Add support for partial state in send_join responses

federationclient.go

@@ -101,10 +101,32 @@ func (ac *FederationClient) MakeJoin(
 // See https://matrix.org/docs/spec/server_server/unstable.html#joining-rooms
 func (ac *FederationClient) SendJoin(
 	ctx context.Context, s ServerName, event *Event,
+) (res RespSendJoin, err error) {
+	return ac.sendJoin(ctx, s, event, false)
+}
+
+// SendJoinPartialState sends a join m.room.member event obtained using MakeJoin via a
+// remote matrix server, with a parameter indicating we support partial state in
+// the response.
+// This is used to join a room the local server isn't a member of.
+// See https://matrix.org/docs/spec/server_server/unstable.html#joining-rooms
+func (ac *FederationClient) SendJoinPartialState(
+	ctx context.Context, s ServerName, event *Event,
+) (res RespSendJoin, err error) {
+	return ac.sendJoin(ctx, s, event, true)
+}
+
+// sendJoin is an internal implementation shared between SendJoin and SendJoinPartialState
+func (ac *FederationClient) sendJoin(
+	ctx context.Context, s ServerName, event *Event, partialState bool,
 ) (res RespSendJoin, err error) {
 	path := federationPathPrefixV2 + "/send_join/" +
 		url.PathEscape(event.RoomID()) + "/" +
 		url.PathEscape(event.EventID())
+	if partialState {
+		path += "?org.matrix.msc3706.partial_state=true"
+	}
+
 	req := NewFederationRequest("PUT", s, path)
 	if err = req.SetContent(event); err != nil {
 		return

federationtypes.go

@@ -473,6 +473,10 @@ type RespSendJoin struct {
 	// The returned join event from the remote server. Used for restricted joins,
 	// but not guaranteed to be present as it's only since MSC3083.
 	Event *Event `json:"event,omitempty"`
+	// true if the state is incomplete
+	PartialState bool `json:"org.matrix.msc3706.partial_state"`
+	// a list of servers in the room. Only returned if partial_state is set.
+	ServersInRoom []string `json:"org.matrix.msc3706.servers_in_room"`
 }
 
 // MarshalJSON implements json.Marshaller
@@ -488,7 +492,17 @@ func (r RespSendJoin) MarshalJSON() ([]byte, error) {
 	if len(fields.StateEvents) == 0 {
 		fields.StateEvents = EventJSONs{}
 	}
-	return json.Marshal(fields)
+
+	if !r.PartialState {
+		return json.Marshal(fields)
+	}
+
+	partialJoinFields := respSendJoinPartialStateFields{
+		respSendJoinFields: fields,
+		PartialState:       true,
+		ServersInRoom:      r.ServersInRoom,
+	}
+	return json.Marshal(partialJoinFields)
 }
 
 // ToRespState returns a new RespState with the same data from the given RespPeek
@@ -505,12 +519,21 @@ func (r RespPeek) ToRespState() RespState {
 	}
 }
 
+// respSendJoinFields is an intermediate struct used in RespSendJoin.MarshalJSON
 type respSendJoinFields struct {
 	StateEvents EventJSONs `json:"state"`
 	AuthEvents  EventJSONs `json:"auth_chain"`
 	Origin      ServerName `json:"origin"`
 }
 
+// respSendJoinPartialStateFields extends respSendJoinFields with the fields added
+// when the response has incomplete state.
+type respSendJoinPartialStateFields struct {
+	respSendJoinFields
+	PartialState  bool     `json:"org.matrix.msc3706.partial_state"`
+	ServersInRoom []string `json:"org.matrix.msc3706.servers_in_room"`
+}
+
 // ToRespState returns a new RespState with the same data from the given RespSendJoin
 func (r RespSendJoin) ToRespState() RespState {
 	if len(r.StateEvents) == 0 {

federationtypes_test.go

@@ -2,7 +2,11 @@ package gomatrixserverlib
 
 import (
 	"encoding/json"
+	"strings"
 	"testing"
+	"unicode"
+
+	"github.com/google/go-cmp/cmp"
 )
 
