adds test related to flow_from_dataset

Author: dfalbel

R/preprocessing.R

@@ -893,7 +893,7 @@ flow_images_from_directory <- function(
 #' @family image preprocessing
 #' @export
 flow_images_from_dataframe <- function(
-  dataframe, directory=NULL, x_col="filename", y_col="class",
+  dataframe, directory = NULL, x_col = "filename", y_col = "class",
   generator = image_data_generator(), target_size = c(256,256), 
   color_mode = "rgb", classes = NULL, class_mode = "categorical", 
   batch_size = 32, shuffle = TRUE, seed = NULL, save_to_dir = NULL, 

tests/testthat/test-preprocessing.R

@@ -75,5 +75,29 @@ test_succeeds("images arrays can be resized", {
   }
 })
 
+test_succeeds("flow images from dataframe works", {
+  if (have_pillow()) {
+    
+    df <- data.frame(
+      fname = rep("digit.jpeg", 10), 
+      class = letters[1:10], 
+      stringsAsFactors = FALSE
+      )
+    img_gen <- flow_images_from_dataframe(
+      df, 
+      directory = ".", 
+      x_col = "fname", 
+      y_col = "class", 
+      drop_duplicates = FALSE
+      )
+    
+    batch <- reticulate::iter_next(img_gen)
+    
+    expect_equal(dim(batch[[1]]), c(10, 256, 256, 3))
+    expect_equal(dim(batch[[2]]), c(10, 10))
+  }
+})
+
+