Base setup for i18n for server with go-i18n library

assets/i18n/active.en.json

@@ -0,0 +1,3 @@
+{
+    "github.command.help.title": "###### Mattermost GitHub Plugin - Slash Command Help\n"
+}

go.mod

@@ -8,6 +8,7 @@ require (
 	github.com/gorilla/mux v1.8.1
 	github.com/mattermost/mattermost/server/public v0.0.15
 	github.com/microcosm-cc/bluemonday v1.0.19
+	github.com/nicksnyder/go-i18n/v2 v2.4.0
 	github.com/pkg/errors v0.9.1
 	github.com/stretchr/testify v1.8.4
 	golang.org/x/oauth2 v0.17.0

go.sum

@@ -8,6 +8,8 @@ dmitri.shuralyov.com/service/change v0.0.0-20181023043359-a85b471d5412/go.mod h1
 dmitri.shuralyov.com/state v0.0.0-20180228185332-28bcc343414c/go.mod h1:0PRwlb0D6DFvNNtx+9ybjezNCa8XF0xaYcETyp6rHWU=
 git.apache.org/thrift.git v0.0.0-20180902110319-2566ecd5d999/go.mod h1:fPE2ZNJGynbRyZ4dJvy6G277gSllfV2HJqblrnkyeyg=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
+github.com/BurntSushi/toml v1.3.2 h1:o7IhLm0Msx3BaB+n3Ag7L8EVlByGnpq14C4YWiu/gL8=
+github.com/BurntSushi/toml v1.3.2/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
 github.com/Masterminds/goutils v1.1.1 h1:5nUrii3FMTL5diU80unEVvNevw1nH4+ZV4DSLVJLSYI=
 github.com/Masterminds/goutils v1.1.1/go.mod h1:8cTjp+g8YejhMuvIA5y2vz3BpJxksy863GQaJW2MFNU=
 github.com/Masterminds/semver/v3 v3.1.1 h1:hLg3sBzpNErnxhQtUy/mmLR2I9foDujNK030IGemrRc=
@@ -154,6 +156,8 @@ github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJ
 github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/neelance/astrewrite v0.0.0-20160511093645-99348263ae86/go.mod h1:kHJEU3ofeGjhHklVoIGuVj85JJwZ6kWPaJwCIxgnFmo=
 github.com/neelance/sourcemap v0.0.0-20151028013722-8c68805598ab/go.mod h1:Qr6/a/Q4r9LP1IltGz7tA7iOK1WonHEYhu1HRBA7ZiM=
+github.com/nicksnyder/go-i18n/v2 v2.4.0 h1:3IcvPOAvnCKwNm0TB0dLDTuawWEj+ax/RERNC+diLMM=
+github.com/nicksnyder/go-i18n/v2 v2.4.0/go.mod h1:nxYSZE9M0bf3Y70gPQjN9ha7XNHX7gMc814+6wVyEI4=
 github.com/oklog/run v1.1.0 h1:GEenZ1cK0+q0+wsJew9qUg/DyD8k3JzYsZAi5gYi2mA=
 github.com/oklog/run v1.1.0/go.mod h1:sVPdnTZT1zYwAJeCMu2Th4T21pA3FPOQRfWjQlk7DVU=
 github.com/openzipkin/zipkin-go v0.1.1/go.mod h1:NtoC/o8u3JlF1lSlyPNswIbeQH9bJTmOf0Erfk+hxe8=

server/plugin/command.go

@@ -12,6 +12,7 @@ import (
 	"github.com/mattermost/mattermost/server/public/model"
 	"github.com/mattermost/mattermost/server/public/plugin"
 	"github.com/mattermost/mattermost/server/public/pluginapi/experimental/command"
+	"github.com/nicksnyder/go-i18n/v2/i18n"
 )
 
 const (
@@ -609,14 +610,22 @@ func (p *Plugin) handleMe(_ *plugin.Context, _ *model.CommandArgs, _ []string, u
 	return text
 }
 
-func (p *Plugin) handleHelp(_ *plugin.Context, _ *model.CommandArgs, _ []string, _ *GitHubUserInfo) string {
+func (p *Plugin) handleHelp(_ *plugin.Context, args *model.CommandArgs, _ []string, _ *GitHubUserInfo) string {
+	l := p.b.GetUserLocalizer(args.UserId)
 	message, err := renderTemplate("helpText", p.getConfiguration())
 	if err != nil {
 		p.client.Log.Warn("Failed to render help template", "error", err.Error())
 		return "Encountered an error posting help text."
 	}
 
-	return "###### Mattermost GitHub Plugin - Slash Command Help\n" + message
+	helpTitle := p.b.LocalizeWithConfig(l, &i18n.LocalizeConfig{
+		DefaultMessage: &i18n.Message{
+			ID:    "github.command.help.title",
+			Other: "###### Mattermost GitHub Plugin - Slash Command help\n",
+		},
+	})
+
+	return helpTitle + message
 }
 
 func (p *Plugin) handleSettings(_ *plugin.Context, _ *model.CommandArgs, parameters []string, userInfo *GitHubUserInfo) string {

server/plugin/plugin.go

@@ -23,6 +23,7 @@ import (
 	"github.com/mattermost/mattermost/server/public/pluginapi/experimental/bot/logger"
 	"github.com/mattermost/mattermost/server/public/pluginapi/experimental/bot/poster"
 	"github.com/mattermost/mattermost/server/public/pluginapi/experimental/telemetry"
+	"github.com/mattermost/mattermost/server/public/pluginapi/i18n"
 
 	"github.com/mattermost/mattermost-plugin-github/server/plugin/graphql"
 )
@@ -95,6 +96,8 @@ type Plugin struct {
 	poster      poster.Poster
 	flowManager *FlowManager
 
+	b *i18n.Bundle
+
 	CommandHandlers map[string]CommandHandleFunc
 
 	// githubPermalinkRegex is used to parse github permalinks in post messages.
@@ -267,6 +270,12 @@ func (p *Plugin) OnActivate() error {
 	p.webhookBroker = NewWebhookBroker(p.sendGitHubPingEvent)
 	p.oauthBroker = NewOAuthBroker(p.sendOAuthCompleteEvent)
 
+	i18nBundle, err := i18n.InitBundle(p.API, filepath.Join("assets", "i18n"))
+	if err != nil {
+		return err
+	}
+	p.b = i18nBundle
+
 	botID, err := p.client.Bot.EnsureBot(&model.Bot{
 		OwnerId:     Manifest.Id, // Workaround to support older server version affected by https://github.com/mattermost/mattermost-server/pull/21560
 		Username:    "github",