GH-49237: [R] Deprecate Feather reader and writer by thisisnic · Pull Request #49276 · apache/arrow

thisisnic · 2026-02-13T15:31:25Z

Rationale for this change

Arrow C++ is deprecating the Feather reader/writer (#49231) so we should update the R functions too

What changes are included in this PR?

Updated write_feather to mention in the docs that it's deprecated.
Refactored write_feather() to wrap new function write_ipc_impl() so we can show deprecation warnings on calls to write_feather() only (previously write_ipc_file() called write_feather() and so I didn't wanna add the deprecation warning without this refactor otherwise a call to write_ipc_file() would trigger it erroneously)
Once we eventually remove write_feather() we can remove this extra function
Split read_ipc_file() and read_feather() into separate functions so we can document them differently. Updated the examples to show using read_ipc_file()
Deprecated format = "feather" in open_dataset(), write_dataset(), and FileFormat$create() - now emits deprecation warning recommending format = "ipc" instead
Updated as.character.FileFormat to return "ipc" instead of "feather"
Updated docs and tests to use "ipc" instead of "feather"

Some 🤖 use here, but I decided on what to do.

Are these changes tested?

Yep

Are there any user-facing changes?

Yep - deprecation warning

GitHub Issue: [R] Deprecate Feather reader and writer #49237

github-actions · 2026-02-13T15:31:50Z

⚠️ GitHub issue #49237 has been automatically assigned in GitHub to PR creator.

Copilot

Pull request overview

This PR deprecates Feather-oriented R APIs in favor of Arrow IPC terminology and updates documentation/tests to use read_ipc_file(), write_ipc_file(), and format = "ipc".

Changes:

Adds deprecation warnings for read_feather(), write_feather(), and format = "feather" dataset usage.
Splits IPC file reader/writer documentation from deprecated Feather docs.
Updates tests, examples, snapshots, and generated Rd files to use IPC naming.

Reviewed changes

Copilot reviewed 25 out of 39 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
r/R/feather.R	Refactors Feather/IPc reader-writer APIs and docs.
r/R/ipc-stream.R	Updates IPC stream docs and raw-file serialization path.
r/R/dataset-write.R	Deprecates `format = "feather"` for dataset writes.
r/R/dataset-format.R	Deprecates Feather format alias and returns `ipc` for IPC formats.
r/R/dataset.R	Updates dataset format documentation and display name.
r/R/dataset-factory.R	Updates dataset factory format documentation.
r/R/parquet.R	Updates inherited reader parameter docs.
r/R/record-batch-reader.R	Updates reader docs to reference IPC file APIs.
r/R/record-batch-writer.R	Updates writer docs to reference IPC file APIs.
r/R/extension.R	Updates extension examples to use IPC file APIs.
r/tests/testthat/test-feather.R	Updates Feather tests for deprecation and IPC replacements.
r/tests/testthat/test-dataset.R	Updates dataset IPC tests and adds Feather deprecation coverage.
r/tests/testthat/test-dataset-write.R	Updates dataset write tests and adds Feather deprecation coverage.
r/tests/testthat/test-read-write.R	Replaces Feather roundtrip usage with IPC file APIs.
r/tests/testthat/test-read-record-batch.R	Replaces Feather reader usage with IPC file reader.
r/tests/testthat/test-metadata.R	Replaces Feather metadata roundtrips with IPC roundtrips.
r/tests/testthat/test-s3.R	Updates S3 IPC read/write test naming and APIs.
r/tests/testthat/test-utf.R	Replaces Feather serialization test with IPC file APIs.
r/tests/testthat/test-extension.R	Updates extension roundtrip to use IPC file APIs.
r/tests/testthat/test-dplyr-mutate.R	Updates dataset format usage to IPC.
r/tests/testthat/test-buffer.R	Replaces Feather writer with IPC file writer.
r/tests/testthat/test-backwards-compatibility.R	Reads Feather golden files via IPC file reader.
r/tests/testthat/test-Array.R	Updates timezone roundtrip to use IPC file APIs.
r/tests/testthat/helper-filesystems.R	Updates filesystem IPC read/write tests.
r/tests/testthat/_snaps/dataset-write.md	Updates snapshots for IPC format calls.
r/man/write_ipc_file.Rd	Adds generated docs for `write_ipc_file()`.
r/man/read_ipc_file.Rd	Adds generated docs for `read_ipc_file()`.
r/man/write_feather.Rd	Updates generated docs for deprecated writer.
r/man/read_feather.Rd	Updates generated docs for deprecated reader.
r/man/write_ipc_stream.Rd	Updates IPC stream writer docs.
r/man/read_ipc_stream.Rd	Updates IPC stream reader docs.
r/man/write_to_raw.Rd	Updates raw serialization docs.
r/man/write_dataset.Rd	Updates dataset write format docs.
r/man/open_dataset.Rd	Updates dataset opening format docs.
r/man/FileFormat.Rd	Updates file format docs.
r/man/dataset_factory.Rd	Updates dataset factory docs.
r/man/RecordBatchReader.Rd	Updates reader reference docs.
r/man/RecordBatchWriter.Rd	Updates writer reference docs.
r/man/vctrs_extension_array.Rd	Updates extension example docs.

