[MM-16709] Add helper method for plugins using MessageHasBeenPosted (#12539)

The PR introduces a method in helper interface. The method has common code for filtering to be used across plugins which use MessageHasBeenPosted.

plugin/helpers_bots_test.go

@@ -340,3 +340,111 @@ func TestEnsureBot(t *testing.T) {
 		})
 	})
 }
+
+func TestShouldProcessMessage(t *testing.T) {
+	p := &plugin.HelpersImpl{}
+	expectedBotId := model.NewId()
+
+	setupAPI := func() *plugintest.API {
+		return &plugintest.API{}
+	}
+
+	t.Run("should not respond to itself", func(t *testing.T) {
+		api := setupAPI()
+		api.On("KVGet", plugin.BOT_USER_KEY).Return([]byte(expectedBotId), nil)
+		p.API = api
+		shouldProcessMessage, _ := p.ShouldProcessMessage(&model.Post{Type: model.POST_HEADER_CHANGE, UserId: expectedBotId}, plugin.AllowSystemMessages(), plugin.AllowBots())
+
+		assert.False(t, shouldProcessMessage)
+	})
+
+	t.Run("should not process as the post is generated by system", func(t *testing.T) {
+		shouldProcessMessage, _ := p.ShouldProcessMessage(&model.Post{Type: model.POST_HEADER_CHANGE})
+
+		assert.False(t, shouldProcessMessage)
+	})
+
+	t.Run("should not process as the post is sent to another channel", func(t *testing.T) {
+		channelID := "channel-id"
+		api := setupAPI()
+		api.On("GetChannel", channelID).Return(&model.Channel{Id: channelID, Type: model.CHANNEL_GROUP}, nil)
+		p.API = api
+		api.On("KVGet", plugin.BOT_USER_KEY).Return([]byte(expectedBotId), nil)
+
+		shouldProcessMessage, _ := p.ShouldProcessMessage(&model.Post{ChannelId: channelID}, plugin.AllowSystemMessages(), plugin.AllowBots(), plugin.FilterChannelIDs([]string{"another-channel-id"}))
+
+		assert.False(t, shouldProcessMessage)
+	})
+
+	t.Run("should not process as the post is created by bot", func(t *testing.T) {
+		userID := "user-id"
+		channelID := "1"
+		api := setupAPI()
+		p.API = api
+		api.On("GetUser", userID).Return(&model.User{IsBot: true}, nil)
+		api.On("KVGet", plugin.BOT_USER_KEY).Return([]byte(expectedBotId), nil)
+
+		shouldProcessMessage, _ := p.ShouldProcessMessage(&model.Post{UserId: userID, ChannelId: channelID},
+			plugin.AllowSystemMessages(), plugin.FilterUserIDs([]string{"another-user-id"}))
+
+		assert.False(t, shouldProcessMessage)
+	})
+
+	t.Run("should not process the message as the post is not in bot dm channel", func(t *testing.T) {
+		userID := "user-id"
+		channelID := "1"
+		channel := model.Channel{
+			Name: "user1__" + expectedBotId,
+			Type: model.CHANNEL_OPEN,
+		}
+		api := setupAPI()
+		api.On("GetChannel", channelID).Return(&channel, nil)
+		api.On("KVGet", plugin.BOT_USER_KEY).Return([]byte(expectedBotId), nil)
+		p.API = api
+
+		shouldProcessMessage, _ := p.ShouldProcessMessage(&model.Post{UserId: userID, ChannelId: channelID}, plugin.AllowSystemMessages(), plugin.AllowBots(), plugin.OnlyBotDMs())
+
+		assert.False(t, shouldProcessMessage)
+	})
+
+	t.Run("should process the message", func(t *testing.T) {
+		channelID := "1"
+		api := setupAPI()
+		api.On("KVGet", plugin.BOT_USER_KEY).Return([]byte(expectedBotId), nil)
+		p.API = api
+
+		shouldProcessMessage, _ := p.ShouldProcessMessage(&model.Post{UserId: "1", Type: model.POST_HEADER_CHANGE, ChannelId: channelID},
+			plugin.AllowSystemMessages(), plugin.FilterChannelIDs([]string{channelID}), plugin.AllowBots(), plugin.FilterUserIDs([]string{"1"}))
+
+		assert.True(t, shouldProcessMessage)
+	})
+
+	t.Run("should process the message for plugin without a bot", func(t *testing.T) {
+		channelID := "1"
+		api := setupAPI()
+		api.On("KVGet", plugin.BOT_USER_KEY).Return(nil, nil)
+		p.API = api
+
+		shouldProcessMessage, _ := p.ShouldProcessMessage(&model.Post{UserId: "1", Type: model.POST_HEADER_CHANGE, ChannelId: channelID},
+			plugin.AllowSystemMessages(), plugin.FilterChannelIDs([]string{channelID}), plugin.AllowBots(), plugin.FilterUserIDs([]string{"1"}))
+
+		assert.True(t, shouldProcessMessage)
+	})
+
+	t.Run("should process the message when filter channel and filter users list is empty", func(t *testing.T) {
+		channelID := "1"
+		api := setupAPI()
+		channel := model.Channel{
+			Name: "user1__" + expectedBotId,
+			Type: model.CHANNEL_DIRECT,
+		}
+		api.On("GetChannel", channelID).Return(&channel, nil)
+		api.On("KVGet", plugin.BOT_USER_KEY).Return([]byte(expectedBotId), nil)
+		p.API = api
+
+		shouldProcessMessage, _ := p.ShouldProcessMessage(&model.Post{UserId: "1", Type: model.POST_HEADER_CHANGE, ChannelId: channelID},
+			plugin.AllowSystemMessages(), plugin.AllowBots())
+
+		assert.True(t, shouldProcessMessage)
+	})
+}