Apply suggestion from @jaydeluca

jackshirazi · jaydeluca · web-flow · commit d220b099c7a7 · 2026-05-07T14:36:31.000+01:00
Although strictly speaking not a bug to have empty source mappings, it seems silly and most likely an error so agree it's good to catch it

Co-authored-by: Jay DeLuca &lt;jaydeluca4@gmail.com&gt;
diff --git a/dynamic-control/src/main/java/io/opentelemetry/contrib/dynamic/policy/registry/PolicyInitConfig.java b/dynamic-control/src/main/java/io/opentelemetry/contrib/dynamic/policy/registry/PolicyInitConfig.java
@@ -198,7 +198,7 @@ private static PolicySourceConfig parseDeclarativeSource(
 
     List<DeclarativeConfigProperties> mappingConfigs =
         sourceConfig.getStructuredList(MAPPINGS_DECLARATIVE_KEY);
-    if (mappingConfigs == null) {
+    if (mappingConfigs == null || mappingConfigs.isEmpty()) {
       throw new IllegalArgumentException("Each source must define a 'mappings' array.");
     }
     List<PolicySourceMappingConfig> mappings = new ArrayList<>();

Original file line number	Diff line number	Diff line change
`@@ -198,7 +198,7 @@ private static PolicySourceConfig parseDeclarativeSource(`
`198`	`198`
`199`	`199`	`List<DeclarativeConfigProperties> mappingConfigs =`
`200`	`200`	`sourceConfig.getStructuredList(MAPPINGS_DECLARATIVE_KEY);`
`201`		`- if (mappingConfigs == null) {`
	`201`	`+ if (mappingConfigs == null \|\| mappingConfigs.isEmpty()) {`
`202`	`202`	`throw new IllegalArgumentException("Each source must define a 'mappings' array.");`
`203`	`203`	`}`
`204`	`204`	`List<PolicySourceMappingConfig> mappings = new ArrayList<>();`