Add snapshot unit tests for plotLongitudinal()

- generated new snapshots for all plots, after modifications made to
  plotting `color.by` default
- generated snapshots for skipped tests

tests/testthat/helper.R

@@ -17,10 +17,8 @@ expect_snapshot_plot <- function(code, name, ...) {
   # unexpectedly fails or skips, testthat will not auto-delete the
   # corresponding snapshot file
   announce_snapshot_file(name = name)
-  # Will skip if run outside of SLIDE (linux), this is necessary due to
-  # minor changes in plotting defaults across OSs that cause
-  # snapshot testing to fail
-  skip_on_os(c("mac", "windows"))   # do we still want to skip this?
+  # only run on MacOS
+  skip_on_os(c("linux", "windows"))
   path <- save_png(code, ...)
   expect_snapshot_file(path, name)
 }

tests/testthat/test-plotLongitudinal.R

@@ -0,0 +1,111 @@
+# Setup -----
+fct_vec <- factor(c("baseline", "6 months", "12 months", "24 months"))
+levels(fct_vec) <- fct_vec
+
+df <- withr::with_seed(100,
+  data.frame(
+    sample_id   = rep(1:10L, times = 4L),
+    pop         = rep_len(utils::head(LETTERS, 10L), 40L),
+    time_point  = rep(fct_vec, each = 10L),
+    seq.1234.56 = stats::rnorm(40, mean = 25, sd = 3.5)
+  )
+)
+
+# Map 'time_point' (chr) to 'time_dbl' (numeric)
+df <- df |>
+ dplyr::left_join(
+   data.frame(time_point = fct_vec, time_dbl = c(0, 6, 12, 24)),
+   by = "time_point"
+ ) |>
+ # code 'size' to correlate with IDs
+ dplyr::mutate(size = dplyr::case_when(sample_id <= 4 ~ "small",
+                                        sample_id > 7 ~ "large",
+                                                 TRUE ~ "medium"))
+
+# Testing ------
+test_that("`plotLongitudinal()` defaults produce the expected plot", {
+  expect_snapshot_plot(
+    plotLongitudinal(df, y = "seq.1234.56", time = "time_point", id = "sample_id"),
+    "plotLongitudinal-defaults"
+  )
+})
+
+
+test_that("`plotLongitudinal()` colors can be specified with `color.by` argument", {
+  expect_snapshot_plot(
+    plotLongitudinal(df, y = "seq.1234.56", time = "time_point",
+                     id = "sample_id", color.by = "size"),
+    "plotLongitudinal-color-by"
+  )
+})
+
+test_that("`plotLongitudinal()` time numeric variable specification works as expected", {
+  expect_snapshot_plot(
+    plotLongitudinal(df, y = "seq.1234.56", time = "time_dbl", id = "sample_id"),
+    "plotLongitudinal-time-dbl"
+  )
+})
+
+test_that("`plotLongitudinal()` summary.line types can be specified", {
+  expect_snapshot_plot(
+    plotLongitudinal(df, y = "seq.1234.56", id = "sample_id",
+                     time = "time_point", summary.line = base::mean),
+    "plotLongitudinal-summary-line")
+})
+
+
+test_that("`plotLongitudinal()` summary.line can be suppressed with `summary.line=NULL`", {
+  expect_snapshot_plot(
+    plotLongitudinal(df, y = "seq.1234.56", id = "sample_id",
+                     time = "time_point", summary.line = NULL),
+    "plotLongitudinal-suppress-summary-line"
+  )
+})
+
+test_that("`plotLongitudinal()` summary.line can be fixed with on-the-fly function", {
+  expect_snapshot_plot(
+    plotLongitudinal(df, y = "seq.1234.56", id = "sample_id",
+                     time = "time_point", summary.line = function(x) 20),
+    "plotLongitudinal-fixed-summary-line"
+  )
+})
+
+test_that("`plotLongitudinal()` displays boxplots at time points with `add.box=TRUE`", {
+  expect_snapshot_plot(
+    plotLongitudinal(df, "seq.1234.56", id = "sample_id",
+                     time = "time_point", add.box = TRUE),
+    "plotLongitudinal-addBox-factor"
+  )
+})
+
+test_that("`plotLongitudinal()` can be facetted by a color/grouping variable", {
+  expect_snapshot_plot({
+    plotLongitudinal(df, y = "seq.1234.56", id = "sample_id",
+                     time = "time_dbl", color.by = "size") +
+      ggplot2::facet_wrap(~size)
+  }, "plotLongitudinal-facet-wrap-size")
+})
+
+test_that("`plotLongitudinal()` boxes remain when facetted by a color/grouping variable", {
+  expect_snapshot_plot({
+    plotLongitudinal(df, y = "seq.1234.56", id = "sample_id",
+                     time = "time_point", color.by = "size", add.box = TRUE) +
+      ggplot2::facet_wrap(~size)
+  }, "plotLongitudinal-facet-wrap-boxes")
+})
+
+test_that("`plotLongitudinal()` can accept all unquoted string args", {
+  expect_snapshot_plot(
+    plotLongitudinal(df, y = seq.1234.56, id = sample_id,
+                     time = time_dbl, color.by = size),
+    "plotLongitudinal-unquoted-args"
+  )
+})
+
+test_that("`plotLongitudinal()` can accept a mix of quoted and unquoted strings", {
+  expect_snapshot_plot(
+    plotLongitudinal(df, y = seq.1234.56, id = "sample_id",
+                     time = time_dbl, color.by = "size"),
+    "plotLongitudinal-mix-quote-args"
+  )
+})