chore: added comment

Author: aryamohanan

packages/core/src/config/index.js

@@ -392,7 +392,15 @@ function normalizeTracingHttp({ userConfig = {}, defaultConfig = {}, finalConfig
 
   const userHeaders = userHttp?.extraHttpHeadersToCapture;
 
-  // 1. Check in-code configuration first
+  // 1. Check environment variable
+  if (process.env.INSTANA_EXTRA_HTTP_HEADERS) {
+    const fromEnvVar = parseHeadersEnvVar(process.env.INSTANA_EXTRA_HTTP_HEADERS);
+    finalConfig.tracing.http.extraHttpHeadersToCapture = fromEnvVar;
+    logger.debug(`[config] env:INSTANA_EXTRA_HTTP_HEADERS = ${process.env.INSTANA_EXTRA_HTTP_HEADERS}`);
+    return;
+  }
+
+  // 2. Check in-code configuration
   if (userHeaders !== undefined) {
     if (!Array.isArray(userHeaders)) {
       logger.warn(
@@ -408,14 +416,6 @@ function normalizeTracingHttp({ userConfig = {}, defaultConfig = {}, finalConfig
     }
   }
 
-  // 2. Check environment variable
-  if (process.env.INSTANA_EXTRA_HTTP_HEADERS) {
-    const fromEnvVar = parseHeadersEnvVar(process.env.INSTANA_EXTRA_HTTP_HEADERS);
-    finalConfig.tracing.http.extraHttpHeadersToCapture = fromEnvVar;
-    logger.debug(`[config] env:INSTANA_EXTRA_HTTP_HEADERS = ${process.env.INSTANA_EXTRA_HTTP_HEADERS}`);
-    return;
-  }
-
   // 3. Use default configuration
   finalConfig.tracing.http.extraHttpHeadersToCapture = defaultConfig.tracing.http.extraHttpHeadersToCapture;
 }
@@ -448,6 +448,7 @@ function normalizeTracingStackTrace({ userConfig = {}, defaultConfig = {}, final
   const envStackTrace = process.env.INSTANA_STACK_TRACE;
   const envStackTraceLength = process.env.INSTANA_STACK_TRACE_LENGTH;
 
+  // Priority 1: Environment variable
   if (envStackTrace !== undefined) {
     const result = validateStackTraceMode(envStackTrace);
 
@@ -463,6 +464,7 @@ function normalizeTracingStackTrace({ userConfig = {}, defaultConfig = {}, final
       finalConfig.tracing.stackTrace = defaultConfig.tracing.stackTrace;
     }
   } else if (userGlobal?.stackTrace !== undefined) {
+    // Priority 2: In-code configuration
     const result = validateStackTraceMode(userGlobal.stackTrace);
 
     if (result.isValid) {
@@ -483,6 +485,7 @@ function normalizeTracingStackTrace({ userConfig = {}, defaultConfig = {}, final
   const isLegacyLengthDefined = userTracingConfig?.stackTraceLength !== undefined;
   const stackTraceConfigValue = userGlobal?.stackTraceLength || userTracingConfig?.stackTraceLength;
 
+  // Priority 1: Environment variable
   if (envStackTraceLength !== undefined) {
     const result = validateStackTraceLength(envStackTraceLength);
 
@@ -498,6 +501,7 @@ function normalizeTracingStackTrace({ userConfig = {}, defaultConfig = {}, final
       finalConfig.tracing.stackTraceLength = defaultConfig.tracing.stackTraceLength;
     }
   } else if (stackTraceConfigValue !== undefined) {
+    // Priority 2: In-code configuration
     if (isLegacyLengthDefined) {
       logger.warn(
         // eslint-disable-next-line max-len