Add /help slash command (#6650)

* Add /help slash command

* Fix copyright year

* go fmt

* Add help command test at api4

* Fix jasonblais's issue

* Update test code

* Fix unit test issue - keep config unchanged

5 files changed, 123 insertions, 1 deletions

diff --git a/api/command_help_test.go b/api/command_help_test.go
new file mode 100644
index 000000000..20fa8c830
--- /dev/null
+++ b/api/command_help_test.go
@@ -0,0 +1,33 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package api
+
+import (
+	"github.com/mattermost/platform/model"
+	"github.com/mattermost/platform/utils"
+	"testing"
+)
+
+func TestHelpCommand(t *testing.T) {
+	th := Setup().InitBasic()
+	Client := th.BasicClient
+	channel := th.BasicChannel
+
+	HelpLink := *utils.Cfg.SupportSettings.HelpLink
+	defer func() {
+		*utils.Cfg.SupportSettings.HelpLink = HelpLink
+	}()
+
+	*utils.Cfg.SupportSettings.HelpLink = ""
+	rs1 := Client.Must(Client.Command(channel.Id, "/help ")).Data.(*model.CommandResponse)
+	if rs1.GotoLocation != model.SUPPORT_SETTINGS_DEFAULT_HELP_LINK {
+		t.Fatal("failed to default help link")
+	}
+
+	*utils.Cfg.SupportSettings.HelpLink = "https://docs.mattermost.com/guides/user.html"
+	rs2 := Client.Must(Client.Command(channel.Id, "/help ")).Data.(*model.CommandResponse)
+	if rs2.GotoLocation != "https://docs.mattermost.com/guides/user.html" {
+		t.Fatal("failed to help link")
+	}
+}
diff --git a/api4/command_help_test.go b/api4/command_help_test.go
new file mode 100644
index 000000000..cb0f1b634
--- /dev/null
+++ b/api4/command_help_test.go
@@ -0,0 +1,33 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package api4
+
+import (
+	"github.com/mattermost/platform/model"
+	"github.com/mattermost/platform/utils"
+	"testing"
+)
+
+func TestHelpCommand(t *testing.T) {
+	th := Setup().InitBasic()
+	Client := th.Client
+	channel := th.BasicChannel
+
+	HelpLink := *utils.Cfg.SupportSettings.HelpLink
+	defer func() {
+		*utils.Cfg.SupportSettings.HelpLink = HelpLink
+	}()
+
+	*utils.Cfg.SupportSettings.HelpLink = ""
+	rs1, _ := Client.ExecuteCommand(channel.Id, "/help ")
+	if rs1.GotoLocation != model.SUPPORT_SETTINGS_DEFAULT_HELP_LINK {
+		t.Fatal("failed to default help link")
+	}
+
+	*utils.Cfg.SupportSettings.HelpLink = "https://docs.mattermost.com/guides/user.html"
+	rs2, _ := Client.ExecuteCommand(channel.Id, "/help ")
+	if rs2.GotoLocation != "https://docs.mattermost.com/guides/user.html" {
+		t.Fatal("failed to help link")
+	}
+}
diff --git a/app/command_help.go b/app/command_help.go
new file mode 100644
index 000000000..e545865fc
--- /dev/null
+++ b/app/command_help.go
@@ -0,0 +1,44 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package app
+
+import (
+	"github.com/mattermost/platform/model"
+	"github.com/mattermost/platform/utils"
+	goi18n "github.com/nicksnyder/go-i18n/i18n"
+)
+
+type HelpProvider struct {
+}
+
+const (
+	CMD_HELP = "help"
+)
+
+func init() {
+	RegisterCommandProvider(&HelpProvider{})
+}
+
+func (h *HelpProvider) GetTrigger() string {
+	return CMD_HELP
+}
+
+func (h *HelpProvider) GetCommand(T goi18n.TranslateFunc) *model.Command {
+	return &model.Command{
+		Trigger:          CMD_HELP,
+		AutoComplete:     true,
+		AutoCompleteDesc: T("api.command_help.desc"),
+		DisplayName:      T("api.command_help.name"),
+	}
+}
+
+func (h *HelpProvider) DoCommand(args *model.CommandArgs, message string) *model.CommandResponse {
+	helpLink := *utils.Cfg.SupportSettings.HelpLink
+
+	if helpLink == "" {
+		helpLink = model.SUPPORT_SETTINGS_DEFAULT_HELP_LINK
+	}
+
+	return &model.CommandResponse{GotoLocation: helpLink}
+}
diff --git a/i18n/en.json b/i18n/en.json
index 6371522a4..ff34cf54f 100644
--- a/i18n/en.json
+++ b/i18n/en.json
@@ -872,6 +872,14 @@
     "translation": "shrug"
   },
   {
+    "id": "api.command_help.desc",
+    "translation": "Open the Mattermost help page"
+  },
+  {
+    "id": "api.command_help.name",
+    "translation": "help"
+  },
+  {
     "id": "api.compliance.init.debug",
     "translation": "Initializing compliance API routes"
   },
diff --git a/webapp/components/create_comment.jsx b/webapp/components/create_comment.jsx
index 56e9eb88f..2ddc828cc 100644
--- a/webapp/components/create_comment.jsx
+++ b/webapp/components/create_comment.jsx
@@ -203,7 +203,11 @@ export default class CreateComment extends React.Component {
             (data) => {
                 this.setState({submitting: false});
                 if (data.goto_location && data.goto_location.length > 0) {
-                    browserHistory.push(data.goto_location);
+                    if (data.goto_location.startsWith('/') || data.goto_location.includes(window.location.hostname)) {
+                        browserHistory.push(data.goto_location);
+                    } else {
+                        window.open(data.goto_location);
+                    }
                 }
             },
             (err) => {