Relax generated Java path length limit

.chronus/changes/fix-java-relax-generated-path-length-2026-09-16.md

@@ -0,0 +1,7 @@
+---
+changeKind: fix
+packages:
+  - "@typespec/http-client-java"
+---
+
+Allow generated test and sample filenames to use the Azure SDK for Java pipeline's relaxed path-length limit.

packages/http-client-java/generator/http-client-generator-core/src/main/java/com/microsoft/typespec/http/client/generator/core/util/ClassNameUtil.java

@@ -8,6 +8,10 @@
 
 public final class ClassNameUtil {
 
+    static final int MAX_PATH_LENGTH = 260;
+    private static final int MAX_DIRECTORY_LENGTH = 248;
+    static final int BASE_PATH_LENGTH = 30;
+
     /**
      * Truncate class name to avoid path too long.
      *
@@ -24,8 +28,6 @@ public static String truncateClassName(String namespace, String directory, Strin
         String classNameSuffix) {
         // see
         // https://github.com/Azure/azure-sdk-for-java/blob/main/eng/common/pipelines/templates/steps/verify-path-length.yml
-        final int maxPathLength = 260;
-        final int basePathLength = 38;
 
         // directory layout in Java SDK repository is:
         // sdk/<group>/<artifact>/<directory>/<package_name>/<class_name><class_name_suffix>.java
@@ -43,7 +45,7 @@ public static String truncateClassName(String namespace, String directory, Strin
 
         final int minRemainLength = 5;  // we still need some char for class name
 
-        final int remainLength = maxPathLength - basePathLength - groupLength - artifactLength - directoryLength
+        final int remainLength = MAX_PATH_LENGTH - BASE_PATH_LENGTH - groupLength - artifactLength - directoryLength
             - packageLength - classNameSuffixLength - extraLength;
 
         if (remainLength < className.length() && remainLength >= minRemainLength) {
@@ -68,10 +70,10 @@ public static String getDirectoryNameForGraalVmConfig(String groupId, String art
             ? artifactIdSegments[2]
             : artifactIdSegments[artifactIdSegments.length - 1]);
         final int parentDirectoryLength = ("sdk/" + group + "/" + artifactId + "/").length();
-        final int fileNameLength = "/reflect-config.json".length();
+        final int fileNameLength = "/resource-config.json".length();
 
-        if (parentDirectoryLength + metaInfPath.length() > (248 - 38)
-            || parentDirectoryLength + metaInfPath.length() + fileNameLength > (260 - 38)) {
+        if (parentDirectoryLength + metaInfPath.length() > (MAX_DIRECTORY_LENGTH - BASE_PATH_LENGTH)
+            || parentDirectoryLength + metaInfPath.length() + fileNameLength > (MAX_PATH_LENGTH - BASE_PATH_LENGTH)) {
             // see
             // https://github.com/Azure/azure-sdk-for-java/blob/main/eng/common/pipelines/templates/steps/verify-path-length.yml
             String shortenedArtifactId = artifactId;

packages/http-client-java/generator/http-client-generator-core/src/test/java/com/microsoft/typespec/http/client/generator/core/util/ClassNameUtilTests.java

@@ -13,27 +13,24 @@ public class ClassNameUtilTests {
 
     @Test
     public void testTruncateClassName() {
-        final int maxFileLength = 260 - 38;
+        final int maxFileLength = ClassNameUtil.MAX_PATH_LENGTH - ClassNameUtil.BASE_PATH_LENGTH;
 
-        // truncate class name
+        // names that previously required truncation now fit
         String name = ClassNameUtil.truncateClassName("com.azure.resourcemanager.deviceprovisioningservices",
             "src/samples/java", "com.azure.resourcemanager.deviceprovisioningservices.generated",
             "IotDpsResourceCheckProvisioningServiceNameAvailability", "Samples");
-        Assertions.assertEquals(maxFileLength,
-            ("sdk/deviceprovisioningservices/azure-resourcemanager-deviceprovisioningservices/src/samples/java/com/azure/resourcemanager/deviceprovisioningservices/generated/"
-                + name + ".java").length());
+        Assertions.assertEquals("IotDpsResourceCheckProvisioningServiceNameAvailabilitySamples", name);
 
         name = ClassNameUtil.truncateClassName("com.azure.resourcemanager.recoveryservicessiterecovery",
             "src/test/java", "com.azure.resourcemanager.recoveryservicessiterecovery.generated",
             "InMageRcmUpdateApplianceForReplicationProtectedItemInput", "Tests");
-        Assertions.assertEquals(maxFileLength,
-            ("sdk/recoveryservicessiterecovery/azure-resourcemanager-recoveryservicessiterecovery/src/test/java/com/azure/resourcemanager/recoveryservicessiterecovery/generated/"
-                + name + ".java").length());
+        Assertions.assertEquals("InMageRcmUpdateApplianceForReplicationProtectedItemInputTests", name);
 
+        // truncate a name that exceeds the relaxed limit
         name = ClassNameUtil.truncateClassName(
             "com.azure.resourcemanager." + KUBERNETES_CONFIGURATION + ".extensiontypes", "src/test/java",
             "com.azure.resourcemanager." + KUBERNETES_CONFIGURATION + ".extensiontypes.generated",
-            "ExtensionTypesLocationGetWithResponse", "MockTests");
+            "ExtensionTypesLocationGetWithResponseAsync", "MockTests");
         Assertions.assertEquals(maxFileLength,
             ("sdk/" + KUBERNETES_CONFIGURATION + "/azure-resourcemanager-" + KUBERNETES_CONFIGURATION
                 + "-extensiontypes/src/test/java/com/azure/resourcemanager/" + KUBERNETES_CONFIGURATION
@@ -53,12 +50,12 @@ public void testTruncateClassName() {
 
     @Test
     public void testGetDirectoryNameForGraalVmConfig() {
-        // directory length over 210
+        // directory length over 218
         String directoryName = ClassNameUtil.getDirectoryNameForGraalVmConfig("com.azure.resourcemanager",
-            "azure-resourcemanager-" + KUBERNETES_CONFIGURATION + "-extensiontypes");
+            "azure-resourcemanager-" + KUBERNETES_CONFIGURATION + "-extensiontypesabc");
         Assertions.assertFalse(directoryName.contains("azure-resourcemanager-"));
 
-        // directory length not over 210, but full filename length over 222
+        // reflect-config.json fits exactly at 230, but resource-config.json exceeds the limit by one
         directoryName = ClassNameUtil.getDirectoryNameForGraalVmConfig("com.azure.resourcemanager",
             "azure-resourcemanager-" + "recovery" + "services" + "data" + "replication");
         Assertions.assertFalse(directoryName.contains("azure-resourcemanager-"));