adding test for new function normalise_pop_size()

R/plotting.R

@@ -101,7 +101,7 @@ normalise_pop_size <- function(pop) {
 
     pop_norm <- pop |> dplyr::left_join(pop_max, by = "region") |>
         dplyr::mutate(pop_max = .data$pop_size / .data$pop_max) |>
-        dplyr::rename(pop_rel = .data$pop_max)
+        dplyr::rename(pop_rel = "pop_max")
 
     return(pop_norm)
 }

tests/testthat/test-normalise_pop_size.R

@@ -0,0 +1,46 @@
+test_that("normalise_pop_size works correctly", {
+
+    ## single region, constant pop_size through all ages and years:
+    age_min <- 0
+    age_max <- 5
+    pop <- popim_population(region = "UK", year_min = 2000, year_max = 2004,
+                            age_min = age_min, age_max = age_max)
+    pop$pop_size <- 1
+
+    rel_size_exp <- rep(1/(age_max - age_min + 1), nrow(pop))
+    expect_equal(normalise_pop_size(pop)$pop_rel, rel_size_exp)
+
+    ## population size varying through the years:
+    age_min <- 0
+    age_max <- 4
+    pop <- popim_population(region = "UK", year_min = 2000, year_max = 2002,
+                            age_min = age_min, age_max = age_max)
+
+    pop$pop_size <- pop$cohort - 1990
+
+    pop_tot <- pop |> dplyr::group_by(.data$year) |>
+        dplyr::summarise(tot = sum(.data$pop_size))
+    pop_rel <- pop$pop_size / max(pop_tot$tot)
+
+    expect_equal(pop_rel,
+                 normalise_pop_size(pop)$pop_rel)
+
+    ## setting up a 2-region population:
+    pop2 <- pop
+    pop2$region <- "FRA"
+    pop2$pop_size <- pop2$pop_size * 2 ## double the population size,
+                                       ## but the age structure is
+                                       ## still the same, so relative
+                                       ## population size will be the
+                                       ## same.
+
+    pop2_tot <- pop2 |> dplyr::group_by(.data$year) |>
+        dplyr::summarise(tot = sum(.data$pop_size))
+
+    pop_agg <- rbind(pop, pop2)
+    pop_rel_agg <- c(pop_rel, pop_rel)
+
+    expect_equal(pop_rel_agg,
+                 normalise_pop_size(pop_agg)$pop_rel)
+
+})