Enable transactional endpoint evaluation.

cli/tests/lit/transaction.lit

@@ -0,0 +1,82 @@
+# SPDX-FileCopyrightText: © 2021 ChiselStrike <info@chiselstrike.com>
+
+# RUN: sh -e @file
+
+cat << EOF > "$TEMPDIR/models/types.ts"
+export class Person extends Chisel.ChiselEntity {
+   name: string = "";
+}
+EOF
+
+cat << EOF > "$TEMPDIR/endpoints/store_person.js"
+import { Person } from "../types.ts";
+
+export default async function chisel(req: Request) {
+    const req_json = await req.json();
+
+    let p = new Person();
+    p.name = req_json.name;
+    await p.save();
+
+    if (req_json.command == "die with honor") {
+        throw "Let's see if transaction gets cancelled";
+    }
+
+    return new Response('Mission acomplished');
+}
+EOF
+
+cat << EOF > "$TEMPDIR/endpoints/retrieve_all.ts"
+import { Person } from "../models/types.ts";
+
+export default async function chisel(req: Request) {
+    let resp = "[";
+    for await (let p of Person.cursor()) {
+        resp += p.name + " ";
+    }
+    resp += "]";
+    return new Response(resp);
+}
+EOF
+
+cat << EOF > "$TEMPDIR/endpoints/write_and_read.ts"
+import { Person } from "../models/types.ts";
+
+export default async function chisel(req: Request) {
+    let p = new Person();
+    p.name = "ThisIsTheBestName";
+    await p.save();
+
+    let resp = "[";
+    for await (let p of Person.cursor()) {
+        resp += p.name + " ";
+    }
+    resp += "]";
+
+    return new Response(resp);
+}
+EOF
+
+cd "$TEMPDIR"
+$CHISEL apply
+
+$CURL -X POST --data '{ "name": "Adalbrecht" }' $CHISELD_HOST/dev/store_person
+# CHECK: Mission acomplished
+
+$CURL $CHISELD_HOST/dev/retrieve_all
+# CHECK: HTTP/1.1 200 OK
+# CHECK: [Adalbrecht ]
+
+$CURL -X POST --data '{
+    "name": "Ruprt",
+    "command": "die with honor"
+}' $CHISELD_HOST/dev/store_person
+# CHECK: HTTP/1.1 500 Internal Server Error
+
+$CURL $CHISELD_HOST/dev/retrieve_all
+# CHECK: HTTP/1.1 200 OK
+# CHECK: [Adalbrecht ]
+
+$CURL -X POST $CHISELD_HOST/dev/write_and_read
+# CHECK: HTTP/1.1 200 OK
+# CHECK: [Adalbrecht ThisIsTheBestName ]

docusaurus/docs/data-access.md

@@ -212,7 +212,7 @@ The `findMany()` method is convenient, but also problematic if you have a lot of
 entities stored because loading them can take a lot of time and memory. In future
 releases of ChiselStrike, the runtime will enforce a maximum number of entities
 `findMany()` can return and also enforce timeouts at the data store level. The
-runtime will also provide optional pagination for the `findMany()` method. 
+runtime will also provide optional pagination for the `findMany()` method.
 :::
 
 ## Cursors
@@ -270,3 +270,15 @@ The methods provided by `ChiselCursor` are outlined in the following table.
 The `ChiselCursor` interface is still work-in-progress. For example, methods such as `skip()`,  `map()`, and `reduce()` are planned for future releases.
 Also, the current implementation of `filter()` takes a _restriction object_, but future ChiselStrike runtimes will allow you to write filter functions using TypeScript, which are automatically converted to efficient database queries in many cases.
 :::
+
+## Transacitons
+
+We currently support implicit transactional evaluation. The transaction is created before ChiselStrike
+starts evaluating your endpoint and is automatically committed after your endpoint ends and we generate
+the HTTP response. In case your endpoint returns a stream, any database-related operation done within
+stream generation code will happen outside of the transaction and can result in a crash.
+
+If your code crashes or explicitly throws exception that is not caught, ChiselStrike rollbacks the
+transaction automatically.
+
+Explicit user-controlled transactions are coming soon.

docusaurus/docs/known_issues.md

@@ -19,11 +19,6 @@ There are also other potential issues with Node imports that are [well-known](ht
 While we do plan to provide you with a better experience in the future, for now if you do
 want to use external modules, browser-style should work.
 
-* **Transactions:** ChiselStrike aims to fully support transactions at the endpoint boundary and,
-at a later date, with user-defined granularity (for advanced users). There is a known bug with
-that, though: endpoints should be serialized so RMW is write, but transactions won't be rolled
-back if there is an exception in the endpoint and it doesn't complete.
-
 * **Nested models:** (Also known as relationships.) With the exception of the special `OAuthUser`
 model, it is not possible to embed a model inside another yet. The code to persist nested models
 works, but the code to retrieve them doesn't. 🤷‍♂️

server/src/auth.rs

@@ -65,7 +65,7 @@ async fn insert_user_into_db(username: &str) -> Result<String> {
     }
     user.insert("username".into(), json!(username));
     query_engine
-        .add_row(&oauth_user_type, &user)
+        .add_row(&oauth_user_type, &user, None)
         .await?
         .get("id")
         .ok_or_else(|| anyhow!("Didn't get user ID from storing a user."))?