Files not reviewed (14)

r/man/FileFormat.Rd: Language not supported
r/man/RecordBatchReader.Rd: Language not supported
r/man/RecordBatchWriter.Rd: Language not supported
r/man/dataset_factory.Rd: Language not supported
r/man/open_dataset.Rd: Language not supported
r/man/read_feather.Rd: Language not supported
r/man/read_ipc_file.Rd: Language not supported
r/man/read_ipc_stream.Rd: Language not supported
r/man/vctrs_extension_array.Rd: Language not supported
r/man/write_dataset.Rd: Language not supported
r/man/write_feather.Rd: Language not supported
r/man/write_ipc_file.Rd: Language not supported
r/man/write_ipc_stream.Rd: Language not supported
r/man/write_to_raw.Rd: Language not supported

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jonkeane

A few comments, but this looks good and if CI is happy I think we are ok to merge. I do think we should avoid changing those signatures now and actually have a deprecation cycle in case someone is using them.

### Rationale for this change See #49231. Deprecate the Feather reader/writer and point users to the Arrow IPC file API. ### What changes are included in this PR? `ipc::feather::Reader::Open`, `ipc::feather::WriteTable` and the `WriteProperties` struct marked with `ARROW_DEPRECATED`, pointing users to `ipc::RecordBatchFileReader` and `ipc::MakeFileWriter`. Deprecation warnings supressed at the internal call sites: `feather.cc`, `feather_test.cc`, the R binding `r/src/feather.cpp` (R deprecation is in #49276), and the GLib binding (GLib deprecation is in #49673). ### Are these changes tested? `-Werror` build of arrow-feather-test passes locally. ### Are there any user-facing changes? No functional change, compile-time deprecation warning for `feather::Reader::Open`, `feather::WriteTable` or feather::WriteProperties. * GitHub Issue: #49231 Authored-by: Tadeja Kadunc <tadeja.kadunc@gmail.com> Signed-off-by: Antoine Pitrou <antoine@python.org>

Copilot

Pull request overview

Copilot reviewed 25 out of 39 changed files in this pull request and generated 2 comments.

Files not reviewed (14)

r/man/FileFormat.Rd: Generated file
r/man/RecordBatchReader.Rd: Generated file
r/man/RecordBatchWriter.Rd: Generated file
r/man/dataset_factory.Rd: Generated file
r/man/open_dataset.Rd: Generated file
r/man/read_feather.Rd: Generated file
r/man/read_ipc_file.Rd: Generated file
r/man/read_ipc_stream.Rd: Generated file
r/man/vctrs_extension_array.Rd: Generated file
r/man/write_dataset.Rd: Generated file
r/man/write_feather.Rd: Generated file
r/man/write_ipc_file.Rd: Generated file
r/man/write_ipc_stream.Rd: Generated file
r/man/write_to_raw.Rd: Generated file

Copilot

Pull request overview

Copilot reviewed 25 out of 39 changed files in this pull request and generated 2 comments.

Files not reviewed (14)

r/man/FileFormat.Rd: Generated file
r/man/RecordBatchReader.Rd: Generated file
r/man/RecordBatchWriter.Rd: Generated file
r/man/dataset_factory.Rd: Generated file
r/man/open_dataset.Rd: Generated file
r/man/read_feather.Rd: Generated file
r/man/read_ipc_file.Rd: Generated file
r/man/read_ipc_stream.Rd: Generated file
r/man/vctrs_extension_array.Rd: Generated file
r/man/write_dataset.Rd: Generated file
r/man/write_feather.Rd: Generated file
r/man/write_ipc_file.Rd: Generated file
r/man/write_ipc_stream.Rd: Generated file
r/man/write_to_raw.Rd: Generated file

Copilot

Pull request overview

Copilot reviewed 25 out of 39 changed files in this pull request and generated 1 comment.

