Add raw() method - fixes porsager#194 (porsager#196)

porsager · web-flow · commit 8b405b37fa9e · 2021-08-12T23:00:28.000+02:00
* Add raw() method - fixes porsager#194
diff --git a/README.md b/README.md
@@ -126,7 +126,7 @@ const sql = postgres()
 
 ## Query ```sql` ` -> Promise```
 
-A query will always return a `Promise` which resolves to a results array `[...]{ count, command }`. Destructuring is great to immediately access the first element.
+A query will always return a `Promise` which resolves to a results array `[...]{ count, command, columns }`. Destructuring is great to immediately access the first element.
 
 ```js
 
@@ -278,6 +278,12 @@ await sql`
 
 ```
 
+## Raw ```sql``.raw()```
+
+Using `.raw()` will return rows as an array with `Buffer` values for each column, instead of objects.
+
+This can be useful to receive identical named columns, or for specific performance / transformation reasons. The column definitions are still included on the result array with access to parsers for each column.
+
 ## Listen and notify
 
 When you call listen, a dedicated connection will automatically be made to ensure that you receive notifications in real time. This connection will be used for any further calls to listen. Listen returns a promise which resolves once the `LISTEN` query to Postgres completes, or if there is already a listener active.
diff --git a/lib/backend.js b/lib/backend.js
@@ -100,21 +100,25 @@ function Backend({
     let column
     let value
 
-    const row = {}
+    const row = backend.query.raw ? new Array(backend.query.statement.columns.length) : {}
     for (let i = 0; i < backend.query.statement.columns.length; i++) {
       column = backend.query.statement.columns[i]
       length = x.readInt32BE(index)
       index += 4
 
       value = length === -1
         ? null
-        : column.parser === undefined
-          ? x.toString('utf8', index, index += length)
-          : column.parser.array === true
-            ? column.parser(x.toString('utf8', index + 1, index += length))
-            : column.parser(x.toString('utf8', index, index += length))
-
-      row[column.name] = transform.value ? transform.value(value) : value
+        : backend.query.raw
+          ? x.slice(index, index += length)
+          : column.parser === undefined
+            ? x.toString('utf8', index, index += length)
+            : column.parser.array === true
+              ? column.parser(x.toString('utf8', index + 1, index += length))
+              : column.parser(x.toString('utf8', index, index += length))
+
+      backend.query.raw
+        ? (row[i] = value)
+        : (row[column.name] = transform.value ? transform.value(value) : value)
     }
 
     backend.query.stream
diff --git a/lib/index.js b/lib/index.js
@@ -67,7 +67,7 @@ function Postgres(a, b) {
     , listener
 
   function postgres(xs) {
-    return query({ prepare: options.prepare }, getConnection(), xs, Array.from(arguments).slice(1))
+    return query({ tagged: true, prepare: options.prepare }, getConnection(), xs, Array.from(arguments).slice(1))
   }
 
   Object.assign(postgres, {
@@ -124,7 +124,7 @@ function Postgres(a, b) {
       }, connection)
     })
 
-    query({ raw: true }, connection, begin || savepoint)
+    query({}, connection, begin || savepoint)
       .then(() => {
         const result = fn(scoped)
         return Array.isArray(result)
@@ -137,7 +137,7 @@ function Postgres(a, b) {
           : resolve(x)
       )
       .catch((err) => {
-        query({ raw: true }, connection,
+        query({}, connection,
           begin
             ? 'rollback'
             : 'rollback to ' + savepoint
@@ -150,7 +150,7 @@ function Postgres(a, b) {
       }))
 
     function scoped(xs) {
-      return query({}, connection, xs, Array.from(arguments).slice(1))
+      return query({ tagged: true }, connection, xs, Array.from(arguments).slice(1))
     }
   }
 
