Test case for writing min/max for DATEs

tests/testthat/_snaps/write-parquet-statistics.md

@@ -86,3 +86,25 @@
   68 5 2 08, 00, .... 08, 00, ....
   81 6 2 08, 00, .... 08, 00, ....
 
+# min/max for DATEs
+
+ Code
+  as.data.frame(read_parquet_schema(tmp)[, -1])
+ Output
+  name r_type type type_length repetition_type converted_type logical_type
+  1 schema <NA> <NA> NA <NA> <NA> 
+  2 day Date INT32 NA REQUIRED DATE DATE
+  3 count integer INT32 NA REQUIRED INT_32 INT, 32,....
+  num_children scale precision field_id
+  1 2 NA NA NA
+  2 NA NA NA NA
+  3 NA NA NA NA
+ Code
+  as.Date(map_int(minv, readBin, what = "integer", n = 1))
+ Output
+  [1] "2024-09-06" "2024-09-08" "2024-09-10" "2024-09-12" "2024-09-14"
+ Code
+  as.Date(map_int(maxv, readBin, what = "integer", n = 1))
+ Output
+  [1] "2024-09-07" "2024-09-09" "2024-09-11" "2024-09-13" "2024-09-15"
+

tests/testthat/test-write-parquet-statistics.R

@@ -45,3 +45,26 @@ test_that("min/max for integers", {
  mtd[mtd$column == 2, c("row_group", "column", "min_value", "max_value")]
  )
 })
+
+test_that("min/max for DATEs", {
+ tmp <- tempfile(fileext = ".parquet")
+ on.exit(unlink(tmp), add = TRUE)
+
+ df <- data.frame(
+ day = rep(as.Date("2024-09-16") - 10:1, each = 10),
+ count = 1:100
+ )
+ write_parquet(
+ df, tmp,
+ options = parquet_options(num_rows_per_row_group = 20)
+ )
+ expect_equal(as.data.frame(df), as.data.frame(read_parquet(tmp)))
+ mtd <- as.data.frame(read_parquet_metadata(tmp)[["column_chunks"]])
+ minv <- mtd[mtd$column == 0, "min_value"]
+ maxv <- mtd[mtd$column == 0, "max_value"]
+ expect_snapshot({
+ as.data.frame(read_parquet_schema(tmp)[,-1])
+ as.Date(map_int(minv, readBin, what = "integer", n = 1))
+ as.Date(map_int(maxv, readBin, what = "integer", n = 1))
+ })
+})