feat(js-connectors): enable transaction levels (prisma#4107)

* feat(js-connectors): enable transaction levels

* chore: fix clippy

* feat: update "rust-postgres" to prisma/rust-postgres@429e760

* chore: allow deprecated cuid

* chore: silence some deprecation warnings

* chore: allow deprecated cuid

* chore: silence some deprecation warnings

* chore: update Cargo.lock

* chore: fix deprecations on chrono

* Revert "chore: update Cargo.lock"

This reverts commit 6e376bc.

* chore: restore insta=1.21.1

* Revert "chore: silence some deprecation warnings"

This reverts commit a8b91ca.

* Revert "feat: update "rust-postgres" to prisma/rust-postgres@429e760"

This reverts commit 9369339.

quaint/src/error.rs

@@ -79,7 +79,7 @@ pub struct Error {
     original_message: Option<String>,
 }
 
-pub(crate) struct ErrorBuilder {
+pub struct ErrorBuilder {
     kind: ErrorKind,
     original_code: Option<String>,
     original_message: Option<String>,
@@ -96,7 +96,7 @@ impl ErrorBuilder {
         self
     }
 
-    pub(crate) fn build(self) -> Error {
+    pub fn build(self) -> Error {
         Error {
             kind: self.kind,
             original_code: self.original_code,
@@ -106,7 +106,7 @@ impl ErrorBuilder {
 }
 
 impl Error {
-    pub(crate) fn builder(kind: ErrorKind) -> ErrorBuilder {
+    pub fn builder(kind: ErrorKind) -> ErrorBuilder {
         ErrorBuilder {
             kind,
             original_code: None,
@@ -298,7 +298,7 @@ impl ErrorKind {
         }
     }
 
-    pub(crate) fn invalid_isolation_level(isolation_level: &IsolationLevel) -> Self {
+    pub fn invalid_isolation_level(isolation_level: &IsolationLevel) -> Self {
         Self::InvalidIsolationLevel(isolation_level.to_string())
     }
 }

query-engine/js-connectors/src/queryable.rs

@@ -7,6 +7,7 @@ use napi::JsObject;
 use psl::datamodel_connector::Flavour;
 use quaint::{
     connector::IsolationLevel,
+    error::{Error, ErrorKind},
     prelude::{Query as QuaintQuery, Queryable as QuaintQueryable, ResultSet, TransactionCapable},
     visitor::{self, Visitor},
     Value,
@@ -131,13 +132,24 @@ impl QuaintQueryable for JsQueryable {
 
     /// Sets the transaction isolation level to given value.
     /// Implementers have to make sure that the passed isolation level is valid for the underlying database.
-    async fn set_tx_isolation_level(&self, _isolation_level: IsolationLevel) -> quaint::Result<()> {
+    async fn set_tx_isolation_level(&self, isolation_level: IsolationLevel) -> quaint::Result<()> {
+        if matches!(isolation_level, IsolationLevel::Snapshot) {
+            return Err(Error::builder(ErrorKind::invalid_isolation_level(&isolation_level)).build());
+        }
+
+        self.raw_cmd(&format!("SET TRANSACTION ISOLATION LEVEL {isolation_level}"))
+            .await?;
+
         Ok(())
     }
 
     /// Signals if the isolation level SET needs to happen before or after the tx BEGIN.
     fn requires_isolation_first(&self) -> bool {
-        false
+        match self.flavour {
+            Flavour::Mysql => true,
+            Flavour::Postgres | Flavour::Sqlite => false,
+            _ => unreachable!(),
+        }
     }
 }