# Migrating from shinytest

`{shinytest2}` is the successor to `{shinytest}`. `{shinytest}` was implemented using `{webdriver}` which uses PhantomJS. PhantomJS has been unsupported since 2017 and does not support displaying `{bslib}`’s Bootstrap v5. `{shinytest2}` uses `{chromote}` to connect to your locally installed Chrome or Chromium application, allowing `{shinytest2}` to display `{bslib}`’s Bootstrap v5.

To auto-migrate your existing `{shinytest}` tests to `{shinytest2}`, call `shinytest2::migrate_from_shinytest(PATH_TO_APP)`.

# Code structure

In the sub sections below, `ShinyDriver` is a reference to the `shinytest::ShinyDriver` R6 object. In each code block, the `ShinyDriver` object will be referred to as `old`. Similarly, `AppDriver` is a reference to `shinytest2::AppDriver` R6 object. `shinytest2::AppDriver` has replaced `{shinytest}`’s `ShinyDriver` object and will be referred to as `new` in each code block.

## Methods

### `ShinyDriver$click()`

Signature: `ShinyDriver$click(name, iotype = c("auto", "input", "output"))`

The parameters have been separated to be clearer in their intended use to `AppDriver$click(input, output, ..., selector)`.

    ## {shinytest}
    old$click("mybutton")
    old$click("clickcount", iotype = "output")
    old$click("my_id", iotype = "auto")

    ## {shinytest2}
    new$click("mybutton"); new$click(input = "mybutton")
    new$click(output = "clickcount")
    new$click(selector = "#my_id")

### `ShinyDriver$executeScript()`

Signature: `ShinyDriver$executeScript(script, ...)`

The `...` must now be inserted into the script. You can do this with commands like `glue::glue()` or `paste()`. Extra parameters include `file`, which can contain your `script` content, and `timeout`, which will throw an error if the `timeout` (in milliseconds) is reached before the script returns. If a promise is the last value in the `script` then the `resolve`d value will be sent back to the R session.

    ## {shinytest}
    life <- 42
    old$executeScript("1 + 1;")
    old$executeScript("var life = arguments[0]; life;", life)

    ## {shinytest2}
    life <- 42
    new$get_js("1 + 1;")
    new$get_js(paste0("let life = ", jsonlite::toJSON(life, auto_unbox = TRUE), "; life;"))
    # If a promise is returned, the resolved value will be sent back to the R session
    new$get_js(
      paset0("
      let life = ", jsonlite::toJSON(life, auto_unbox = TRUE), ";
      new Promise((resolve, reject) => resolve(life));
      ")
    )

### `ShinyDriver$executeScriptAsync()`

Signature: `ShinyDriver$executeScriptAsync(script, ...)`

`ShinyDriver$executeScriptAsync()` magically made a `callback` argument available in the JavaScript code and would block the R session until `callback` was called within `script`. In `shinytest2` your script will need to be updated to use a JavaScript `Promise.` The `Promise`’s `resolve` method should be the callback that you used previously. You should also provide a maximum `timeout` (in milliseconds) that you are willing to wait before an error is thrown. For example:

    ## {shinytest}
    # Wait until a button is clicked
    old$executeScriptAsync(
      '
      var selector = arguments[0];
      var callback = arguments[1];
      $( selector ).one( "click", function() {
        callback();
      });
      ',
      "#mybutton"
    )

    ## {shinytest2}
    # Wait until a button is clicked
    new$get_js(
      paste0("
      let selector = ", jsonlite::toJSON("#mybutton", auto_unbox = TRUE), ";
      new Promise((resolve, reject) => {
        $( selector ).one( \"click\", function() {
          resolve();
        });
      });
      "),
      timeout = 15 * 1000
    )

### `ShinyDriver$getAllValues()`

Signature: `ShinyDriver$getAllValues(input = TRUE, output = TRUE, export = TRUE)`

This method has been renamed to `AppDriver$get_values(..., input, output, export, hash_images = TRUE)`. The new method has a slightly different behavior if only some of the `input`, `output` or `export` arguments are provided. If `input`, `output` or `export` are provided, then the method will return the values for the provided `input`, `output` or `export` names only. If no `input`, `output` or `export` are provided, then the method will return all values, similar to setting `ShinyDriver$getAllValues(input = TRUE, output = TRUE, export = TRUE)`.

