Fix aes_string() deprecation warning in diagnostics plots (#582)

R/plot_model_diagnostics.R

@@ -37,7 +37,7 @@ plot.model_diagnostics <- function(x, ..., variable = "y_hat", yvariable = "resi
   class(all_models) <- "data.frame"
   nlabels <- length(unique(all_models$label))
 
-   pl <- ggplot(all_models, aes_string(x = variable, y = yvariable, color = "label", group = "label")) +
+   pl <- ggplot(all_models, aes(x = .data[[variable]], y = .data[[yvariable]], color = .data[["label"]], group = .data[["label"]])) +
     geom_point(size = 0.1) +
     theme_default_dalex() +
     scale_color_manual(name = "Model", values = colors_discrete_drwhy(nlabels))

R/plot_predict_diagnostics.R

@@ -39,7 +39,7 @@ plot.predict_diagnostics <- function(x, ...) {
     statistic <- x$test$statistic
     cut_points <- x$cut_points
 
-    pl <- ggplot(df, aes_string("Var1", "Freq", fill = "direction")) +
+    pl <- ggplot(df, aes(x = .data[["Var1"]], y = .data[["Freq"]], fill = .data[["direction"]])) +
       geom_col() +
       scale_y_continuous("") +
       scale_x_discrete("residuals", labels = as.character(cut_points)) +

tests/testthat/test_model_diagnostics.R

@@ -49,6 +49,25 @@ test_that("Print",{
   expect_error(print(diag_ranger_3), NA)
 })
 
+test_that("Plot does not use deprecated aes_string() (#582)", {
+  # ggplot2 >= 3.0.0 hard-deprecates aes_string(); plot.model_diagnostics()
+  # used to call it directly, which raised a `lifecycle::deprecate_warn()`
+  # every time a diagnostics plot was drawn (see reprex in issue #582).
+  #
+  # We check this structurally (source no longer references aes_string())
+  # rather than by capturing the warning at call time, because lifecycle
+  # warnings are only emitted once per R session: whichever test runs
+  # plot.model_diagnostics() first "uses up" the warning for the rest of
+  # the session/suite, which would make a warning-capturing test silently
+  # pass regardless of whether the bug is actually fixed.
+  plot_fun_src <- deparse(body(getS3method("plot", "model_diagnostics")))
+  expect_false(any(grepl("aes_string", plot_fun_src, fixed = TRUE)))
+
+  # the plot itself must still work and produce a ggplot object
+  expect_is(plot(diag_ranger_1), "gg")
+  expect_is(plot(diag_ranger_1, diag_lm, variable = "construction.year"), "gg")
+})
+
 explainer_array <- explainer_ranger
 explainer_array$y_hat <- as.array(explainer_array$y_hat)
 

tests/testthat/test_predict_diagnostics.R

@@ -21,6 +21,19 @@ test_that("Output format - plot",{
   expect_is(plot(lm_rd), "gg")
 })
 
+test_that("Plot does not use deprecated aes_string() (#582)", {
+  # Same root cause as plot.model_diagnostics(): the histogram branch of
+  # plot.predict_diagnostics() (used when variables = NULL) also called the
+  # deprecated aes_string(). See test_model_diagnostics.R for why this is
+  # checked structurally instead of via expect_no_warning() (lifecycle
+  # deprecation warnings only fire once per R session).
+  plot_fun_src <- deparse(body(getS3method("plot", "predict_diagnostics")))
+  expect_false(any(grepl("aes_string", plot_fun_src, fixed = TRUE)))
+
+  ranger_rd_hist <- predict_diagnostics(explainer_classif_ranger, new_observation = titanic_imputed[1, -8], variables = NULL)
+  expect_is(plot(ranger_rd_hist), "gg")
+})
+
 
 #:# alias