server/src/db.rs

@@ -6,6 +6,7 @@ use crate::policies::FieldPolicies;
 use crate::query::engine;
 use crate::query::engine::new_query_results;
 use crate::query::engine::SqlStream;
+use crate::query::engine::TransactionStatic;
 use crate::runtime;
 use crate::types::{Field, ObjectType, Type, TypeSystem, TypeSystemError, OAUTHUSER_TYPE_NAME};
 use crate::JsonObject;
@@ -21,7 +22,6 @@ use itertools::Itertools;
 use pin_project::pin_project;
 use serde_json::value::Value;
 use sqlx::any::AnyRow;
-use sqlx::AnyPool;
 use std::collections::HashMap;
 use std::collections::HashSet;
 use std::pin::Pin;
@@ -286,7 +286,7 @@ fn sql_where_for_match_login(
 }
 
 fn sql_backing_store(
-    pool: &AnyPool,
+    tr: TransactionStatic,
     columns: Vec<(String, Type)>,
     limit_str: &str,
     ty: Arc<ObjectType>,
@@ -313,7 +313,7 @@ fn sql_backing_store(
     if policies.transforms.is_empty() {
         return Query::Sql(query);
     }
-    let inner = new_query_results(query, pool);
+    let inner = new_query_results(query, tr);
     let pstream = Box::pin(PolicyApplyingStream {
         inner,
         policies,
@@ -405,14 +405,14 @@ fn join_stream(columns: &[(String, Type)], left: SqlStream, right: SqlStream) ->
 }
 
 fn sql_filter(
-    pool: &AnyPool,
+    tr: TransactionStatic,
     columns: Vec<(String, Type)>,
     limit_str: &str,
     alias_count: &mut u32,
     inner: Relation,
     restrictions: Vec<Restriction>,
 ) -> Query {
-    let inner_sql = sql_impl(pool, inner, alias_count);
+    let inner_sql = sql_impl(tr, inner, alias_count);
     let inner_sql = match inner_sql {
         Query::Sql(s) => s,
         Query::Stream(s) => return filter_stream(s, columns, restrictions),
@@ -450,8 +450,8 @@ pub(crate) fn sql_restrictions(restrictions: Vec<Restriction>) -> String {
     })
 }
 
-fn to_stream(pool: &AnyPool, s: String, columns: Vec<(String, Type)>) -> SqlStream {
-    let inner = new_query_results(s, pool);
+fn to_stream(tr: TransactionStatic, s: String, columns: Vec<(String, Type)>) -> SqlStream {
+    let inner = new_query_results(s, tr);
     Box::pin(PolicyApplyingStream {
         inner,
         policies: FieldPolicies::default(),
@@ -460,7 +460,7 @@ fn to_stream(pool: &AnyPool, s: String, columns: Vec<(String, Type)>) -> SqlStre
 }
 
 fn sql_join(
-    pool: &AnyPool,
+    tr: TransactionStatic,
     columns: &[(String, Type)],
     limit_str: &str,
     alias_count: &mut u32,
@@ -487,15 +487,15 @@ fn sql_join(
     // FIXME: Optimize the case of table.left or table.right being just
     // a BackingStore with all fields. The database probably doesn't
     // care, but will make the logs cleaner.
-    let lsql = sql_impl(pool, left, alias_count);
-    let rsql = sql_impl(pool, right, alias_count);
+    let lsql = sql_impl(tr.clone(), left, alias_count);
+    let rsql = sql_impl(tr.clone(), right, alias_count);
     let (lsql, rsql) = match (lsql, rsql) {
         (Query::Sql(l), Query::Sql(r)) => (l, r),
         (Query::Stream(l), Query::Sql(r)) => {
-            return join_stream(columns, l, to_stream(pool, r, right_columns))
+            return join_stream(columns, l, to_stream(tr, r, right_columns))
         }
         (Query::Sql(l), Query::Stream(r)) => {
-            return join_stream(columns, to_stream(pool, l, left_columns), r)
+            return join_stream(columns, to_stream(tr, l, left_columns), r)
         }
         (Query::Stream(l), Query::Stream(r)) => return join_stream(columns, l, r),
     };
@@ -517,34 +517,34 @@ fn sql_join(
     ))
 }
 
-fn sql_impl(pool: &AnyPool, rel: Relation, alias_count: &mut u32) -> Query {
+fn sql_impl(tr: TransactionStatic, rel: Relation, alias_count: &mut u32) -> Query {
     let limit_str = rel
         .limit
         .map(|x| format!("LIMIT {}", x))
         .unwrap_or_else(String::new);
     match rel.inner {
         Inner::BackingStore(ty, policies) => {
-            sql_backing_store(pool, rel.columns, &limit_str, ty, policies)
+            sql_backing_store(tr, rel.columns, &limit_str, ty, policies)
         }
         Inner::Filter(inner, restrictions) => sql_filter(
-            pool,
+            tr,
             rel.columns,
             &limit_str,
             alias_count,
             *inner,
             restrictions,
         ),
         Inner::Join(left, right) => {
-            sql_join(pool, &rel.columns, &limit_str, alias_count, *left, *right)
+            sql_join(tr, &rel.columns, &limit_str, alias_count, *left, *right)
         }
     }
 }
 
-pub(crate) fn sql(pool: &AnyPool, rel: Relation) -> SqlStream {
+pub(crate) fn sql(tr: TransactionStatic, rel: Relation) -> SqlStream {
     let mut v = 0;
     let columns = rel.columns.clone();
-    match sql_impl(pool, rel, &mut v) {
-        Query::Sql(s) => to_stream(pool, s, columns),
+    match sql_impl(tr.clone(), rel, &mut v) {
+        Query::Sql(s) => to_stream(tr, s, columns),
         Query::Stream(s) => s,
     }
 }