feat(qc): make placeholders typed at JSON protocol level (#5738)

Require placeholder types to be specified in the JSON
protocol representation of the placholders and parse them in
`JsonProtocolAdapter`.

Author: aqrln

libs/prisma-value/src/lib.rs

@@ -129,6 +129,7 @@ impl std::fmt::Display for PrismaValueType {
 #[derive(Debug, Clone, Eq, PartialEq, Hash, Deserialize, PartialOrd, Ord)]
 pub struct Placeholder {
     pub name: Cow<'static, str>,
+    #[serde(flatten)]
     pub r#type: PrismaValueType,
 }
 

query-compiler/query-compiler-playground/src/main.rs

@@ -45,7 +45,10 @@ pub fn main() -> anyhow::Result<()> {
                 "where": {
                     "email": {
                         "$type": "Param",
-                        "value": "userEmail"
+                        "value": {
+                            "name": "userEmail",
+                            "type": "String"
+                        }
                     }
                 }
             },

query-compiler/request-handlers/src/protocols/json/protocol_adapter.rs

@@ -6,7 +6,7 @@ use query_core::{
     constants::custom_types,
     schema::{ObjectType, OutputField, QuerySchema},
 };
-use query_structure::{Field, PrismaValue, PrismaValueType, decode_bytes, parse_datetime, prelude::ParentContainer};
+use query_structure::{Field, PrismaValue, decode_bytes, parse_datetime, prelude::ParentContainer};
 use serde_json::Value as JsonValue;
 use std::str::FromStr;
 
@@ -244,15 +244,11 @@ impl<'a> JsonProtocolAdapter<'a> {
                     Ok(ArgumentValue::FieldRef(values))
                 }
                 Some(custom_types::PARAM) => {
-                    let name = obj
-                        .get(custom_types::VALUE)
-                        .and_then(|v| v.as_str())
-                        .ok_or_else(build_err)?
-                        .to_owned();
-
-                    let placeholder = PrismaValue::placeholder(name, PrismaValueType::Any);
+                    let value = obj.remove(custom_types::VALUE).ok_or_else(build_err)?;
+                    let placeholder =
+                        serde_json::from_value(value).map_err(|e| HandlerError::QueryConversion(e.to_string()))?;
 
-                    Ok(ArgumentValue::Scalar(placeholder))
+                    Ok(ArgumentValue::Scalar(PrismaValue::Placeholder(placeholder)))
                 }
                 _ => {
                     let values = obj