fix(rename): read and write source files as UTF-8 by anxkhn · Pull Request #6761 · reflex-dev/reflex

anxkhn · 2026-07-14T07:50:03Z

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Type of change

Bug fix (non-breaking change which fixes an issue)

What and why

reflex rename <new_name> walks the user's app and rewrites imports and the app
name in every .py and .md file. The read/modify/write in
rename_imports_and_app_name (reflex/utils/rename.py) used
Path.read_text() and Path.write_text() with no encoding= argument, so both
default to the platform's locale encoding. On a Western Windows locale that is
cp1252, not UTF-8.

The consequences on non-UTF-8 locales:

Silent corruption (Western Windows, cp1252): a UTF-8-authored file that
contains non-ASCII bytes (curly quotes in docstrings, accented identifiers or
string literals, emoji) is decoded as cp1252, rewritten, and written back as
cp1252, mangling the user's own source.
Hard failure (CJK codepages): read_text() raises UnicodeDecodeError,
aborting the rename partway through the tree and leaving some files already
rewritten and others not, i.e. an inconsistent app.

On a POSIX UTF-8 locale it round-trips, so this is effectively Windows-specific.

The fix passes encoding="utf-8" on both calls. This mirrors the repo's own
reflex/utils/path_ops.py find_replace, which already reads and writes the same
read/replace/write pattern with encoding="utf-8"; rename.py was the outlier.

Changes

reflex/utils/rename.py: add encoding="utf-8" to the read_text() and
write_text() calls in rename_imports_and_app_name (+2 / -2).
tests/units/test_prerequisites.py: add regression test
test_rename_imports_and_app_name_preserves_utf8, colocated with the existing
rename tests. It simulates a cp1252 default (monkeypatching Path.read_text /
write_text so a missing encoding falls back to cp1252, while an explicit
encoding= still passes through), writes a UTF-8 file with realistic non-ASCII
content, runs the rename, and asserts the bytes are preserved exactly and the
rename still happened. The test fails before the fix (UnicodeDecodeError) and
passes after.
news/<pr>.bugfix.md: towncrier changelog fragment.

Changes To Core Features:

Have you added an explanation of what your changes do and why you'd like us to include them? (above)
Have you written new tests for your core changes, as applicable?
Have you successfully ran tests with your changes locally?

Locally (all green):

uv run pytest tests/units/test_prerequisites.py -k rename -> 6 passed
uv run pytest tests/units/test_prerequisites.py tests/units/utils -> 677 passed, 4 skipped
uv run ruff check . (changed files) -> All checks passed
uv run ruff format --check . (changed files) -> already formatted
uv run pyright reflex/utils/rename.py tests/units/test_prerequisites.py -> 0 errors
uv run towncrier check --compare-with origin/main -> fragment found

greptile-apps · 2026-07-14T07:53:19Z

Greptile Summary

This PR makes reflex rename preserve source-file encodings across platforms. The main changes are:

Detect Python source encodings with tokenize.detect_encoding.
Read and write each Python file with its detected encoding.
Use UTF-8 explicitly for supported non-Python text files.
Add byte-level tests for UTF-8 and cp1252 source files.
Add a bug-fix changelog entry.

Confidence Score: 5/5

This looks safe to merge.

The declared-encoding failure is addressed with Python's standard source-encoding detection.
Reads and writes now use the same detected encoding.
Tests cover both UTF-8 files on non-UTF-8 locales and cp1252 encoding declarations.
No blocking issues were found in the updated code.

Important Files Changed

Filename	Overview
reflex/utils/rename.py	Detects declared Python source encodings and reuses them for reading and writing during rename.
tests/units/test_prerequisites.py	Adds byte-level tests for UTF-8 under a cp1252 locale and Python source declared as cp1252.
news/6714.bugfix.md	Documents the cross-platform source-encoding fix.

_{Reviews (4): Last reviewed commit: "test(rename): handle platform newlines" | Re-trigger Greptile}

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codspeed-hq · 2026-07-15T21:44:44Z

Merging this PR will not alter performance

✅ 26 untouched benchmarks
⏩ 8 skipped benchmarks¹

_{Comparing anxkhn:patch-13 (4f7d658) with main (1358e00)}

8 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

reflex rename reads every .py/.md file in the user's app with Path.read_text() and writes it back with Path.write_text(), neither of which passed encoding=. Both default to the platform locale encoding, which on Western Windows is cp1252 rather than UTF-8. UTF-8-authored source containing non-ASCII bytes (curly quotes, emoji, accented identifiers or docstrings) is therefore silently corrupted on a Western Windows locale, or aborts the rename partway with UnicodeDecodeError on a CJK codepage, leaving the tree in an inconsistent state. Pass encoding="utf-8" on both calls, matching path_ops.find_replace which already does this. Signed-off-by: Anas Khan <83116240+anxkhn@users.noreply.github.com>

Signed-off-by: Anas Khan <83116240+anxkhn@users.noreply.github.com>

anxkhn · 2026-07-27T18:36:54Z

fixed the windows ci failures in 4f7d658. the encoding assertions remain byte-exact while accounting for the platform newline emitted by the existing text-write behavior. focused tests, ruff, and pyright pass locally. @reflex-dev please take another look when ci completes.

anxkhn requested a review from a team as a code owner July 14, 2026 07:50

greptile-apps Bot reviewed Jul 14, 2026

View reviewed changes

Comment thread reflex/utils/rename.py Outdated

chatgpt-codex-connector Bot reviewed Jul 14, 2026

View reviewed changes

Comment thread reflex/utils/rename.py Outdated

Alek99 closed this Jul 15, 2026

Alek99 reopened this Jul 15, 2026

anxkhn force-pushed the patch-13 branch from 657b04c to df47168 Compare July 27, 2026 14:39

anxkhn added 3 commits July 28, 2026 00:04

fix(rename): preserve declared source encodings

8861983

Signed-off-by: Anas Khan <83116240+anxkhn@users.noreply.github.com>

test(rename): handle platform newlines

4f7d658

Signed-off-by: Anas Khan <83116240+anxkhn@users.noreply.github.com>

anxkhn force-pushed the patch-13 branch from df47168 to 4f7d658 Compare July 27, 2026 18:36

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fix(rename): read and write source files as UTF-8 - #6761

fix(rename): read and write source files as UTF-8#6761
anxkhn wants to merge 3 commits into
reflex-dev:mainfrom
anxkhn:patch-13

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anxkhn commented Jul 14, 2026

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Confidence Score: 5/5

Important Files Changed

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Merging this PR will not alter performance

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anxkhn commented Jul 27, 2026

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