kind::Float => self.convert_to_float().map(Value::from),
@@ -1705,7 +1719,6 @@ impl Value {
 			},
 			Kind::Option(k) => match self {
 				Self::None => Ok(Self::None),
-				Self::Null => Ok(Self::None),
 				v => v.convert_to(k),
 			},
 			Kind::Either(k) => {
@@ -1743,6 +1756,19 @@ impl Value {
 		}
 	}
 
+	/// Try to convert this value to a `null`
+	pub(crate) fn convert_to_null(self) -> Result<Value, Error> {
+		match self {
+			// Allow any boolean value
+			Value::Null => Ok(Value::Null),
+			// Anything else raises an error
+			_ => Err(Error::ConvertTo {
+				from: self,
+				into: "null".into(),
+			}),
+		}
+	}
+
 	/// Try to convert this value to a `bool`
 	pub(crate) fn convert_to_bool(self) -> Result<bool, Error> {
 		match self {

lib/tests/typing.rs

@@ -185,3 +185,137 @@ async fn strict_typing_defined() -> Result<(), Error> {
 	//
 	Ok(())
 }
+
+#[tokio::test]
+async fn strict_typing_none_null() -> Result<(), Error> {
+	let sql = "
+		DEFINE TABLE person SCHEMAFULL;
+		DEFINE FIELD name ON TABLE person TYPE option<string>;
+		UPDATE person:test SET name = 'Tobie';
+		UPDATE person:test SET name = NULL;
+		UPDATE person:test SET name = NONE;
+		--
+		DEFINE TABLE person SCHEMAFULL;
+		DEFINE FIELD name ON TABLE person TYPE option<string | null>;
+		UPDATE person:test SET name = 'Tobie';
+		UPDATE person:test SET name = NULL;
+		UPDATE person:test SET name = NONE;
+		--
+		DEFINE TABLE person SCHEMAFULL;
+		DEFINE FIELD name ON TABLE person TYPE string | null;
+		UPDATE person:test SET name = 'Tobie';
+		UPDATE person:test SET name = NULL;
+		UPDATE person:test SET name = NONE;
+	";
+	let dbs = Datastore::new("memory").await?;
+	let ses = Session::owner().with_ns("test").with_db("test");
+	let res = &mut dbs.execute(sql, &ses, None).await?;
+	assert_eq!(res.len(), 15);
+	//
+	let tmp = res.remove(0).result;
+	assert!(tmp.is_ok());
+	//
+	let tmp = res.remove(0).result;
+	assert!(tmp.is_ok());
+	//
+	let tmp = res.remove(0).result?;
+	let val = Value::parse(
+		"[
+			{
+				id: person:test,
+				name: 'Tobie',
+			}
+		]",
+	);
+	assert_eq!(tmp, val);
+	//
+	let tmp = res.remove(0).result;
+	assert!(matches!(
+		tmp.err(),
+		Some(e) if e.to_string() == "Found NULL for field `name`, with record `person:test`, but expected a option<string>"
+	));
+	//
+	let tmp = res.remove(0).result?;
+	let val = Value::parse(
+		"[
+			{
+				id: person:test,
+			}
+		]",
+	);
+	assert_eq!(tmp, val);
+	//
+	let tmp = res.remove(0).result;
+	assert!(tmp.is_ok());
+	//
+	let tmp = res.remove(0).result;
+	assert!(tmp.is_ok());
+	//
+	let tmp = res.remove(0).result?;
+	let val = Value::parse(
+		"[
+			{
+				id: person:test,
+				name: 'Tobie',
+			}
+		]",
+	);
+	assert_eq!(tmp, val);
+	//
+	let tmp = res.remove(0).result?;
+	let val = Value::parse(
+		"[
+			{
+				id: person:test,
+				name: NULL,
+			}
+		]",
+	);
+	assert_eq!(tmp, val);
+	//
+	let tmp = res.remove(0).result?;
+	let val = Value::parse(
+		"[
+			{
+				id: person:test,
+			}
+		]",
+	);
+	assert_eq!(tmp, val);
+	//
+	let tmp = res.remove(0).result;
+	assert!(tmp.is_ok());
+	//
+	let tmp = res.remove(0).result;
+	assert!(tmp.is_ok());
+	//
+	let tmp = res.remove(0).result?;
+	let val = Value::parse(
+		"[
+			{
+				id: person:test,
+				name: 'Tobie',
+			}
+		]",
+	);
+	assert_eq!(tmp, val);
+	//
+	let tmp = res.remove(0).result?;
+	let val = Value::parse(
+		"[
+			{
+				id: person:test,
+				name: NULL,
+			}
+		]",
+	);
+	assert_eq!(tmp, val);
+	//
+	let tmp = res.remove(0).result;
+	assert!(matches!(
+		tmp.err(),
+		Some(e) if e.to_string() == "Found NONE for field `name`, with record `person:test`, but expected a string | null"
+	));
+	//
+	Ok(())
+}