From 2f9d25f6f81f43c2ae4543fea56de12a6429084c Mon Sep 17 00:00:00 2001
From: Benedek Izso <benedek.izso@emarsys.com>
Date: Wed, 8 Oct 2025 11:44:25 +0200
Subject: [PATCH] feat(logger): add error cause logging DIME-8714

Co-authored-by: Balint Barki <balint.barki@sap.com>
---
 src/logger/logger.spec.ts | 32 ++++++++++++++++++++++++++++++++
 src/logger/logger.ts      | 18 ++++++++++++------
 2 files changed, 44 insertions(+), 6 deletions(-)

diff --git a/src/logger/logger.spec.ts b/src/logger/logger.spec.ts
index 952c582..0990bee 100644
--- a/src/logger/logger.spec.ts
+++ b/src/logger/logger.spec.ts
@@ -250,6 +250,38 @@ describe('Logger', () => {
     expect(logArguments.http.response.body.content).to.eql(JSON.stringify(error.response?.data));
   });
 
+  it('should log causes', () => {
+    const rootCause = new Error('Root cause error');
+    rootCause.name = 'RootCauseError';
+    rootCause.stack = 'RootCauseError: Root cause error\n    at rootFunction()';
+
+    const intermediateError = new Error('Intermediate error');
+    intermediateError.name = 'IntermediateError';
+    intermediateError.stack = 'IntermediateError: Intermediate error\n    at intermediateFunction()';
+    intermediateError.cause = rootCause;
+
+    const mainError = new Error('Main error occurred');
+    mainError.name = 'MainError';
+    mainError.stack = 'MainError: Main error occurred\n    at mainFunction()';
+    mainError.cause = intermediateError;
+
+    logger.fromError('test_action', mainError, { details: 'test details' });
+
+    const logArguments = JSON.parse(outputStub.args[0][0]);
+    expect(logArguments.error.type).to.eql('MainError');
+    expect(logArguments.error.message).to.eql('Main error occurred');
+    expect(logArguments.error.cause).to.eql({
+      type: 'IntermediateError',
+      message: 'Intermediate error',
+      stack_trace: intermediateError.stack,
+      cause: {
+        type: 'RootCauseError',
+        message: 'Root cause error',
+        stack_trace: rootCause.stack,
+      },
+    });
+  });
+
   describe('#customError', () => {
     it('should log error as the given severity with action', () => {
       const error: Error & { data?: any } = new Error('failed');
diff --git a/src/logger/logger.ts b/src/logger/logger.ts
index 9420da2..31d33c5 100644
--- a/src/logger/logger.ts
+++ b/src/logger/logger.ts
@@ -181,18 +181,24 @@ export class Logger {
     }
 
     return {
-      error: {
-        type: error.name,
-        message: error.message,
-        context: this.shortenData((error as ErrorWithData).data),
-        stack_trace: this.shortenStackTrace(error.stack || ''),
-      },
+      error: this.extractError(error),
       event: {
         reason: error.message,
       },
     };
   }
 
+  private extractError(error: Error): unknown {
+    const shortenedData = this.shortenData((error as ErrorWithData).data);
+    return {
+      type: error.name,
+      message: error.message,
+      ...(shortenedData && { context: shortenedData }),
+      stack_trace: this.shortenStackTrace(error.stack || ''),
+      ...(error.cause instanceof Error && { cause: this.extractError(error.cause) }),
+    };
+  }
+
   private getAxiosErrorDetails(error: AxiosError) {
     if (!error.isAxiosError) {
       return {};