test(filesystem): expand remote emulator integration coverage

[hampsterx]

Summary

• Add xdist-safe, controller-managed S3, Azure, and GCS emulators with pinned images.
• Cover remote formats, compression, globs, failures, native destination writes, cross-provider round trips, and S3 incremental loading.
• Refresh S3 listings between repeated loads and support Azure destination connection strings.
• Avoid emulator startup for unrelated targeted tests while keeping the fast lane Docker-free.
• Document Azure connection-string authentication, credential exclusivity, and repeated S3 load behavior.

Scope

• Closes Filesystem: Integration tests for remote filesystems #247.
• Related to Filesystem: Migrate from HttpSource to fsspec.HTTPFileSystem #231, Filesystem: Migrate remote filesystem adapters from fsspec to pyarrow.fs (Azure Blob Storage, GCS, HDFS, S3) #233, and Filesystem: Clarify filesystem_incremental option ownership in fsspec sources #256.
• GCS destination writes remain out of scope because the destination has no emulator endpoint credential path.
• The filesystem constructor assertion is S3-only; the GCS and Azure filesystem_incremental behavior remains tracked by Filesystem: Clarify filesystem_incremental option ownership in fsspec sources #256.

Changes

• Share one controller-managed emulator container per backend across xdist workers.
• Add remote read, write, selection, failure, round-trip, and incremental integration coverage.
• Disable S3 listings caching so repeated incremental loads discover new objects.
• Add Azure destination connection-string support and reject mixed Azure credential modes.
• Document the new Azure authentication path and validation behavior.

Review

• Internal: one correctness fix and three consistency fixes applied.
• Claude: no defects; applied its api_version documentation and parsed pytest-target suggestions. Two scope/refactor suggestions were noted.
• Open-weights GLM: final focused review reported no significant findings. Its earlier agentic pass raised only low/informational notes.
• Codex: skipped because it is the same harness performing this workflow.

Test plan

• Serial integration: 20 passed in 3m 38s.
• Final default xdist run: 20 passed in 2m 22s, with one container per backend.
• Docker-disabled fast lane: 884 passed, 44 skipped.
• Isolated spreadsheet lane: 41 passed.
• Ruff formatting/lint, ty, and pyproject validation.
• Exact gitleaks CI container command, no leaks found.
• Sphinx warning-as-error build.
• Breaking the Azure destination credential path makes the write test fail, verified manually.
• Claude and GLM final-diff review.

[coderabbitai]

Important

Review skipped

Auto reviews are limited based on label configuration.

🏷️ Required labels (at least one) (1)

• coderabbit-review

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro Plus

Run ID: b03ad3f1-9e1b-4393-9eca-9503942bb4b8

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[read-the-docs-community]

Documentation build overview

📚 omniload | 🛠️ Build #33880179 | 📁 Comparing f7ac9d0 against latest (747b6aa)

  🔍 Preview build  

5 files changed · ± 5 modified

± Modified

• changelog.html
• supported-sources/azure-storage.html
• supported-sources/filesystem.html
• supported-sources/ods.html
• supported-sources/xlsx.html

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 59.52%. Comparing base (7e3d5f8) to head (f7ac9d0).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #273      +/-   ##
==========================================
+ Coverage   59.45%   59.52%   +0.07%     
==========================================
  Files         234      234              
  Lines       10977    10992      +15     
==========================================
+ Hits         6526     6543      +17     
+ Misses       4451     4449       -2     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[amotl]

Another wonderful cleanup & bundling patch from your pen, thank you!
Acknowledged modulo fixing CI.

[amotl]

Currently the branch seems to have conflicts, so the CI workflow didn't start at all after your recent adjustments.