    ## {shinytest}
    old$getAllValues()
    # All input values
    old$getAllValues(input = TRUE, output = FALSE, export = FALSE)
    # Only `clickcount` output value
    old$getAllValues(input = FALSE, output = "clickcount", export = FALSE)

    ## {shinytest2}
    new$get_values()
    # All input values
    new$get_values(input = TRUE)
    # Only `clickcount` output value
    new$get_values(output = "clickcount")

### `ShinyDriver$getValue()`

Signature: `ShinyDriver$getValue(name, iotype = c("auto", "input", "output"))`

This method has been renamed to `AppDriver$get_value(..., input, output, export)` and its parameters have been spread out into `input` and `output`, while adding support for `export`.

    ## {shinytest}
    old$getValue("myinput")

    ## {shinytest2}
    new$get_value(input = "myinput")
    # Equivalent to
    new$get_values(input = "myinput")$input$myinput

### `ShinyDriver$getUrl()`

Signature: `ShinyDriver$getUrl()`

This method has been renamed to `AppDriver$get_url()`.

    ## {shinytest}
    old$getUrl()

    ## {shinytest2}
    new$get_url()

### `ShinyDriver$setInputs()`

Signature: `ShinyDriver$setInputs(..., wait_ = TRUE, values_ = TRUE, timeout_ = 3 * 1000, allowInputNoBinding_ = FALSE, priority_ = c("input", "event"))`

The method name has been renamed to `AppDriver$get_values()` and the parameters have been converted to `snake_case`. `value_` support has been removed, but the same functionality can be achieved via a call to `AppDriver$get_values()` after a call to `AppDriver$set_inputs()`.

    ## {shinytest}
    getValuesResult <- old$setInputs(life = 42)

    ## {shinytest2}
    new$set_inputs(life = 42)
    get_values_result <- new$get_values()

### `ShinyDriver$getWindowSize()`, `ShinyDriver$setWindowSize()`

Signatures: * `ShinyDriver$getWindowSize()` * `ShinyDriver$setWindowSize(width, height)`

These methods have been renamed to `AppDriver$get_window_size()` and `AppDriver$set_window_size(width, height)` respectively.

    ## {shinytest}
    old$getWindowSize()
    old$setWindowSize(width = 1024, height = 768)

    ## {shinytest2}
    new$get_window_size()
    new$set_window_size(width = 1024, height = 768)

### `ShinyDriver$checkUniqueWidgetNames()`

Signature: `ShinyDriver$checkUniqueWidgetNames()`

This method checks to make sure all input and output names are unique. It is still run at initialization via `AppDriver$new(check_names = TRUE)`, and if any issues are found during startup, only warnings will be displayed. The exported method has been upgraded to an expectation version and renamed to `AppDriver$expect_unique_names()`.

    ## {shinytest}
    old$checkUniqueWidgetNames()

    ## {shinytest2}
    new$expect_unique_names()

## Snapshots

Snapshots are now handled by `{testthat}`. To leverage this capability, use the `AppDriver$expect_*()` methods to assert that the value is consistent over many testing executions.

### `ShinyDriver$snapshotInit()`

Signature: `ShinyDriver$snapshotInit(path, screenshot = TRUE)`

This method has been moved to the parameters: `AppDriver$new(name = path)`. Screenshots via `{testthat}` snapshots are not allowed until an `AppDriver$new(variant=)` value is provided. `variant` is similar to the `suffix` value in `shinytest::testApp(suffix=)`.

