add optional isolation level config to transactions

Author: Felix Robles

src/cryptography/abstract/HMAC.ts

@@ -1,6 +1,6 @@
 import { Digest } from "./Digest"
 /**
- * A HMAC ( commonly referred to as a Hash ) (hash-based message authentication
+ * A HMAC (hash-based message authentication
  * code) is a type of message authentication code (MAC) that uses a
  * cryptographic hash function and a secret key. It may be used to verify data
  * integrity and authentication of a message.

src/cryptography/drivers/node/SHA1HMAC.ts

@@ -2,7 +2,7 @@ import { HMAC } from "../../abstract/HMAC"
 import { createHmac } from "crypto"
 
 /**
- * The SHA1HMAC provides a HMAC implementation using SHA1 based on Node's
+ * The SHA1HMAC class provides a HMAC implementation using SHA1 based on Node's
  * OpenSSL.
  *
  * This implementation relies on the node crypto implementation and may vary based

src/datastore/abstract/PGIsolationLevel.ts

@@ -0,0 +1,9 @@
+/**
+ * PostgreSQL transaction isolation levels
+ */
+export enum PGIsolationLevel {
+    SERIALIZABLE = "SERIALIZABLE",
+    REPEATABLE_READ = "REPEATABLE_READ",
+    READ_COMMITED = "READ_COMMITED",
+    READ_UNCOMMITED = "READ_UNCOMMITED",
+}

src/datastore/abstract/PGTransactionOptions.ts

@@ -0,0 +1,8 @@
+import { PGIsolationLevel } from "./PGIsolationLevel"
+
+/**
+ * Set characteristics of the PostgreSQL transaction
+ */
+export interface PGTransactionOptions {
+    isolation_level: PGIsolationLevel
+}

src/datastore/drivers/pg/PGStore.ts

@@ -1,4 +1,6 @@
+import { PGIsolationLevel } from "../../abstract/PGIsolationLevel"
 import { PGTransaction } from "./PGTransaction"
+import { PGTransactionOptions } from "../../abstract/PGTransactionOptions"
 import { SQLStore } from "../../abstract/SQLStore"
 import { Container } from "inversify"
 import { Logger } from "../../../logging"
@@ -34,15 +36,30 @@ export class PGStore implements Process, SQLStore {
         }
     }
 
-    public async createTransaction(): Promise<PGTransaction> {
+    public async createTransaction(
+        options?: Partial<PGTransactionOptions>
+    ): Promise<PGTransaction> {
         if (this.connection === undefined) {
             throw new Error(
                 "PGStore cannot open a transaction on a closed Pool. This usually happens from forgetting to call startup."
             )
         }
 
         let connection = await this.connection.connect()
-        await connection.query("BEGIN")
+        let query = "BEGIN"
+        if (options !== undefined && options.isolation_level !== undefined) {
+            switch (options.isolation_level) {
+                case PGIsolationLevel.SERIALIZABLE:
+                    query = "BEGIN TRANSACTION ISOLATION LEVEL SERIALIZABLE"
+                case PGIsolationLevel.REPEATABLE_READ:
+                    query = "BEGIN TRANSACTION ISOLATION LEVEL REPEATABLE_READ"
+                case PGIsolationLevel.READ_COMMITED:
+                    query = "BEGIN TRANSACTION ISOLATION LEVEL READ COMMITTED"
+                case PGIsolationLevel.READ_UNCOMMITED:
+                    query = "BEGIN TRANSACTION ISOLATION LEVEL READ UNCOMMITED"
+            }
+        }
+        await connection.query(query)
 
         return new PGTransaction(connection, this.logger)
     }

src/logging/abstract/LogLevel.ts

@@ -1,5 +1,5 @@
 /**
- * The standarzied levels used across all Logger integrations
+ * The standarized levels used across all Logger integrations
  */
 export enum LogLevel {
     /**