support isolation level (#24)

* support isolation level * update * add test
tidbcloud · Oct 18, 2023 · df70faf · df70faf
1 parent 7c3b2d6
commit df70faf
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Showing 4 changed files with 45 additions and 15 deletions.
diff --git a/integration-test/basic.test.ts b/integration-test/basic.test.ts
@@ -126,5 +126,17 @@ describe('basic', () => {
     const row = r[0] as Record<string, any>
     expect(row.first_name).toEqual('base')
   })
+
+  test('transaction isolation level', async () => {
+    const con = connect({url: databaseURL, database: database, fetch})
+    await con.execute(`delete from ${table} where emp_no = 1`)
+
+    const tx = await con.begin({isolation:"READ COMMITTED"})
+    const result1 = await tx.execute(`select * from ${table}`) as Row[]
+    await con.execute(`insert into ${table} values (1, '\\"John\\"', 'Doe')`)
+    const result2 =  await tx.execute(`select * from ${table}`) as Row[]
+    await tx.commit()
+    expect(result1.length+1).toEqual(result2.length)
+  })
 })
 
diff --git a/src/config.ts b/src/config.ts
@@ -30,4 +30,8 @@ export interface ExecuteOptions {
   fullResult?: boolean
 }
 
+export interface TxOptions {
+  isolation?: 'READ COMMITTED' | 'REPEATABLE READ'
+}
+
 export type ExecuteArgs = object | any[] | null
diff --git a/src/index.ts b/src/index.ts
@@ -1,7 +1,7 @@
 import { format } from './format.js'
 import { cast } from './decode.js'
 import { DatabaseError } from './error.js'
-import { Config, ExecuteOptions, ExecuteArgs } from './config.js'
+import { Config, ExecuteOptions, ExecuteArgs, TxOptions } from './config.js'
 import { postQuery } from './serverless.js'
 
 export { Config, ExecuteOptions, ExecuteArgs, DatabaseError }
@@ -45,8 +45,13 @@ export class Tx {
     this.conn = conn
   }
 
-  async execute(query: string, args: ExecuteArgs = null, options: ExecuteOptions = defaultExecuteOptions): Promise<FullResult | Row[]> {
-    return this.conn.execute(query, args, options)
+  async execute(
+    query: string,
+    args: ExecuteArgs = null,
+    options: ExecuteOptions = defaultExecuteOptions,
+    txOptions: TxOptions = {}
+  ): Promise<FullResult | Row[]> {
+    return this.conn.execute(query, args, options, txOptions)
   }
 
   async commit(): Promise<FullResult | Row[]> {
@@ -87,17 +92,22 @@ export class Connection {
     }
   }
 
-  async begin(): Promise<Tx> {
+  async begin(txOptions: TxOptions = {}): Promise<Tx> {
     const conn = new Connection(this.config)
     const tx = new Tx(conn)
-    await tx.execute('BEGIN')
+    await tx.execute('BEGIN', undefined, undefined, txOptions)
     return tx
   }
 
-  async execute(query: string, args: ExecuteArgs = null, options: ExecuteOptions = defaultExecuteOptions): Promise<FullResult | Row[]> {
+  async execute(
+    query: string,
+    args: ExecuteArgs = null,
+    options: ExecuteOptions = defaultExecuteOptions,
+    txOptions: TxOptions = {}
+  ): Promise<FullResult | Row[]> {
     const sql = args ? format(query, args) : query
     const body = JSON.stringify({ query: sql })
-    const resp = await postQuery<QueryExecuteResponse>(this.config, body, this.session ?? '')
+    const resp = await postQuery<QueryExecuteResponse>(this.config, body, this.session ?? '', sql == 'BEGIN' ? txOptions.isolation : null)
 
     this.session = resp?.session ?? null
     if (this.session === null || this.session === '') {

diff --git a/src/serverless.ts b/src/serverless.ts
@@ -1,7 +1,7 @@
 import { Config } from './config.js'
 import { DatabaseError } from './error.js'
 import { Version } from './version.js'
-export async function postQuery<T>(config: Config, body, session = ''): Promise<T> {
+export async function postQuery<T>(config: Config, body, session = '', isolationLevel = null): Promise<T> {
   let fetchCacheOption: Record<string, any> = { cache: 'no-store' }
   // Cloudflare Workers does not support cache now https://github.com/cloudflare/workerd/issues/69
   try {
@@ -14,16 +14,20 @@ export async function postQuery<T>(config: Config, body, session = ''): Promise<
   const auth = btoa(`${config.username}:${config.password}`)
   const { fetch } = config
   const database = config.database ?? ''
+  const headers = {
+    'Content-Type': 'application/json',
+    'User-Agent': `serverless-js/${Version}`,
+    Authorization: `Basic ${auth}`,
+    'TiDB-Database': database,
+    'TiDB-Session': session
+  }
+  if (isolationLevel) {
+    headers['TiDB-Isolation-Level'] = isolationLevel
+  }
   const response = await fetch(url.toString(), {
     method: 'POST',
     body: body,
-    headers: {
-      'Content-Type': 'application/json',
-      'User-Agent': `serverless-js/${Version}`,
-      Authorization: `Basic ${auth}`,
-      'TiDB-Database': database,
-      'TiDB-Session': session
-    },
+    headers,
     ...fetchCacheOption
   })