 const emptyRespStateResponse = `{"pdus":[],"auth_chain":[]}`
@@ -90,38 +94,68 @@ func TestRespStateUnmarshalJSON(t *testing.T) {
 }
 
 func TestRespSendJoinMarshalJSON(t *testing.T) {
+	// we unmarshall and marshall an empty send-join response, and check it round-trips correctly.
 	inputData := `{"state":[],"auth_chain":[],"origin":""}`
 	var input RespSendJoin
 	if err := json.Unmarshal([]byte(inputData), &input); err != nil {
 		t.Fatal(err)
 	}
 
+	want := RespSendJoin{
+		StateEvents: []RawJSON{},
+		AuthEvents:  []RawJSON{},
+		Origin:      "",
+	}
+	if !cmp.Equal(input, want, cmp.AllowUnexported(RespSendJoin{})) {
+		t.Errorf("json.Unmarshal(%s): wanted %+v, got %+v", inputData, want, input)
+	}
+
 	gotBytes, err := json.Marshal(input)
 	if err != nil {
 		t.Fatal(err)
 	}
-
 	got := string(gotBytes)
-
 	if emptyRespSendJoinResponse != got {
-		t.Errorf("json.Marshal(RespSendJoin(%q)): wanted %q, got %q", inputData, emptyRespStateResponse, got)
+		t.Errorf("json.Marshal(%+v): wanted '%s', got '%s'", input, emptyRespSendJoinResponse, got)
 	}
 }
 
-func TestRespSendJoinUnmarshalJSON(t *testing.T) {
-	inputData := `{"state":[],"auth_chain":[],"origin":""}`
+func TestRespSendJoinMarshalJSONPartialState(t *testing.T) {
+	inputData := `{
+		"state":[],"auth_chain":[],"origin":"o1",
+		"org.matrix.msc3706.partial_state":true,
+		"org.matrix.msc3706.servers_in_room":["s1", "s2"]
+	}`
+
 	var input RespSendJoin
 	if err := json.Unmarshal([]byte(inputData), &input); err != nil {
 		t.Fatal(err)
 	}
 
+	want := RespSendJoin{
+		StateEvents:   []RawJSON{},
+		AuthEvents:    []RawJSON{},
+		Origin:        "o1",
+		PartialState:  true,
+		ServersInRoom: []string{"s1", "s2"},
+	}
+	if !cmp.Equal(input, want, cmp.AllowUnexported(RespSendJoin{})) {
+		t.Errorf("json.Unmarshal(%s): wanted %+v, got %+v", inputData, want, input)
+	}
+
 	gotBytes, err := json.Marshal(input)
 	if err != nil {
 		t.Fatal(err)
 	}
 	got := string(gotBytes)
-
-	if emptyRespSendJoinResponse != got {
-		t.Errorf("json.Marshal(RespSendJoin(%q)): wanted %q, got %q", inputData, emptyRespStateResponse, got)
+	// the result should be the input, with spaces removed
+	wantJSON := strings.Map(func(r rune) rune {
+		if unicode.IsSpace(r) {
+			return -1
+		}
+		return r
+	}, inputData)
+	if wantJSON != got {
+		t.Errorf("json.Marshal(%+v):\n  wanted: '%s'\n     got: '%s'", input, wantJSON, got)
 	}
 }

go.mod

@@ -2,7 +2,7 @@ module github.com/matrix-org/gomatrixserverlib
 
 require (
 	github.com/frankban/quicktest v1.7.2 // indirect
-	github.com/google/go-cmp v0.4.0 // indirect
+	github.com/google/go-cmp v0.4.0
 	github.com/konsorten/go-windows-terminal-sequences v1.0.2 // indirect
 	github.com/kr/pretty v0.2.0 // indirect
 	github.com/matrix-org/gomatrix v0.0.0-20190528120928-7df988a63f26