Package 'shinytesters'

Title: Update 'Shiny' Inputs when using testServer()
Description: Create mocked bindings to 'Shiny' update functions within test function calls to automatically update input values. The mocked bindings simulate the communication between the server and UI components of a 'Shiny' module in testServer().
Authors: Ashley Baldry [aut, cre]
Maintainer: Ashley Baldry <[email protected]>
License: GPL-3
Version: 0.1.0
Built: 2026-05-24 09:18:07 UTC
Source: https://github.com/ashbaldry/shinytesters

Help Index

Create Test Update Functions

Description

Given a set of functions from an R package, create a set of mocked functions that can be used as bindings to test UI updates within testServer.

Usage

create_test_update_fns(
  fn_names,
  id_arg = "inputId",
  value_args = c("value", "selected"),
  range_value_args = c("start", "end"),
  .package = "shiny"
)

Arguments

fn_names

A character vector (string) of function names to create wrappers for
id_arg

A character string of the argument in 'fn_names' that relates to the HTML ID argument. Default is "inputId"
value_args

A character vector of the arguments in 'fn_names' that relate to the input value arguments. Defaults are '"value"' and '"selected'.
range_value_args

A character vector of the arguments in 'fn_names' that relate to the input value arguments when multiple arguments can be used to update the input. Defaults are '"start"' and '"end"'.
.package

Character string of the package that 'fn_names' exist in. Default is '"shiny"'

Value

A named list of function expressions, one for each function supplied in 'fn_names'.

Examples

create_test_update_fns(
  c("updateSelectInput", "updateTextInput"),
  .package = "shiny"
)

Use Shiny Testers

Description

Enable 'update' functions in the Shiny or Shiny extension package to be mocked in tests.

Usage

use_shiny_testers(..., .package = "shiny", .env = rlang::caller_env())

with_shiny_testers(code, ..., .package = "shiny")

Arguments

...

Arguments passed to create_test_update_fns
.package

Character string of the package that the update functions exist in. Default is '"shiny"'
.env

Environment that defines effect scope. For expert use only.
code

Code to execute with specified bindings.

Value

Implicit return of the updated functions in the supplied package within the specified environment.

Examples

library(shiny)
library(testthat)

example_server_fn <- function(input, output, session) {
  observeEvent(input$trigger, {
      updateTextInput(
      inputId = "result",
      label = "New Label",
      value = NULL,
      placeholder = "New placeholder"
    )
  })
}

test_that("Check that text input gets updated", {
  use_shiny_testers()

  shiny::testServer(
    app = example_server_fn,
    expr = {
      session$setInputs(result = "Example text")
      session$setInputs(trigger = 1L)

      expect_identical(input$result, "Example text")
      expect_identical(input$result.label, "New Label")
      expect_identical(input$result.placeholder, "New placeholder")
    }
  )
})