feat: SELECT returns binaries as Buffers

sqlite/lib/SQLiteService.js

@@ -5,6 +5,11 @@ const $session = Symbol('dbc.session')
 const convStrm = require('stream/consumers')
 const { Readable } = require('stream')
 
+const BINARY_TYPES = {
+  'cds.Binary': 1,
+  'cds.hana.BINARY': 1
+}
+
 class SQLiteService extends SQLService {
   init() {
     return super.init(...arguments)
@@ -137,6 +142,38 @@ class SQLiteService extends SQLService {
     return (await ps.run(vals)).changes
   }
 
+  // change each binary to Buffer except of large binaries
+  _changeToBuffers(columns, rows, one, compat) {
+    if (!rows || !columns) return
+    if (!Array.isArray(rows)) rows = [rows]
+    if (!rows.length || !Object.keys(rows[0]).length) return
+    if (compat) return
+
+    for (let col of columns) {
+      const name = col.as || col.ref?.[col.ref.length - 1] || (typeof col === 'string' && col)
+      if (col.element?.isAssociation) {
+        if (one) this._changeToBuffers(col.SELECT.columns, rows[0][name], false, compat)
+        else
+          rows.forEach(row => {
+            this._changeToBuffers(col.SELECT.columns, row[name], false, compat)
+          })
+      } else if (col.element?.type in BINARY_TYPES) {
+        if (one) rows[0][name] = Buffer.from(rows[0][name], 'base64')
+        else
+          rows.forEach(row => {
+            row[name] = Buffer.from(row[name], 'base64')
+          })
+      }
+    }
+  }
+
+  async onSELECT(req) {
+    const rows = await super.onSELECT(req)
+    this._changeToBuffers(req.query.SELECT.columns, rows, req.query.SELECT.one, cds.env.features.stream_compat)
+
+    return rows
+  }
+
   onPlainSQL({ query, data }, next) {
     if (typeof query === 'string') {
       // REVISIT: this is a hack the target of $now might not be a timestamp or date time