Added integration tests for transactions.

Added isolation levels to api.

spec/integration/sql/transaction-setup.sql

@@ -0,0 +1,4 @@
+DROP TABLE IF EXISTS dbo.MutationTests;
+CREATE TABLE dbo.MutationTests(
+	id int
+);

spec/integration/transaction.spec.js

@@ -0,0 +1,86 @@
+const { config } = testHelpers;
+
+const skwell = require( "src/" );
+describe( "Transaction - Integration", () => {
+	let sql;
+	before( () => {
+		sql = skwell.connect( config );
+		return sql.execute( sql.fromFile( "sql/transaction-setup.sql" ) );
+	} );
+
+	beforeEach( async () => {
+		await sql.execute( "DELETE FROM MutationTests" );
+	} );
+
+	after( () => {
+		return sql.dispose();
+	} );
+
+	describe( "isolation levels", () => {
+		const isolationLevelQuery = `
+			SELECT CASE transaction_isolation_level
+				WHEN 0 THEN 'Unspecified'
+				WHEN 1 THEN 'ReadUncommitted'
+				WHEN 2 THEN 'ReadCommitted'
+				WHEN 3 THEN 'Repeatable'
+				WHEN 4 THEN 'Serializable'
+				WHEN 5 THEN 'Snapshot' END AS level
+			FROM sys.dm_exec_sessions
+			where session_id = @@SPID`;
+
+		it( "should default to read committed isolation level", async () => {
+			await sql.transaction( async tx => {
+				return tx.queryValue( isolationLevelQuery );
+			} ).should.eventually.equal( "ReadCommitted" );
+		} );
+
+		it( "should set isolation level", async () => {
+			await sql.transaction( sql.read_uncommitted, async tx => {
+				return tx.queryValue( isolationLevelQuery );
+			} ).should.eventually.equal( "ReadUncommitted" );
+		} );
+	} );
+
+	describe( "rollback", () => {
+		it( "should roll back transaction when sql fails", async () => {
+			const expectedError = "Automatic Rollback. Failed Because: Invalid object name 'fake_table'.";
+
+			await sql.transaction( async tx => {
+				await tx.execute( "insert into MutationTests(id) values (1)" );
+				await tx.query( "select lol from fake_table" );
+			} ).should.eventually.be.rejectedWith( expectedError );
+
+			const vals = await sql.query( "select * from MutationTests" );
+			vals.length.should.equal( 0 );
+		} );
+
+		it( "should roll back transaction when an error is thrown", async () => {
+			await sql.transaction( async tx => {
+				await tx.execute( "insert into MutationTests(id) values (1)" );
+				throw new Error( "NOPE" );
+			} ).should.eventually.be.rejectedWith( "NOPE" );
+
+			const vals = await sql.query( "select * from MutationTests" );
+			vals.length.should.equal( 0 );
+		} );
+
+		it( "should roll back transaction when manually calling rollback", async () => {
+			await sql.transaction( async tx => {
+				await tx.execute( "insert into MutationTests(id) values (1)" );
+				await tx.rollback();
+			} ).should.eventually.be.rejectedWith( "Manual Rollback" );
+
+			const vals = await sql.query( "select * from MutationTests" );
+			vals.length.should.equal( 0 );
+		} );
+	} );
+
+	it( "should commit transaction when promise resolves", async () => {
+		await sql.transaction( async tx => {
+			await tx.execute( "insert into MutationTests(id) values (1)" );
+		} );
+
+		const vals = await sql.query( "select * from MutationTests" );
+		vals.should.deep.equal( [ { id: 1 } ] );
+	} );
+} );

src/api.js

@@ -1,4 +1,4 @@
-const Request = require( "tedious" ).Request;
+const { Request, ISOLATION_LEVEL } = require( "tedious" );
 const Readable = require( "readable-stream" ).Readable;
 
 const parameterBuilder = require( "./parameterBuilder" );
@@ -108,5 +108,11 @@ class Api {
 }
 
 Object.assign( Api.prototype, types );
+
+Object.keys( ISOLATION_LEVEL ).forEach( k => {
+	Api.prototype[ k.toLowerCase() ] = ISOLATION_LEVEL[ k ];
+} );
+
 Api.prototype.fromFile = fileLoader;
+
 module.exports = Api;

src/transaction.js

@@ -30,7 +30,6 @@ class Transaction extends Api {
 			// TODO: wrap err instead of mangling message
 			err.message = `Automatic Rollback. Failed Because: ${ err.message }`;
 			await tx.rollback( err );
-			throw err;
 		}
 	}
 
@@ -43,10 +42,6 @@ class Transaction extends Api {
 	}
 
 	async rollback( err ) {
-		if ( this[ _state ].rolledBack ) {
-			return;
-		}
-
 		await this[ _state ].connection.rollbackTransaction();
 		this[ _state ].rolledBack = true;
 		throw err;

src/types.js

@@ -1,4 +1,4 @@
-const { TYPES } = require( "tedious" );
+const { TYPES, ISOLATION_LEVEL } = require( "tedious" );
 
 const TypeWrapper = require( "./TypeWrapper" );