Files not reviewed (14)

r/man/FileFormat.Rd: Generated file
r/man/RecordBatchReader.Rd: Generated file
r/man/RecordBatchWriter.Rd: Generated file
r/man/dataset_factory.Rd: Generated file
r/man/open_dataset.Rd: Generated file
r/man/read_feather.Rd: Generated file
r/man/read_ipc_file.Rd: Generated file
r/man/read_ipc_stream.Rd: Generated file
r/man/vctrs_extension_array.Rd: Generated file
r/man/write_dataset.Rd: Generated file
r/man/write_feather.Rd: Generated file
r/man/write_ipc_file.Rd: Generated file
r/man/write_ipc_stream.Rd: Generated file
r/man/write_to_raw.Rd: Generated file

  expect_snapshot(
-    write_dataset(df, dst_dir, format = "feather", nonsensical_arg = "blah-blah"),
+    write_dataset(df, dst_dir, format = "ipc", nonsensical_arg = "blah-blah"),
    error = TRUE
  )


Copilot

Pull request overview

Copilot reviewed 25 out of 39 changed files in this pull request and generated no new comments.

Files not reviewed (14)

r/man/FileFormat.Rd: Generated file
r/man/RecordBatchReader.Rd: Generated file
r/man/RecordBatchWriter.Rd: Generated file
r/man/dataset_factory.Rd: Generated file
r/man/open_dataset.Rd: Generated file
r/man/read_feather.Rd: Generated file
r/man/read_ipc_file.Rd: Generated file
r/man/read_ipc_stream.Rd: Generated file
r/man/vctrs_extension_array.Rd: Generated file
r/man/write_dataset.Rd: Generated file
r/man/write_feather.Rd: Generated file
r/man/write_ipc_file.Rd: Generated file
r/man/write_ipc_stream.Rd: Generated file
r/man/write_to_raw.Rd: Generated file

Comments suppressed due to low confidence (5)

r/R/ipc-stream.R:120

Same issue as write_ipc_stream(): calling .Deprecated() without an explicit old= will likely warn that read_ipc_stream() is deprecated, rather than warning about deprecated extra ... arguments.

  if (length(list(...)) > 0) {
    .Deprecated(
      msg = paste(
        "Extra arguments passed through `...` in `read_ipc_stream()`",
        "are deprecated and ignored.",
        "They will be removed in a future version."
      )
    )

r/R/feather.R:32

write_feather() still supports version = 1, but the inherited parameter docs for chunk_size, compression, and compression_level no longer mention the V1 restrictions enforced by check_feather_v1_options(). This makes the docs inconsistent with actual behavior for users still writing legacy V1 files.

#' @inheritParams write_ipc_file
#' @param version integer Feather file version, Version 1 or Version 2. Version 2 is the default.
#'

r/R/ipc-stream.R:47

.Deprecated() is called without specifying old=/new=, which means the warning will likely state that write_ipc_stream() itself is deprecated (the default old), even though only passing extra ... args is being deprecated. This is misleading for users and makes it harder to see what is actually deprecated.

This issue also appears on line 113 of the same file.

  if (length(list(...)) > 0) {
    .Deprecated(
      msg = paste(
        "Extra arguments passed through `...` in `write_ipc_stream()`",
        "are deprecated and ignored.",
        "They will be removed in a future version."
      )
    )

r/R/dataset-write.R:150

Using .Deprecated() here without old=/new= will likely emit a warning that write_dataset() is deprecated (because old defaults to the current call), even though only format = "feather" is deprecated. Consider specifying old/new so the warning points at the deprecated argument value instead of the function.

  if (format == "feather") {
    .Deprecated(
      msg = '`format = "feather"` is deprecated; use `format = "ipc"` instead.'
    )
  }

r/R/dataset-format.R:93

As written, .Deprecated() will likely report that FileFormat$create() is deprecated (default old), rather than warning specifically about the deprecated format = "feather" value. Set old=/new= so the warning is scoped to the argument value being deprecated.

    if (format == "feather") {
      .Deprecated(
        msg = '`format = "feather"` is deprecated; use `format = "ipc"` instead.'
      )
    }

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Copilot

Pull request overview

Copilot reviewed 30 out of 44 changed files in this pull request and generated no new comments.

