From 045e1eedef3379db477aff0f0fa5a327c55ea8a9 Mon Sep 17 00:00:00 2001
From: Ivan Balaksha <tagantroy@gmail.com>
Date: Wed, 13 May 2020 20:59:36 +0100
Subject: [PATCH] Fix problem with underscores in rpc names

---
 .../generator/TopLevelConstantsGenerator.kt   |  8 +++++-
 .../generator/protoc/ProtoMethodName.kt       | 19 +++++++++++--
 .../generator/protoc/ProtoMethodNameTest.kt   | 28 +++++++++++++++++++
 .../rpc_name_contains_underscore.proto        |  9 ++++++
 4 files changed, 61 insertions(+), 3 deletions(-)
 create mode 100644 compiler/src/test/java/io/grpc/kotlin/generator/protoc/ProtoMethodNameTest.kt
 create mode 100644 compiler/src/test/proto/testing/rpc_name_contains_underscore.proto

diff --git a/compiler/src/main/java/io/grpc/kotlin/generator/TopLevelConstantsGenerator.kt b/compiler/src/main/java/io/grpc/kotlin/generator/TopLevelConstantsGenerator.kt
index 44f8a60c..d46aa0a8 100644
--- a/compiler/src/main/java/io/grpc/kotlin/generator/TopLevelConstantsGenerator.kt
+++ b/compiler/src/main/java/io/grpc/kotlin/generator/TopLevelConstantsGenerator.kt
@@ -43,7 +43,13 @@ class TopLevelConstantsGenerator(config: GeneratorConfig): ServiceCodeGenerator(
             .getter(
               FunSpec.getterBuilder()
                 .addAnnotation(JvmStatic::class)
-                .addStatement("return %T.get%LMethod()", service.grpcClass, method.methodName)
+                .addStatement("return %T.%L()",
+                  service.grpcClass,
+                  method.methodName
+                    .toMemberSimpleName()
+                    .withPrefix("get")
+                    .withSuffix("Method")
+                )
                 .build()
             )
             .build()
diff --git a/compiler/src/main/java/io/grpc/kotlin/generator/protoc/ProtoMethodName.kt b/compiler/src/main/java/io/grpc/kotlin/generator/protoc/ProtoMethodName.kt
index 05031cc4..0ed4ee1b 100644
--- a/compiler/src/main/java/io/grpc/kotlin/generator/protoc/ProtoMethodName.kt
+++ b/compiler/src/main/java/io/grpc/kotlin/generator/protoc/ProtoMethodName.kt
@@ -22,8 +22,23 @@ import com.google.protobuf.Descriptors.MethodDescriptor
 
 /** Represents the unqualified name of an RPC method in a proto file, in UpperCamelCase. */
 data class ProtoMethodName(val name: String) : CharSequence by name {
-  fun toMemberSimpleName(): MemberSimpleName =
-    MemberSimpleName(CaseFormat.UPPER_CAMEL.to(CaseFormat.LOWER_CAMEL, name))
+  fun toMemberSimpleName(): MemberSimpleName {
+    val name = MemberSimpleName(CaseFormat.UPPER_CAMEL.to(CaseFormat.LOWER_CAMEL, name))
+    if (containsSpecialCharacters(name)) {
+      return handleSpecialCharacters(name)
+    }
+    return name
+  }
+
+  private fun containsSpecialCharacters(name: MemberSimpleName): Boolean {
+    return name.contains("_")
+  }
+
+  private fun handleSpecialCharacters(name: MemberSimpleName): MemberSimpleName {
+    return name.split("_")
+      .map(::MemberSimpleName)
+      .reduce { acc, simpleName -> acc + simpleName }
+  }
 
   override fun toString() = name
 }
diff --git a/compiler/src/test/java/io/grpc/kotlin/generator/protoc/ProtoMethodNameTest.kt b/compiler/src/test/java/io/grpc/kotlin/generator/protoc/ProtoMethodNameTest.kt
new file mode 100644
index 00000000..8a9c18e7
--- /dev/null
+++ b/compiler/src/test/java/io/grpc/kotlin/generator/protoc/ProtoMethodNameTest.kt
@@ -0,0 +1,28 @@
+package io.grpc.kotlin.generator.protoc
+
+import com.google.common.truth.Truth.assertThat
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+
+/** Tests for [ProtoMethodName]. */
+@RunWith(JUnit4::class)
+class ProtoMethodNameTest {
+  @Test
+  fun toMemberSimpleNameWithSingleUnderscore(){
+    assertThat(ProtoMethodName("say_hello").toMemberSimpleName())
+      .isEqualTo(MemberSimpleName("sayHello"))
+  }
+
+  @Test
+  fun toMemberSimpleNameWithMultipleUnderscores(){
+    assertThat(ProtoMethodName("say_hello_again").toMemberSimpleName())
+      .isEqualTo(MemberSimpleName("sayHelloAgain"))
+  }
+
+  @Test
+  fun toMemberSimpleNameWithRecommendedNamingStyle(){
+    assertThat(ProtoMethodName("SayHello").toMemberSimpleName())
+      .isEqualTo(MemberSimpleName("sayHello"))
+  }
+}
\ No newline at end of file
diff --git a/compiler/src/test/proto/testing/rpc_name_contains_underscore.proto b/compiler/src/test/proto/testing/rpc_name_contains_underscore.proto
new file mode 100644
index 00000000..196e091b
--- /dev/null
+++ b/compiler/src/test/proto/testing/rpc_name_contains_underscore.proto
@@ -0,0 +1,9 @@
+syntax = "proto3";
+package io.grpc.testing.underscore;
+option java_multiple_files = true;
+service NameContainsUnderscore {
+    rpc say_hello (HelloRequest) returns (HelloReply);
+    rpc say_hello_again (HelloRequest) returns (HelloReply);
+}
+message HelloRequest {}
+message HelloReply {}
\ No newline at end of file