Better support for NULLs

__tests__/index.test.ts

@@ -121,18 +121,21 @@ describe('execute', () => {
     const mockResponse = {
       session: mockSession,
       result: {
-        fields: [{ name: ':vtg1', type: 'INT32' }],
-        rows: [{ lengths: ['1'], values: 'MQ==' }]
+        fields: [{ name: ':vtg1', type: 'INT32' }, { name: 'null' }],
+        rows: [{ lengths: ['1', '-1'], values: 'MQ==' }]
       }
     }
 
     const want: ExecutedQuery = {
-      headers: [':vtg1'],
-      types: { ':vtg1': 'INT32' },
-      fields: [{ name: ':vtg1', type: 'INT32' }],
-      rows: [{ ':vtg1': 1 }],
+      headers: [':vtg1', 'null'],
+      types: { ':vtg1': 'INT32', null: 'NULL' },
+      fields: [
+        { name: ':vtg1', type: 'INT32' },
+        { name: 'null', type: 'NULL' }
+      ],
+      rows: [{ ':vtg1': 1, null: null }],
       size: 1,
-      statement: 'SELECT 1 from dual;',
+      statement: 'SELECT 1, null from dual;',
       time: 1,
       rowsAffected: null,
       insertId: null
@@ -146,7 +149,54 @@ describe('execute', () => {
     })
 
     const connection = connect(config)
-    const got = await connection.execute('SELECT 1 from dual;')
+    const got = await connection.execute('SELECT 1, null from dual;')
+    got.time = 1
+
+    expect(got).toEqual(want)
+
+    mockPool.intercept({ path: EXECUTE_PATH, method: 'POST' }).reply(200, (opts) => {
+      expect(opts.headers['authorization']).toMatch(/Basic /)
+      const bodyObj = JSON.parse(opts.body.toString())
+      expect(bodyObj.session).toEqual(mockSession)
+      return mockResponse
+    })
+
+    const got2 = await connection.execute('SELECT 1, null from dual;')
+    got2.time = 1
+
+    expect(got2).toEqual(want)
+  })
+
+  test('it properly returns and decodes a select query (select null)', async () => {
+    const mockResponse = {
+      session: mockSession,
+      result: {
+        fields: [{ name: 'null' }],
+        rows: [{ lengths: ['-1'] }]
+      }
+    }
+
+    const want: ExecutedQuery = {
+      headers: ['null'],
+      types: { null: 'NULL' },
+      fields: [{ name: 'null', type: 'NULL' }],
+      rows: [{ null: null }],
+      size: 1,
+      statement: 'SELECT null',
+      time: 1,
+      rowsAffected: null,
+      insertId: null
+    }
+
+    mockPool.intercept({ path: EXECUTE_PATH, method: 'POST' }).reply(200, (opts) => {
+      expect(opts.headers['authorization']).toMatch(/Basic /)
+      const bodyObj = JSON.parse(opts.body.toString())
+      expect(bodyObj.session).toEqual(null)
+      return mockResponse
+    })
+
+    const connection = connect(config)
+    const got = await connection.execute('SELECT null')
     got.time = 1
 
     expect(got).toEqual(want)
@@ -158,7 +208,7 @@ describe('execute', () => {
       return mockResponse
     })
 
-    const got2 = await connection.execute('SELECT 1 from dual;')
+    const got2 = await connection.execute('SELECT null')
     got2.time = 1
 
     expect(got2).toEqual(want)

src/index.ts

@@ -64,7 +64,7 @@ export interface Config {
 
 interface QueryResultRow {
   lengths: string[]
-  values: string
+  values?: string
 }
 
 export interface Field {
@@ -217,6 +217,15 @@ export class Connection {
     this.session = session
 
     const fields = result?.fields ?? []
+    // ensure each field has a type assigned,
+    // the only case it would be omitted is in the case of
+    // NULL due to the protojson spec. NULL in our enum
+    // is 0, and empty fields are omitted from the JSON response,
+    // so we should backfill an expected type.
+    for (const field of fields) {
+      field.type ||= 'NULL'
+    }
+
     const rows = result ? parse(result, this.config.cast || cast, options.as || 'object') : []
     const headers = fields.map((f) => f.name)
 
@@ -304,7 +313,7 @@ function parse(result: QueryResult, cast: Cast, returnAs: ExecuteAs): Row[] {
 }
 
 function decodeRow(row: QueryResultRow): Array<string | null> {
-  const values = atob(row.values)
+  const values = row.values ? atob(row.values) : ''
   let offset = 0
   return row.lengths.map((size) => {
     const width = parseInt(size, 10)