fix: treat empty operation name the same as null

RafeArnold · RafeArnold · commit cca6387f28ca · 2026-04-23T15:47:27.000+01:00
previously, if an empty operation name was given and multiple
operations were provided in the query, then the first operation would be
 returned, rather than complaining that no operation name was provided.
diff --git a/src/main/java/graphql/language/NodeUtil.java b/src/main/java/graphql/language/NodeUtil.java
@@ -73,12 +73,13 @@ public static GetOperationResult getOperation(Document document, String operatio
                 fragmentsByName.put(fragmentDefinition.getName(), fragmentDefinition);
             }
         }
-        if (operationName == null && operationsByName.size() > 1) {
+        boolean operationNameProvided = operationName != null && !operationName.isEmpty();
+        if (!operationNameProvided && operationsByName.size() > 1) {
             throw new UnknownOperationException("Must provide operation name if query contains multiple operations.");
         }
         OperationDefinition operation;
 
-        if (operationName == null || operationName.isEmpty()) {
+        if (!operationNameProvided) {
             operation = operationsByName.values().iterator().next();
         } else {
             operation = operationsByName.get(operationName);
diff --git a/src/test/groovy/graphql/language/NodeUtilTest.groovy b/src/test/groovy/graphql/language/NodeUtilTest.groovy
@@ -15,11 +15,14 @@ class NodeUtilTest extends Specification {
         ''')
 
         when:
-        NodeUtil.getOperation(doc, null)
+        NodeUtil.getOperation(doc, operationName)
 
         then:
         def ex = thrown(UnknownOperationException)
         ex.message == "Must provide operation name if query contains multiple operations."
+
+        where:
+        operationName << [null, '']
     }
 
     def "getOperation: when multiple operations are defined in the query and operation name doesn't match any of the query operations then it should throw UnknownOperationException"() {

Original file line number	Diff line number	Diff line change
`@@ -73,12 +73,13 @@ public static GetOperationResult getOperation(Document document, String operatio`
`73`	`73`	`fragmentsByName.put(fragmentDefinition.getName(), fragmentDefinition);`
`74`	`74`	`}`
`75`	`75`	`}`
`76`		`- if (operationName == null && operationsByName.size() > 1) {`
	`76`	`+ boolean operationNameProvided = operationName != null && !operationName.isEmpty();`
	`77`	`+ if (!operationNameProvided && operationsByName.size() > 1) {`
`77`	`78`	`throw new UnknownOperationException("Must provide operation name if query contains multiple operations.");`
`78`	`79`	`}`
`79`	`80`	`OperationDefinition operation;`
`80`	`81`
`81`		`- if (operationName == null \|\| operationName.isEmpty()) {`
	`82`	`+ if (!operationNameProvided) {`
`82`	`83`	`operation = operationsByName.values().iterator().next();`
`83`	`84`	`} else {`
`84`	`85`	`operation = operationsByName.get(operationName);`