@@ -168,7 +168,7 @@ function Postgres(a, b) {
   function query(query, connection, xs, args) {
     query.origin = options.debug ? new Error().stack : cachedError(xs)
     query.prepare = 'prepare' in query ? query.prepare : options.prepare
-    if (!query.raw && (!Array.isArray(xs) || !Array.isArray(xs.raw)))
+    if (query.tagged && (!Array.isArray(xs) || !Array.isArray(xs.raw)))
       return nested(xs, args)
 
     const promise = new Promise((resolve, reject) => {
@@ -206,7 +206,7 @@ function Postgres(a, b) {
 
   function send(connection, query, xs, args) {
     connection
-      ? process.nextTick(connection.send, query, query.raw ? parseRaw(query, xs, args) : parse(query, xs, args))
+      ? process.nextTick(connection.send, query, query.tagged ? parseTagged(query, xs, args) : parseUnsafe(query, xs, args))
       : queries.push({ query, xs, args })
   }
 
@@ -241,7 +241,7 @@ function Postgres(a, b) {
   function fetchArrayTypes(connection) {
     return arrayTypesPromise || (arrayTypesPromise =
       new Promise((resolve, reject) => {
-        send(connection, { resolve, reject, raw: true, prepare: false, origin: new Error().stack }, `
+        send(connection, { resolve, reject, tagged: false, prepare: false, origin: new Error().stack }, `
           select b.oid, b.typarray
           from pg_catalog.pg_type a
           left join pg_catalog.pg_type b on b.oid = a.typelem
@@ -286,7 +286,7 @@ function Postgres(a, b) {
 
     function unsafe(xs, args, queryOptions) {
       const prepare = queryOptions && queryOptions.prepare || false
-      return query({ raw: true, simple: !args, prepare }, connection || getConnection(), xs, args || [])
+      return query({ simple: !args, prepare }, connection || getConnection(), xs, args || [])
     }
 
     function file(path, args, options = {}) {
@@ -299,7 +299,7 @@ function Postgres(a, b) {
         options.cache = true
 
       const file = files[path]
-      const q = { raw: true, simple: !args }
+      const q = { tagged: false, simple: !args }
 
       if (options.cache && typeof file === 'string')
         return query(q, connection || getConnection(), file, args || [])
@@ -325,6 +325,7 @@ function Postgres(a, b) {
   }
 
   function addMethods(promise, query) {
+    promise.raw = () => (query.raw = true, promise)
     promise.stream = (fn) => (query.stream = fn, promise)
     promise.cursor = (rows, fn) => {
       if (typeof rows === 'function') {
@@ -350,7 +351,7 @@ function Postgres(a, b) {
 
     listeners[channel] = [fn]
 
-    return query({ raw: true }, listener.conn, 'listen ' + escape(channel))
+    return query({}, listener.conn, 'listen ' + escape(channel))
       .then((result) => {
         Object.assign(listener.result, result)
         return Object.create(listener.result, {
@@ -368,7 +369,7 @@ function Postgres(a, b) {
         return Promise.resolve()
 
       delete listeners[channel]
-      return query({ raw: true }, getListener().conn, 'unlisten ' + escape(channel)).then(() => undefined)
+      return query({}, getListener().conn, 'unlisten ' + escape(channel)).then(() => undefined)
     }
   }
 
@@ -409,7 +410,7 @@ function Postgres(a, b) {
     .then(() => clearTimeout(destroy))
   }
 
-  function parseRaw(query, str, args = []) {
+  function parseUnsafe(query, str, args = []) {
     const types = []
         , xargs = []
 
@@ -422,7 +423,7 @@ function Postgres(a, b) {
     }
   }
 
-  function parse(query, xs, args = []) {
+  function parseTagged(query, xs, args = []) {
     const xargs = []
         , types = []
 
diff --git a/tests/index.js b/tests/index.js
@@ -1321,3 +1321,19 @@ t('Escaping supports schemas and tables', async() => {
     await sql`drop schema a`
   ]
 })
+
+t('Raw method returns rows as arrays', async() => {
+  const [x] = await sql`select 1`.raw()
+  return [
+    Array.isArray(x),
+    true
+  ]
+})
+
+t('Raw method returns values unparsed as Buffer', async() => {
+  const [[x]] = await sql`select 1`.raw()
+  return [
+    x instanceof Buffer,
+    true
+  ]
+})
