Prevent the error when explicitly specifying default buf gen template…

… file path

src/main/kotlin/build/buf/gradle/GenerateTask.kt

@@ -50,8 +50,10 @@ abstract class GenerateTask : DefaultTask() {
                 check(specifiedTemplateFile != null) {
                     "Specified templateFileLocation does not exist."
                 }
-                check(defaultTemplateFile == null) {
-                    "Buf gen template file specified in the project directory as well as with templateFileLocation; pick one."
+                if (specifiedTemplateFile != defaultTemplateFile) {
+                    check(defaultTemplateFile == null) {
+                        "Buf gen template file specified in the project directory as well as with templateFileLocation; pick one."
+                    }
                 }
                 specifiedTemplateFile
             } else {

src/test/kotlin/build/buf/gradle/AbstractGenerateTest.kt

@@ -43,6 +43,11 @@ abstract class AbstractGenerateTest : AbstractBufIntegrationTest() {
         gradleRunner().withArguments(BUILD_TASK_NAME).build()
     }
 
+    @Test
+    fun `buf generate with default template file path explicitly specifying`() {
+        gradleRunner().withArguments(BUILD_TASK_NAME).build()
+    }
+
     @Test
     fun `buf generate fails with a nonexistent specified template file`() {
         val result = gradleRunner().withArguments(BUF_GENERATE_TASK_NAME).buildAndFail()

src/test/resources/GenerateTest/buf_generate_with_default_template_file_path_explicitly_specifying/buf.gen.yaml

@@ -0,0 +1,4 @@
+version: v1
+plugins:
+  - plugin: buf.build/protocolbuffers/java:v23.4
+    out: java

src/test/resources/GenerateTest/buf_generate_with_default_template_file_path_explicitly_specifying/buf/test/v1/test.proto

@@ -0,0 +1,21 @@
+// Copyright 2023 Buf Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+syntax = "proto3";
+
+package buf.test.v1;
+
+option java_package = "buf.test.v1";
+
+message BasicMessage {}

src/test/resources/GenerateTest/buf_generate_with_default_template_file_path_explicitly_specifying/build.gradle

@@ -0,0 +1,24 @@
+plugins {
+  id 'java'
+  id 'build.buf'
+}
+
+repositories {
+  mavenCentral()
+}
+
+buf {
+  generate {
+    templateFileLocation = project.file("./buf.gen.yaml")
+  }
+}
+
+compileJava.dependsOn 'bufGenerate'
+
+sourceSets.main.java {
+  srcDir 'build/bufbuild/generated/java'
+}
+
+dependencies {
+  implementation "com.google.protobuf:protobuf-java:$protobufVersion"
+}

src/test/resources/GenerateTest/buf_generate_with_default_template_file_path_explicitly_specifying/src/main/java/buf/test/v1/Foo.java

@@ -0,0 +1,21 @@
+// Copyright 2023 Buf Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package buf.test.v1;
+
+public class Foo {
+    public static void test() {
+        Test.BasicMessage.newBuilder().build();
+    }
+}

src/test/resources/GenerateWithWorkspaceTest/buf_generate_with_default_template_file_path_explicitly_specifying/buf.gen.yaml

@@ -0,0 +1,4 @@
+version: v1
+plugins:
+  - plugin: buf.build/protocolbuffers/java:v23.4
+    out: java

src/test/resources/GenerateWithWorkspaceTest/buf_generate_with_default_template_file_path_explicitly_specifying/buf.work.yaml

@@ -0,0 +1,3 @@
+version: v1
+directories:
+  - workspace

src/test/resources/GenerateWithWorkspaceTest/buf_generate_with_default_template_file_path_explicitly_specifying/build.gradle

@@ -0,0 +1,24 @@
+plugins {
+  id 'java'
+  id 'build.buf'
+}
+
+repositories {
+  mavenCentral()
+}
+
+buf {
+  generate {
+    templateFileLocation = project.file("./buf.gen.yaml")
+  }
+}
+
+compileJava.dependsOn 'bufGenerate'
+
+sourceSets.main.java {
+  srcDir 'build/bufbuild/generated/java'
+}
+
+dependencies {
+  implementation "com.google.protobuf:protobuf-java:$protobufVersion"
+}

src/test/resources/GenerateWithWorkspaceTest/buf_generate_with_default_template_file_path_explicitly_specifying/src/main/java/buf/test/v1/Foo.java

@@ -0,0 +1,21 @@
+// Copyright 2023 Buf Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package buf.test.v1;
+
+public class Foo {
+    public static void test() {
+        Test.BasicMessage.newBuilder().build();
+    }
+}

src/test/resources/GenerateWithWorkspaceTest/buf_generate_with_default_template_file_path_explicitly_specifying/workspace/buf/test/v1/test.proto

@@ -0,0 +1,21 @@
+// Copyright 2023 Buf Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+syntax = "proto3";
+
+package buf.test.v1;
+
+option java_package = "buf.test.v1";
+
+message BasicMessage {}