fix: treat empty operation name the same as null

RafeArnold · RafeArnold · commit d5cdc079dad1 · 2026-01-23T11:26:05.000Z
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);`