Apps.ListRepos/Apps.ListUserRepos: Add mercy-preview + nebula-preview headers (google#1806)

Author: andygrunwald

github/apps_installation.go

@@ -8,6 +8,7 @@ package github
 import (
 	"context"
 	"fmt"
+	"strings"
 )
 
 // ListRepositories represents the response from the list repos endpoints.
@@ -30,6 +31,10 @@ func (s *AppsService) ListRepos(ctx context.Context, opts *ListOptions) (*ListRe
 		return nil, nil, err
 	}
 
+	// TODO: remove custom Accept headers when APIs fully launch.
+	acceptHeaders := []string{mediaTypeTopicsPreview, mediaTypeRepositoryVisibilityPreview}
+	req.Header.Set("Accept", strings.Join(acceptHeaders, ", "))
+
 	var r *ListRepositories
 
 	resp, err := s.client.Do(ctx, req, &r)
@@ -56,6 +61,10 @@ func (s *AppsService) ListUserRepos(ctx context.Context, id int64, opts *ListOpt
 		return nil, nil, err
 	}
 
+	// TODO: remove custom Accept headers when APIs fully launch.
+	acceptHeaders := []string{mediaTypeTopicsPreview, mediaTypeRepositoryVisibilityPreview}
+	req.Header.Set("Accept", strings.Join(acceptHeaders, ", "))
+
 	var r *ListRepositories
 	resp, err := s.client.Do(ctx, req, &r)
 	if err != nil {

github/apps_installation_test.go

@@ -10,15 +10,18 @@ import (
 	"fmt"
 	"net/http"
 	"reflect"
+	"strings"
 	"testing"
 )
 
 func TestAppsService_ListRepos(t *testing.T) {
 	client, mux, _, teardown := setup()
 	defer teardown()
 
+	wantAcceptHeaders := []string{mediaTypeTopicsPreview, mediaTypeRepositoryVisibilityPreview}
 	mux.HandleFunc("/installation/repositories", func(w http.ResponseWriter, r *http.Request) {
 		testMethod(t, r, "GET")
+		testHeader(t, r, "Accept", strings.Join(wantAcceptHeaders, ", "))
 		testFormValues(t, r, values{
 			"page":     "1",
 			"per_page": "2",
@@ -52,8 +55,10 @@ func TestAppsService_ListUserRepos(t *testing.T) {
 	client, mux, _, teardown := setup()
 	defer teardown()
 
+	wantAcceptHeaders := []string{mediaTypeTopicsPreview, mediaTypeRepositoryVisibilityPreview}
 	mux.HandleFunc("/user/installations/1/repositories", func(w http.ResponseWriter, r *http.Request) {
 		testMethod(t, r, "GET")
+		testHeader(t, r, "Accept", strings.Join(wantAcceptHeaders, ", "))
 		testFormValues(t, r, values{
 			"page":     "1",
 			"per_page": "2",