feat(logging): set level via env var (#4340)

* feat(logging): set level via env var

* add tests

* add changeset

* fix test

* Update .changeset/ten-timers-sneeze.md

---------

Co-authored-by: Deeksha Sinha <88374536+deekshas8@users.noreply.github.com>
Co-authored-by: deekshas8 <deeksha.sinha@sap.com>
Co-authored-by: Marika Marszalkowski <868536+marikaner@users.noreply.github.com>

.changeset/ten-timers-sneeze.md

@@ -0,0 +1,5 @@
+---
+'@sap-cloud-sdk/util': minor
+---
+
+[New Functionality] Add support for setting log level for newly created logger using environment variable `SAP_CLOUD_SDK_LOG_LEVEL`.

packages/util/src/logger/cloud-sdk-logger.spec.ts

@@ -48,9 +48,25 @@ describe('Cloud SDK Logger', () => {
       delete process.env.VCAP_SERVICES;
     });
 
-    it('creates a new default logger', () => {
+    it('creates a new default logger with default log level info', () => {
       logger = createLogger();
       expect(logger).not.toBeUndefined();
+      expect(logger.level).toEqual('info');
+    });
+
+    it('creates logger with log level from env variable, if one is specified', () => {
+      process.env.SAP_CLOUD_SDK_LOG_LEVEL = 'silly';
+
+      logger = createLogger();
+      expect(logger).not.toBeUndefined();
+      expect(logger.level).toEqual('silly');
+
+      const write = spyOnWrite(logger);
+
+      logger.silly(message);
+
+      expect(write).toHaveBeenCalled();
+      delete process.env.SAP_CLOUD_SDK_LOG_LEVEL;
     });
 
     it('creates a new logger for a module', () => {

packages/util/src/logger/cloud-sdk-logger.ts

@@ -116,6 +116,7 @@ export function createLogger(
       : { ...messageContext };
   const logger = container.get(customFields.messageContext, {
     level:
+      process.env.SAP_CLOUD_SDK_LOG_LEVEL ||
       customLogLevels[customFields.messageContext] ||
       customFields.level ||
       container.options.level ||