Redraw plot once if one reactive value changes but not the other?

Question

I have two reactive values input$code and input$variants and I want to redraw the plot once if any of the following conditions are true.

1. code changes and variants changes
2. code changes and variants does not change
3. code does not change and variants changes

I can't call both input$code and input$variants in renderPlotly or else the plot will get redrawn twice for #1 above.

---

  output$choose_test <- renderUI({
    data_sets <- loadTest()
    selectizeInput(
      'test', 'Test', choices = data_sets$test, selected = data_sets$test[1]
    )
  })

  output$choose_code <- renderUI({
    validate(
      need(input$test, 'Please choose a test.')
    )

    code <- loadCode(input$test)
    selectizeInput(
      'code', 'Code', choices = code$code, selected = code$code[1]
    )
  })

  output$choose_variants <- renderUI({
    validate(
      need(input$test,  'Please choose a test.'),
      need(input$code,   'Please choose a code.')
    )

    dat <- loadVariants(input$test, input$code)

    default_select <- dat$variant[grep('v1|v2', dat$variant)]
    if (identical(default_select, factor(0))) {
      default_select <- dat$variant[1]
    }

    checkboxGroupInput("variants", "Variants",
                        choices  = dat$variant,
                        selected = default_select)
  })

  output$plot1 <- renderPlotly({

    runLocations <- isolate(loadRunsBetweenDates(input$test, input$code, input$variants))

    total_min_df <-
      runLocations %>%
      group_by(change_number, variant) %>%
      summarize(memory = min(memory))

    total_min_df$change_number <- as.numeric(as.character(total_min_df$change_number))

    p <- ggplot(total_min_df,
           aes(x=change_number,
               y=memory,
               group=variant,
               color=variant))+
    geom_point()+
    geom_smooth(se = FALSE)+
    scale_x_continuous(labels = function(n){format(n, scientific = FALSE)})+
    scale_y_continuous(labels = function(n){format(n, scientific = FALSE)})+
    labs(x = "Change Number", y = "Megabytes")

    ggplotly(p)
  })