From 0d29f14a9afe84adfbc8760b9fad6b394436fd3e Mon Sep 17 00:00:00 2001
From: Preston Van Loon <preston90@gmail.com>
Date: Mon, 24 Jun 2019 11:19:17 -0400
Subject: [PATCH] protoc_gen_swagger: Add attr for single_output (#944)

---
 examples/proto/examplepb/BUILD.bazel |  8 +++-
 protoc-gen-swagger/defs.bzl          | 68 +++++++++++++++++++++-------
 2 files changed, 59 insertions(+), 17 deletions(-)

diff --git a/examples/proto/examplepb/BUILD.bazel b/examples/proto/examplepb/BUILD.bazel
index f5aa149eb8e..dd7a2d45c3c 100644
--- a/examples/proto/examplepb/BUILD.bazel
+++ b/examples/proto/examplepb/BUILD.bazel
@@ -70,6 +70,12 @@ go_library(
 )
 
 protoc_gen_swagger(
-    name = "expamplepb_protoc_gen_swagger",
+    name = "examplepb_protoc_gen_swagger",
     proto = ":examplepb_proto",
 )
+
+protoc_gen_swagger(
+    name = "examplepb_protoc_gen_swagger_merged",
+    proto = ":examplepb_proto",
+    single_output = True,  # Outputs a single swagger.json file.
+)
diff --git a/protoc-gen-swagger/defs.bzl b/protoc-gen-swagger/defs.bzl
index 936ca4791fe..4f90807f0f5 100644
--- a/protoc-gen-swagger/defs.bzl
+++ b/protoc-gen-swagger/defs.bzl
@@ -30,33 +30,38 @@ def _collect_includes(gen_dir, srcs):
 
     return includes
 
-def _run_proto_gen_swagger(ctx, direct_proto_srcs, transitive_proto_srcs, actions, protoc, protoc_gen_swagger, grpc_api_configuration):
+def _run_proto_gen_swagger(ctx, direct_proto_srcs, transitive_proto_srcs, actions, protoc, protoc_gen_swagger, grpc_api_configuration, single_output):
     swagger_files = []
-    for proto in direct_proto_srcs:
-        swagger_file = actions.declare_file(
-            "%s.swagger.json" % proto.basename[:-len(".proto")],
-            sibling = proto,
-        )
 
-        inputs = direct_proto_srcs + transitive_proto_srcs
-        tools = [protoc_gen_swagger]
+    inputs = direct_proto_srcs + transitive_proto_srcs
+    tools = [protoc_gen_swagger]
 
-        options = ["logtostderr=true", "allow_repeated_fields_in_body=true"]
-        if grpc_api_configuration:
-            options.append("grpc_api_configuration=%s" % grpc_api_configuration.path)
-            inputs.append(grpc_api_configuration)
+    options = ["logtostderr=true", "allow_repeated_fields_in_body=true"]
+    if grpc_api_configuration:
+        options.append("grpc_api_configuration=%s" % grpc_api_configuration.path)
+        inputs.append(grpc_api_configuration)
 
+    includes = _collect_includes(ctx.genfiles_dir.path, direct_proto_srcs + transitive_proto_srcs)
+
+    if single_output:
+        swagger_file = actions.declare_file(
+            "%s.swagger.json" % ctx.attr.name,
+            sibling = direct_proto_srcs[0],
+        )
         output_dir = ctx.bin_dir.path
-        if proto.owner.workspace_root:
-            output_dir = "/".join([output_dir, proto.owner.workspace_root])
+        if direct_proto_srcs[0].owner.workspace_root:
+            output_dir = "/".join([output_dir, direct_proto_srcs[0].owner.workspace_root])
+
+        output_dir = "/".join([output_dir, direct_proto_srcs[0].dirname])
 
-        includes = _collect_includes(ctx.genfiles_dir.path, direct_proto_srcs + transitive_proto_srcs)
+        options.append("allow_merge=true")
+        options.append("merge_file_name=%s" % ctx.attr.name)
 
         args = actions.args()
         args.add("--plugin=%s" % protoc_gen_swagger.path)
         args.add("--swagger_out=%s:%s" % (",".join(options), output_dir))
         args.add_all(["-I%s" % include for include in includes])
-        args.add(proto.path)
+        args.add_all([src.path for src in direct_proto_srcs])
 
         actions.run(
             executable = protoc,
@@ -67,6 +72,32 @@ def _run_proto_gen_swagger(ctx, direct_proto_srcs, transitive_proto_srcs, action
         )
 
         swagger_files.append(swagger_file)
+    else:
+        for proto in direct_proto_srcs:
+            swagger_file = actions.declare_file(
+                "%s.swagger.json" % proto.basename[:-len(".proto")],
+                sibling = proto,
+            )
+
+            output_dir = ctx.bin_dir.path
+            if proto.owner.workspace_root:
+                output_dir = "/".join([output_dir, proto.owner.workspace_root])
+
+            args = actions.args()
+            args.add("--plugin=%s" % protoc_gen_swagger.path)
+            args.add("--swagger_out=%s:%s" % (",".join(options), output_dir))
+            args.add_all(["-I%s" % include for include in includes])
+            args.add(proto.path)
+
+            actions.run(
+                executable = protoc,
+                inputs = inputs,
+                tools = tools,
+                outputs = [swagger_file],
+                arguments = [args],
+            )
+
+            swagger_files.append(swagger_file)
 
     return swagger_files
 
@@ -84,6 +115,7 @@ def _proto_gen_swagger_impl(ctx):
                 protoc = ctx.executable._protoc,
                 protoc_gen_swagger = ctx.executable._protoc_gen_swagger,
                 grpc_api_configuration = grpc_api_configuration,
+                single_output = ctx.attr.single_output,
             ),
         ),
     )]
@@ -99,6 +131,10 @@ protoc_gen_swagger = rule(
             allow_single_file = True,
             mandatory = False,
         ),
+        "single_output": attr.bool(
+            default = False,
+            mandatory = False,
+        ),
         "_protoc": attr.label(
             default = "@com_google_protobuf//:protoc",
             executable = True,