Change default value for strategy in $n_chunks() (#1137)

NEWS.md

@@ -2,6 +2,10 @@
 
 ## Polars R Package (development version)
 
+### Breaking changes
+
+- In `$n_chunks()`, the default value of `strategy` now is `"first"` (#1137).
+
 ### New features
 
 - New method `$has_nulls()` (#1133).

R/dataframe__frame.R

@@ -1215,7 +1215,7 @@ DataFrame_first = function() {
 #' str(z)
 #' z = rechunk(z)
 #' str(z)
-DataFrame_n_chunks = function(strategy = "all") {
+DataFrame_n_chunks = function(strategy = "first") {
   .pr$DataFrame$n_chunks(self, strategy) |>
     unwrap("in n_chunks():")
 }

tests/testthat/test-concat.R

@@ -58,8 +58,8 @@ test_that("concat dataframe", {
   )
 
   # check rechunk works
-  expect_identical(pl$concat(mtcars, mtcars, rechunk = TRUE)$n_chunks(), rep(1, 11))
-  expect_identical(pl$concat(mtcars, mtcars, rechunk = FALSE)$n_chunks(), rep(2, 11))
+  expect_identical(pl$concat(mtcars, mtcars, rechunk = TRUE)$n_chunks("all"), rep(1, 11))
+  expect_identical(pl$concat(mtcars, mtcars, rechunk = FALSE)$n_chunks("all"), rep(2, 11))
 
 
 

tests/testthat/test-dataframe.R

@@ -948,15 +948,15 @@ test_that("n_chunks", {
     how = "horizontal"
   )
 
-  expect_identical(df$n_chunks(), c(1, 2))
-  expect_identical(df$n_chunks("first"), c(1))
+  expect_identical(df$n_chunks("all"), c(1, 2))
+  expect_identical(df$n_chunks(), 1)
+  expect_identical(pl$DataFrame()$n_chunks("all"), numeric())
   expect_identical(pl$DataFrame()$n_chunks(), numeric())
-  expect_identical(pl$DataFrame()$n_chunks("first"), numeric())
 
-  pl$DataFrame()$n_chunks("wrong strat") |>
-    get_err_ctx("Plain") |>
-    grepl(pat = "strategy") |>
-    expect_true()
+  expect_grepl_error(
+    pl$DataFrame()$n_chunks("wrong strat"),
+    "strategy not recognized"
+  )
 })