Update mattermost library (#2152)

* Update mattermost library

* Fix linting

vendor/github.com/hashicorp/go-plugin/testing.go

@@ -0,0 +1,185 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package plugin
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"net"
+	"net/rpc"
+
+	hclog "github.com/hashicorp/go-hclog"
+	"github.com/hashicorp/go-plugin/internal/grpcmux"
+	"github.com/mitchellh/go-testing-interface"
+	"google.golang.org/grpc"
+)
+
+// TestOptions allows specifying options that can affect the behavior of the
+// test functions
+type TestOptions struct {
+	//ServerStdout causes the given value to be used in place of a blank buffer
+	//for RPCServer's Stdout
+	ServerStdout io.ReadCloser
+
+	//ServerStderr causes the given value to be used in place of a blank buffer
+	//for RPCServer's Stderr
+	ServerStderr io.ReadCloser
+}
+
+// The testing file contains test helpers that you can use outside of
+// this package for making it easier to test plugins themselves.
+
+// TestConn is a helper function for returning a client and server
+// net.Conn connected to each other.
+func TestConn(t testing.T) (net.Conn, net.Conn) {
+	// Listen to any local port. This listener will be closed
+	// after a single connection is established.
+	l, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	// Start a goroutine to accept our client connection
+	var serverConn net.Conn
+	doneCh := make(chan struct{})
+	go func() {
+		defer close(doneCh)
+		defer l.Close()
+		var err error
+		serverConn, err = l.Accept()
+		if err != nil {
+			t.Fatalf("err: %s", err)
+		}
+	}()
+
+	// Connect to the server
+	clientConn, err := net.Dial("tcp", l.Addr().String())
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	// Wait for the server side to acknowledge it has connected
+	<-doneCh
+
+	return clientConn, serverConn
+}
+
+// TestRPCConn returns a rpc client and server connected to each other.
+func TestRPCConn(t testing.T) (*rpc.Client, *rpc.Server) {
+	clientConn, serverConn := TestConn(t)
+
+	server := rpc.NewServer()
+	go server.ServeConn(serverConn)
+
+	client := rpc.NewClient(clientConn)
+	return client, server
+}
+
+// TestPluginRPCConn returns a plugin RPC client and server that are connected
+// together and configured.
+func TestPluginRPCConn(t testing.T, ps map[string]Plugin, opts *TestOptions) (*RPCClient, *RPCServer) {
+	// Create two net.Conns we can use to shuttle our control connection
+	clientConn, serverConn := TestConn(t)
+
+	// Start up the server
+	server := &RPCServer{Plugins: ps, Stdout: new(bytes.Buffer), Stderr: new(bytes.Buffer)}
+	if opts != nil {
+		if opts.ServerStdout != nil {
+			server.Stdout = opts.ServerStdout
+		}
+		if opts.ServerStderr != nil {
+			server.Stderr = opts.ServerStderr
+		}
+	}
+	go server.ServeConn(serverConn)
+
+	// Connect the client to the server
+	client, err := NewRPCClient(clientConn, ps)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	return client, server
+}
+
+// TestGRPCConn returns a gRPC client conn and grpc server that are connected
+// together and configured. The register function is used to register services
+// prior to the Serve call. This is used to test gRPC connections.
+func TestGRPCConn(t testing.T, register func(*grpc.Server)) (*grpc.ClientConn, *grpc.Server) {
+	// Create a listener
+	l, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	server := grpc.NewServer()
+	register(server)
+	go server.Serve(l)
+
+	// Connect to the server
+	conn, err := grpc.Dial(
+		l.Addr().String(),
+		grpc.WithBlock(),
+		grpc.WithInsecure())
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	// Connection successful, close the listener
+	l.Close()
+
+	return conn, server
+}
+
+// TestPluginGRPCConn returns a plugin gRPC client and server that are connected
+// together and configured. This is used to test gRPC connections.
+func TestPluginGRPCConn(t testing.T, multiplex bool, ps map[string]Plugin) (*GRPCClient, *GRPCServer) {
+	// Create a listener
+	ln, err := serverListener(UnixSocketConfig{})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	logger := hclog.New(&hclog.LoggerOptions{
+		Level: hclog.Debug,
+	})
+
+	// Start up the server
+	var muxer *grpcmux.GRPCServerMuxer
+	if multiplex {
+		muxer = grpcmux.NewGRPCServerMuxer(logger, ln)
+		ln = muxer
+	}
+	server := &GRPCServer{
+		Plugins: ps,
+		DoneCh:  make(chan struct{}),
+		Server:  DefaultGRPCServer,
+		Stdout:  new(bytes.Buffer),
+		Stderr:  new(bytes.Buffer),
+		logger:  logger,
+		muxer:   muxer,
+	}
+	if err := server.Init(); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	go server.Serve(ln)
+
+	client := &Client{
+		address:  ln.Addr(),
+		protocol: ProtocolGRPC,
+		config: &ClientConfig{
+			Plugins:             ps,
+			GRPCBrokerMultiplex: multiplex,
+		},
+		logger: logger,
+	}
+
+	grpcClient, err := newGRPCClient(context.Background(), client)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	return grpcClient, server
+}