feat: skip instrumentation of HANA driver, if it does it itself (#305)

Author: sjvans

CHANGELOG.md

@@ -8,6 +8,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/).
 
 ### Added
 
+- Skip instrumentation of HANA driver, if it does it itself
+
 ### Changed
 
 - By default, `@cap-js/hana`'s promisification of the driver API is wrapped

lib/tracing/cds.js

@@ -82,12 +82,17 @@ module.exports = () => {
   if (impl?.match(/^@cap-js\//)) {
     cds.once('served', () => {
       // HANA
-      if (impl === '@cap-js/hana' && cds.env.requires.telemetry.tracing._hana_prom) {
+      if (impl === '@cap-js/hana') {
         try {
+          // REVISIT: when telemetry and hana are loaded from different places this doesn't work
+          const hanaDriver = require('@cap-js/hana/lib/drivers/base.js')
+
+          // driver does instrumentation itself?
+          if (hanaDriver.isOpenTelemetrySupported) return
+
+          // wrap promisified HANA driver
           const [major, minor] = require('@cap-js/hana/package.json').version.split('.')
-          if (major > 1 || (major === 1 && minor >= 7)) {
-            // REVISIT: when telemetry and hana are loaded from differen places this doesn't work
-            const hanaDriver = require('@cap-js/hana/lib/drivers/base.js')
+          if (cds.env.requires.telemetry.tracing._hana_prom && (major > 1 || (major === 1 && minor >= 7))) {
             const _prom = hanaDriver.prom
             hanaDriver.prom = function (dbc, func) {
               const fn = _prom(dbc, func)
@@ -100,11 +105,11 @@ module.exports = () => {
             return
           }
         } catch (err) {
-          LOG._warning && LOG.warning('Failed to wrap hana driver due to error:', err)
+          LOG._warn && LOG.warn('Failed to wrap hana driver due to error:', err)
         }
       }
 
-      // other DBs
+      // other DBs (or non-promisified HANA driver)
       const dbService = cds.db.constructor
       const { prepare: _prepare, exec: _exec } = dbService.prototype
       dbService.prototype.prepare = wrap(_prepare, {