    ## {shinytest}
    old$snapshotInit("mytest")

    ## {shinytest2}
    new <- AppDriver$new(name = "mytest", variant = NULL)
    # Suggested
    new <- AppDriver$new(name = "mytest", variant = platform_variant())

### `ShinyDriver$snapshot()`

Signature: `ShinyDriver$snapshot(items = NULL, filename = NULL, screenshot = NULL)`

In `{shinytest}` this method would expect a screenshot and expect all values to be consistent. This method no longer exists in `{shinytest2}`, and has been broken up into two methods that must be called independently: `AppDriver$expect_screenshot()` and `AppDriver$expect_values()`. `AppDriver$expect_values()` will (by default) take a debug screenshot that will never fail in an expectation. This allows for a historical record (version control) of what the app looked like while not having to constantly battle with false-positive screenshot failures. If a single `output` value is supplied to `AppDriver$expect_values()`, then the debug screenshot is zoomed in on the output value.

    ## {shinytest}
    old$snapshot()
    old$snapshot(items = list(output = "clickcount"))

    ## {shinytest2}
    # Must supply `variant=` to be able to call `AppDriver$expect_screenshot()`, even if it is `NULL`
    new <- AppDriver$new(path_to_app, variant = NULL)
    new$expect_screenshot(); new$expect_values()
    new$expect_screenshot(); new$expect_values(output = "clickcount")

    # Suggested;
    new <- AppDriver$new(path_to_app)
    new$expect_values()

### `ShinyDriver$takeScreenshot()`

Signature: `ShinyDriver$takeScreenshot(file = NULL, id = NULL, parent = FALSE)`

This method has been renamed to `AppDriver$get_screenshot(file)`, and the `id` and `parent` parameters have been removed. To use a selector, set `AppDriver$get_screenshot(myfile, selector = ".custom-selector")` or `screenshot_args` directly.

    ## {shinytest}
    old$takeScreenshot("myfile1.png")
    old$takeScreenshot("myfile2.png", id = "myid")

    ## {shinytest2}
    new$get_screenshot("myfile1.png")
    new$get_screenshot("myfile2.png", selector = "#myid")
    new$get_screenshot("myfile2.png", screenshot_args = list(selector = "#myid"))

### `ShinyDriver$snapshotDownload()`

Signature: `ShinyDriver$snapshotDownload(id, filename)`

This method has been renamed to `AppDriver$expect_download(id, filename)`.

    ## {shinytest}
    old$snapshotDownload("mylinkid")

    ## {shinytest2}
    new$expect_download("mylinkid")

### `ShinyDriver$stop()`

Signature: `ShinyDriver$stop()`

This method stayed the same! 🥳 In `{shinytest2}`, this will also stop your [`ChromeSession`] instance and clean up any temporary Shiny log files.

### `ShinyDriver$uploadFile()`

Signature: `ShinyDriver$uploadFile(..., wait_ = TRUE, values_ = TRUE, timeout_ = 3 * 1000)`

This method has been renamed to `AppDriver$upload_file(...)`, and similar to `AppDriver$set_inputs()`, support for `ShinyDriver$uploadFile(values_ =)` has been removed.

    ## {shinytest}
    old$uploadFile(myFileInput = "myfile.txt")

    ## {shinytest2}
    new$upload_file(myFileInput = "myfile.txt")

### `ShinyDriver$waitFor()`

Signature: `ShinyDriver$waitFor(expr, checkInterval = 100, timeout = 3000)`

This method has been renamed and had its parameters reordered to `AppDriver$wait_for_js(script, timeout, interval)`. Like other JavaScript methods in `{shinytest2}`, `script` needs to explicitly return a value.

    ## {shinytest}
    old$waitFor("$('#myid').length > 0")

    ## {shinytest2}
    new$wait_for_js("$('#myid').length > 0");

### `ShinyDriver$waitForShiny()`

Signature: `ShinyDriver$waitForShiny()`

This method has been upgraded to `AppDriver$wait_for_idle(duration = 500, timeout = 30 * 1000)`. The `ShinyDriver$waitForShiny()` method only waited until a single instance in time stated that Shiny was no longer busy. The new method will wait until Shiny has been “idle” for a continuous stretch of time. It is useful to wait until Shiny has been idle for a set duration in order to avoid situations where dynamic UI needs to calculate new outputs given new input information.

