Add parametricDatetime option

To opt-in to datetime types with variable precision. Closes #32.

Ref trinodb/trino#1284

lib/client.js

@@ -36,6 +36,7 @@ module.exports = class Client extends EventEmitter {
     this.schema = opts.schema || null
     this.user = opts.user || null
     this.timezone = opts.timezone || null
+    this.parametricDatetime = opts.parametricDatetime || false
 
     this.pollInterval = msOption('pollInterval', opts.pollInterval || 1e3)
     this.socketTimeout = msOption('socketTimeout', opts.socketTimeout || 120e3)
@@ -58,11 +59,13 @@ module.exports = class Client extends EventEmitter {
     const schema = opts.schema || this.schema
     const timezone = opts.timezone || this.timezone
     const user = opts.user || this.user
+    const parametricDatetime = opts.parametricDatetime || this.parametricDatetime
 
     // TODO: these may not be necessary for GET /v1/statement/{queryId}/{token}
     if (catalog) headers['X-Presto-Catalog'] = catalog
     if (schema) headers['X-Presto-Schema'] = schema
     if (timezone) headers['X-Presto-Time-Zone'] = timezone
+    if (parametricDatetime) headers['X-Presto-Client-Capabilities'] = 'PARAMETRIC_DATETIME'
 
     if (user) headers['X-Presto-User'] = user
     if (opts.json) headers['Accept'] = 'application/json'

readme.md

@@ -87,6 +87,7 @@ Options:
 - `protocol`: string, one of `http:` (default) or `https:`
 - `user`: string, default none. Sent as `X-Presto-User` header.
 - `timezone`: string, for example `UTC`, default none. Sent as `X-Presto-Time-Zone` header.
+- `parametricDatetime`: boolean, default false. Opt-in to datetime types with variable precision, for example `timestamp(6)`. When not set, datetime types are returned with a precision of 3.
 
 You can specify a [catalog](https://prestosql.io/docs/current/overview/concepts.html#catalog) and [schema](https://prestosql.io/docs/current/overview/concepts.html#schema) to avoid writing fully-qualified table names in queries:
 

test/integration/index.js

@@ -9,7 +9,8 @@ const config = {
   port: 8080,
   user: 'test',
   schema: 'test',
-  catalog: 'memory'
+  catalog: 'memory',
+  timezone: 'UTC'
 }
 
 const factory = (opts) => lento({ ...config, ...opts })
@@ -40,3 +41,43 @@ test('basic', function (t) {
     })
   })
 })
+
+test('timestamp is returned with default precision of 3', function (t) {
+  t.plan(4)
+
+  const client = factory()
+  const table = 'timestamp_' + Date.now()
+
+  client.query(`CREATE TABLE ${table} (ts timestamp(6))`, (err) => {
+    t.ifError(err, 'no query error')
+
+    client.query(`INSERT INTO ${table} VALUES (timestamp '2020-09-05 10:01:48.123456')`, (err) => {
+      t.ifError(err, 'no query error')
+
+      client.query(`SELECT * FROM ${table}`, { deserialize: false }, (err, rows) => {
+        t.ifError(err, 'no query error')
+        t.same(rows, [{ ts: '2020-09-05 10:01:48.123' }])
+      })
+    })
+  })
+})
+
+test('enable PARAMETRIC_DATETIME capability', function (t) {
+  t.plan(4)
+
+  const client = factory({ parametricDatetime: true })
+  const table = 'parametric_datetime_' + Date.now()
+
+  client.query(`CREATE TABLE ${table} (ts timestamp(6))`, (err) => {
+    t.ifError(err, 'no query error')
+
+    client.query(`INSERT INTO ${table} VALUES (timestamp '2020-09-05 10:01:48.123456')`, (err) => {
+      t.ifError(err, 'no query error')
+
+      client.query(`SELECT * FROM ${table}`, { deserialize: false }, (err, rows) => {
+        t.ifError(err, 'no query error')
+        t.same(rows, [{ ts: '2020-09-05 10:01:48.123456' }])
+      })
+    })
+  })
+})