Files not reviewed (14)

r/man/FileFormat.Rd: Generated file
r/man/RecordBatchReader.Rd: Generated file
r/man/RecordBatchWriter.Rd: Generated file
r/man/dataset_factory.Rd: Generated file
r/man/open_dataset.Rd: Generated file
r/man/read_feather.Rd: Generated file
r/man/read_ipc_file.Rd: Generated file
r/man/read_ipc_stream.Rd: Generated file
r/man/vctrs_extension_array.Rd: Generated file
r/man/write_dataset.Rd: Generated file
r/man/write_feather.Rd: Generated file
r/man/write_ipc_file.Rd: Generated file
r/man/write_ipc_stream.Rd: Generated file
r/man/write_to_raw.Rd: Generated file

Comments suppressed due to low confidence (3)

r/R/ipc-stream.R:39

length(list(...)) forces evaluation of the ... arguments. Since these are explicitly ignored, this changes behavior (and can introduce side effects / errors) for callers that pass expensive or erroring expressions. You can detect whether ... was supplied without evaluating it.

  if (length(list(...)) > 0) {

r/R/ipc-stream.R:113

Same issue as write_ipc_stream(): length(list(...)) evaluates ignored ... arguments. Use a non-evaluating check so callers passing extra args don't trigger side effects just from the deprecation warning.

  if (length(list(...)) > 0) {

r/R/feather.R:32

The docs now inherit chunk_size/compression/compression_level from write_ipc_file(), but write_feather(version = 1) still errors if these are set to non-default values. Adding a brief note to the version parameter docs would prevent confusion for users still writing Feather V1 during the deprecation period.

#' @inheritParams write_ipc_file
#' @param version integer Feather file version, Version 1 or Version 2. Version 2 is the default.
#'

conbench-apache-arrow · 2026-07-30T14:24:55Z

After merging your PR, Conbench analyzed the 4 benchmarking runs that have been run so far on merge-commit deed9c0.

There were no benchmark performance regressions. 🎉

The full Conbench report has more details. It also includes information about 111 possible false positives for unstable benchmarks that are known to sometimes produce them.

github-actions Bot added Component: R awaiting committer review Awaiting committer review labels Feb 13, 2026

thisisnic force-pushed the GH-49237_feather_deprecation branch from d3eca24 to d32a2e3 Compare February 16, 2026 10:32

piyushka-ally mentioned this pull request Apr 2, 2026

GH-49232: [Python] deprecate feather python #49590

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thisisnic force-pushed the GH-49237_feather_deprecation branch from d7c26bb to 71a2ff5 Compare April 6, 2026 07:28

github-actions Bot added Component: Parquet Component: Documentation labels Apr 6, 2026

thisisnic marked this pull request as ready for review May 28, 2026 09:54

thisisnic requested a review from jonkeane as a code owner May 28, 2026 09:54

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tadeja mentioned this pull request Jul 1, 2026

GH-49231: [C++] Deprecate Feather reader and writer #50321

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thisisnic force-pushed the GH-49237_feather_deprecation branch from 2a8bf3d to 62c0745 Compare July 13, 2026 19:34

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Comment thread r/tests/testthat/test-dataset-write.R Outdated

Comment on lines 602 to 605

expect_snapshot(

write_dataset(df, dst_dir, format = "feather", nonsensical_arg = "blah-blah"),

write_dataset(df, dst_dir, format = "ipc", nonsensical_arg = "blah-blah"),

error = TRUE

)

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thisisnic and others added 12 commits July 28, 2026 16:34

Update read/write feather

3627e7c

Swap out read/write Feather for IPC

cf707aa

Update tests, improve wording

53cf9de

Add deprecations to other areas we missed

28d7249

Update docs

81703c3

Remove unused ellipses

c00367e

deprecate ellipses

1653c25

Fix docs

64c1d74

Potential fix for pull request finding

8b70cd9

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delete duplictaed test

418d670

Delete duplicated test and update vignettes to remove refs to feather

d4088d2

Update snapshot

ee4b0c3

Copilot AI review requested due to automatic review settings July 28, 2026 20:38

thisisnic force-pushed the GH-49237_feather_deprecation branch from 82901e5 to ee4b0c3 Compare July 28, 2026 20:38

thisisnic merged commit deed9c0 into apache:main Jul 28, 2026
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thisisnic removed the awaiting change review Awaiting change review label Jul 28, 2026

thisisnic mentioned this pull request Jul 28, 2026

[R] Deprecate Feather reader and writer #49237

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thisisnic mentioned this pull request Jul 30, 2026

[R] Add read_ipc_file and write_ipc_file to _pkgdown.yml reference index #50744

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thisisnic commented Feb 13, 2026 •

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