    ## {shinytest}
    old$waitForShiny()

    ## {shinytest2}
    # Equivalent
    new$wait_for_idle(duration = 0, timeout = 3 * 1000)
    # Suggested (Shiny must become continuously idle for at least 500ms within 30s
    new$wait_for_idle()

### `ShinyDriver$waitForValue()`

Signature: `ShinyDriver$waitForValue(name, ignore = list(NULL, ""), iotype = c("input", "output", "export"), timeout = 10000, checkInterval = 400)`: This (underutilized) method has had the `name`/`iotype` spread out into separate `input`, `output`, `export` parameters. Only one `input`/`output`/`export` value may be supplied in an `AppDriver` object. The `timeout` has been increased to 15 seconds. Both methods still poll the Shiny application at a set `interval` for the corresponding value to be something not in the `ignore`d set of values.

    ## {shinytest}
    old$waitForValue("myslider")
    old$waitForValue("mydynamicplot", iotype = "output")

    ## {shinytest2}
    new$wait_for_value("myslider"); new$wait_for_value(input = "myslider")
    new$wait_for_value(output = "mydynamicplot")

## Elements / Widgets

Direct element or Widget support for `{shinytest2}` has been drastically reduced. With the ability to execute any JavaScript function via `$get_js(script)` and `$run_js(script)`, it is now possible to reproduce many of the methods that were provided in `{shinytest}`.

### `ShinyDriver$findElement()`, `ShinyDriver$findElements()`, `ShinyDriver$findWidget()`

Signatures: * `ShinyDriver$findElement(css = NULL, linkText = NULL, partialLinkText = NULL, xpath = NULL)` * `ShinyDriver$findElements(css = NULL, linkText = NULL, partialLinkText = NULL, xpath = NULL)` * `ShinyDriver$findWidget(name, iotype = c("auto", "input", "output"))`

These methods have been removed. It is suggested to use JavaScript code directly or use newer helper methods.

    ## {shinytest}
    old$findElement("#mybutton")$click()
    old$findElement("#mybutton")$getText()
    old$findElement("#mybutton")$getCssValue("color")

    ## {shinytest2}
    new$get_text(selector = "#mybutton")
    new$click(selector = "#mybutton")
    # No direct equivalent method. Using JavaScript instead
    new$get_js('$("#mybutton").css("color")')

### `ShinyDriver$getSource()`, `ShinyDriver$getTitle()`

Signatures: * `ShinyDriver$getSource()` * `ShinyDriver$getTitle()`

These methods have been removed. It is suggested to use JavaScript code directly, or to use newer helper methods.

    ## {shinytest}
    old$getSource()
    old$getTitle()

    ## {shinytest2}
    new$get_html("html", outer_html = TRUE)
    new$get_js("window.document.title;")

## Testing setup

`{shinytest2}` is heavily integrated with the `{testthat}` testing framework. Similar to `{shinytest}`, snapshots are recorded, but they are recorded via `{testthat}` snapshots. For more information on the robustness of different testing approaches, please see the Robust testing vignette.

- `ShinyDriver$new(suffix=)`: Please use `AppDriver$new(variant=)`.

    ## {shinytest}
    old <- ShinyDriver$new(path_to_app, suffix = "macos-4.1")

    ## {shinytest2}
    new <- AppDriver$new(path_to_app, variant = "macos-4.1")

### `ShinyDriver$getRelativePathToApp()`, `ShinyDriver$getTestsDir()`

Signatures: * `ShinyDriver$getRelativePathToApp()` * `ShinyDriver$getTestsDir()`

These methods have been removed as they are no longer needed given execution `{shinytest2}` testing is always done within the `{testthat}` testing framework.

### `ShinyDriver$getSnapshotDir()`

Signature: `ShinyDriver$getSnapshotDir()`

This method has been removed as `{testthat}` uses the `./_snaps` directory to store snapshot outputs.

### `ShinyDriver$expectUpdate()`

Signature: `ShinyDriver$expectUpdate(output, ..., timeout = 3000, iotype = c("auto", "input", "output"))`

This method is no longer supported. While knowing that an output value has been updated, it is very uncertain as to what the new value is. While possibly useful, it is not robust and therefore not recommended. Other testing methods should be explored.

