MM-11230: Make permissions checks in commands failsafe. (#9392)

Also add additional unit tests to make sure the permissions tests are
completely solid.

app/command_join_test.go

@@ -5,9 +5,11 @@ package app
 
 import (
 	"testing"
-	"github.com/mattermost/mattermost-server/model"
+
 	"github.com/nicksnyder/go-i18n/i18n"
 	"github.com/stretchr/testify/assert"
+
+	"github.com/mattermost/mattermost-server/model"
 )
 
 func TestJoinCommandNoChannel(t *testing.T) {
@@ -20,10 +22,11 @@ func TestJoinCommandNoChannel(t *testing.T) {
 
 	cmd := &JoinProvider{}
 	resp := cmd.DoCommand(th.App, &model.CommandArgs{
-		T:      i18n.IdentityTfunc(),
-		UserId: th.BasicUser2.Id,
+		T:       i18n.IdentityTfunc(),
+		UserId:  th.BasicUser2.Id,
 		SiteURL: "http://test.url",
-		TeamId:      th.BasicTeam.Id,
+		TeamId:  th.BasicTeam.Id,
+		Session: model.Session{UserId: th.BasicUser.Id, TeamMembers: []*model.TeamMember{{TeamId: th.BasicTeam.Id, Roles: model.TEAM_USER_ROLE_ID}}},
 	}, "asdsad")
 
 	assert.Equal(t, "api.command_join.list.app_error", resp.Text)
@@ -38,20 +41,20 @@ func TestJoinCommandForExistingChannel(t *testing.T) {
 	}
 
 	channel2, _ := th.App.CreateChannel(&model.Channel{
-	  DisplayName: "AA",
-	  Name:        "aa" + model.NewId() + "a",
-	  Type:        model.CHANNEL_OPEN,
-	  TeamId:      th.BasicTeam.Id,
-	  CreatorId:   th.BasicUser.Id,
+		DisplayName: "AA",
+		Name:        "aa" + model.NewId() + "a",
+		Type:        model.CHANNEL_OPEN,
+		TeamId:      th.BasicTeam.Id,
+		CreatorId:   th.BasicUser.Id,
 	}, false)
 
-
 	cmd := &JoinProvider{}
 	resp := cmd.DoCommand(th.App, &model.CommandArgs{
-		T:      i18n.IdentityTfunc(),
-		UserId: th.BasicUser2.Id,
+		T:       i18n.IdentityTfunc(),
+		UserId:  th.BasicUser2.Id,
 		SiteURL: "http://test.url",
-		TeamId:      th.BasicTeam.Id,
+		TeamId:  th.BasicTeam.Id,
+		Session: model.Session{UserId: th.BasicUser.Id, TeamMembers: []*model.TeamMember{{TeamId: th.BasicTeam.Id, Roles: model.TEAM_USER_ROLE_ID}}},
 	}, channel2.Name)
 
 	assert.Equal(t, "", resp.Text)
@@ -67,22 +70,81 @@ func TestJoinCommandWithTilde(t *testing.T) {
 	}
 
 	channel2, _ := th.App.CreateChannel(&model.Channel{
-	  DisplayName: "AA",
-	  Name:        "aa" + model.NewId() + "a",
-	  Type:        model.CHANNEL_OPEN,
-	  TeamId:      th.BasicTeam.Id,
-	  CreatorId:   th.BasicUser.Id,
+		DisplayName: "AA",
+		Name:        "aa" + model.NewId() + "a",
+		Type:        model.CHANNEL_OPEN,
+		TeamId:      th.BasicTeam.Id,
+		CreatorId:   th.BasicUser.Id,
 	}, false)
 
-
 	cmd := &JoinProvider{}
 	resp := cmd.DoCommand(th.App, &model.CommandArgs{
-		T:      i18n.IdentityTfunc(),
-		UserId: th.BasicUser2.Id,
+		T:       i18n.IdentityTfunc(),
+		UserId:  th.BasicUser2.Id,
 		SiteURL: "http://test.url",
-		TeamId:      th.BasicTeam.Id,
+		TeamId:  th.BasicTeam.Id,
+		Session: model.Session{UserId: th.BasicUser.Id, TeamMembers: []*model.TeamMember{{TeamId: th.BasicTeam.Id, Roles: model.TEAM_USER_ROLE_ID}}},
 	}, "~"+channel2.Name)
 
 	assert.Equal(t, "", resp.Text)
 	assert.Equal(t, "http://test.url/"+th.BasicTeam.Name+"/channels/"+channel2.Name, resp.GotoLocation)
 }
+
+func TestJoinCommandPermissions(t *testing.T) {
+	th := Setup().InitBasic()
+	defer th.TearDown()
+
+	channel2, _ := th.App.CreateChannel(&model.Channel{
+		DisplayName: "AA",
+		Name:        "aa" + model.NewId() + "a",
+		Type:        model.CHANNEL_OPEN,
+		TeamId:      th.BasicTeam.Id,
+		CreatorId:   th.BasicUser.Id,
+	}, false)
+
+	cmd := &JoinProvider{}
+
+	// Try a public channel *without* permission.
+	args := &model.CommandArgs{
+		T:       i18n.IdentityTfunc(),
+		UserId:  th.BasicUser2.Id,
+		SiteURL: "http://test.url",
+		TeamId:  th.BasicTeam.Id,
+		Session: model.Session{UserId: th.BasicUser.Id, TeamMembers: []*model.TeamMember{{TeamId: th.BasicTeam.Id, Roles: ""}}},
+	}
+
+	actual := cmd.DoCommand(th.App, args, "~"+channel2.Name).Text
+	assert.Equal(t, "api.command_join.fail.app_error", actual)
+
+	// Try a public channel with permission.
+	args = &model.CommandArgs{
+		T:       i18n.IdentityTfunc(),
+		UserId:  th.BasicUser2.Id,
+		SiteURL: "http://test.url",
+		TeamId:  th.BasicTeam.Id,
+		Session: model.Session{UserId: th.BasicUser.Id, TeamMembers: []*model.TeamMember{{TeamId: th.BasicTeam.Id, Roles: model.TEAM_USER_ROLE_ID}}},
+	}
+
+	actual = cmd.DoCommand(th.App, args, "~"+channel2.Name).Text
+	assert.Equal(t, "", actual)
+
+	// Try a private channel *without* permission.
+	channel3, _ := th.App.CreateChannel(&model.Channel{
+		DisplayName: "BB",
+		Name:        "aa" + model.NewId() + "a",
+		Type:        model.CHANNEL_PRIVATE,
+		TeamId:      th.BasicTeam.Id,
+		CreatorId:   th.BasicUser.Id,
+	}, false)
+
+	args = &model.CommandArgs{
+		T:       i18n.IdentityTfunc(),
+		UserId:  th.BasicUser2.Id,
+		SiteURL: "http://test.url",
+		TeamId:  th.BasicTeam.Id,
+		Session: model.Session{UserId: th.BasicUser.Id, TeamMembers: []*model.TeamMember{{TeamId: th.BasicTeam.Id, Roles: model.TEAM_USER_ROLE_ID}}},
+	}
+
+	actual = cmd.DoCommand(th.App, args, "~"+channel3.Name).Text
+	assert.Equal(t, "api.command_join.fail.app_error", actual)
+}