fix(client): parse Presto JSON response with custom reviver and BigInts

.nvmrc

@@ -1 +1 @@
-18.17.1
+21.0.0

apps/nest-server/src/app/app.service.ts

@@ -48,7 +48,14 @@ export class AppService {
       const results = await client.query(
         `select returnflag, linestatus, sum(quantity) as sum_qty, sum(extendedprice) as sum_base_price, sum(extendedprice * (1 - discount)) as sum_disc_price, sum(extendedprice * (1 - discount) * (1 + tax)) as sum_charge, avg(quantity) as avg_qty, avg(extendedprice) as avg_price, avg(discount) as avg_disc, count(*) as count_order from lineitem where shipdate <= date '1998-12-01' group by returnflag, linestatus order by returnflag, linestatus`,
       )
-      return { columns: results.columns, rows: results.data }
+      return {
+        columns: results.columns,
+        rows: JSON.stringify(results.data, (key, value) => {
+          if (typeof value !== 'bigint') return value
+
+          return value.toString()
+        }),
+      }
     } catch (error) {
       return (error as PrestoError).message
     }

presto-client/src/client.ts

@@ -8,6 +8,7 @@ import {
   QueryInfo,
   Table,
 } from './types'
+import { parseWithBigInts } from './utils'
 
 export class PrestoClient {
   private baseUrl: string
@@ -270,7 +271,7 @@ export class PrestoClient {
         throw new Error(`Query failed: ${JSON.stringify(await response.text())}`)
       }
 
-      const prestoResponse = (await response.json()) as PrestoResponse
+      const prestoResponse = (await this.prestoConversionToJSON({ response })) as PrestoResponse
       if (!prestoResponse) {
         throw new Error(`Query failed with an empty response from the server.`)
       }
@@ -334,6 +335,13 @@ export class PrestoClient {
       method,
     })
   }
+
+  private async prestoConversionToJSON({ response }: { response: Response }): Promise<unknown> {
+    const text = await response.text()
+    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+    // @ts-ignore JSON.parse with a 3 argument reviver is a stage 3 proposal with some support, allow it here.
+    return JSON.parse(text, parseWithBigInts)
+  }
 }
 
 export default PrestoClient

presto-client/src/utils.ts

@@ -0,0 +1,29 @@
+/**
+ * Parses a JSON including bigger numbers into BigInts
+ * This function checks if JSON.parse reviver callback has a context parameter
+ * and falls back onto the default parsing if not.
+ * See also:
+ * - https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse#browser_compatibility
+ * - https://github.com/tc39/proposal-json-parse-with-source
+ * @param _ Key
+ * @param value Parsed value
+ * @param context Context with source text
+ * @returns Parsed object with BigInts where required
+ */
+export function parseWithBigInts(_: string, value: unknown, context: { source: string }) {
+  if (!context) return value // Context is not available, fallback to default parse
+  const { source } = context
+  if (!source) return value // Source is not available, fallback to default parse
+
+  // Ignore non-numbers
+  if (typeof value !== 'number') return value
+
+  // If not an integer, use the value
+  // TODO: Check if Presto can return floats that could also lose precision
+  if (!Number.isInteger(value)) return value
+
+  // If number is a safe integer, we can use it
+  if (Number.isSafeInteger(value)) return value
+
+  return BigInt(source)
+}