Equivalent code has been provided below for legacy support.

    ## {shinytest}
    old$expectUpdate("myoutput", myinput = 42)

    ## {shinytest2} (equivalent code)
    myoutput_prior <- new$get_values(output = "myoutput")
    new$set_inputs(myinput = 42)
    testthat::expect_failure(
      testthat::expect_equal(
        new$get_values(output = "myoutput"),
        myoutput_prior
      )
    )

## Debugging

Debugging in `{shinytest2}` has been unified and is enabled at all times. The `{shinytest}` debugging methods have been removed in favor of `AppDriver$get_logs()`, which returns a similarly shaped `tibble` as `ShinyDriver$getDebugLog()`’s `data.frame`. The columns have been altered to be more generic, where `type` has been broken into two columns: `location` and `level`.

- `ShinyDriver$getDebugLog()`, `ShinyDriver$getEventLog()`: Now use `AppDriver$get_logs()`.
- `ShinyDriver$logEvent(event, ...)`: Messages can still be recorded using `AppDriver$log_message(text)`, but `...` values are no longer supported.
- `ShinyDriver$enableDebugLogMessages(enable = TRUE)`: No longer used. All messages are always recorded.

    ## {shinytest}
    old$getDebugLog(); old$getEventLog()
    old$logEvent("Creating report")

    ## {shinytest2}
    new$get_logs()
    old$log_message("Creating report")

If `options = list(shiny.trace = TRUE)` is set when initializing an `AppDriver` object, then all WebSocket traffic will be recorded.

    ## {shinytest2}
    # Record all websocket traffic. Caution!! This is very verbose!!
    new <- AppDriver$new(path_to_app, options = list(shiny.trace = TRUE))
    new$get_logs()

## Other removed methods

- `ShinyDriver$setValue(name, value, iotype)`: To set an output value, it must be performed by setting an input value and having your render methods set the output value. To set an input value, use `AppDriver$set_inputs()`.

    ## {shinytest}
    old$setValue("myinput", 42)

    ## {shinytest2}
    new$set_inputs(myinput = 42)

- `ShinyDriver$listWidgets()`: This method has been removed and can be achieved by getting the names of the existing values: `AppDriver$get_values()`.

    ## {shinytest}
    old$listWidgets()

    ## {shinytest2}
    lapply(new$get_values(), names)

- `ShinyDriver$clone()`: `AppDriver` does not support cloning. (The underlying `ChromoteSession` does not support cloning, so `AppDriver` cannot support cloning.)

- `ShinyDriver$goBack()`, `ShinyDriver$refresh()`: These methods have been removed, but can be achieved with `AppDriver$run_js(script)`.

    ## {shinytest}
    old$goBack()
    old$refresh()

    ## {shinytest2}
    # Go back
    new$run_js("window.history.back();")
    # Refresh page
    new$run_js("window.location.reload();")

- `ShinyDriver$getAppDir()`, `ShinyDriver$getAppFilename()`, `ShinyDriver$isRmd()`: `AppDriver$get_dir()` is the only method still supported given `AppDriver$new(app_dir=)` is a single directory path. The other methods have been removed as their functionality does not make sense within `{shinytest2}`.

    ## {shinytest}
    old$isRmd()
    old$getAppDir()
    old$getAppFilename()

    ## {shinytest2}
    app_dir <- new$get_dir()
    rmd_files <- fs::dir_ls(new$get_dir(), regexp = "\\.[Rr]md$")
    is_rmd <- length(rmd_files) >= 1
    app_filename <- if (has_rmd) fs::path_file(rmd_files[1]) else NULL

- `ShinyDriver$sendKeys(name, keys)`: This method has been removed and there is currently no easy alternative. If you are familiar with the key code values, you can trigger them with `jQuery` and `AppDriver$run_js(script)`.

    ## {shinytest}
    old$sendKeys("myinput", webdriver::keys$enter)

    ## {shinytest2}
    new$run_js("$('#myinput').trigger({type: 'keypress', which: 13, keyCode: 13});")