Add PreviewMode option to formatter

[MichaReiser]

Summary

This PR adds the --preview and --no-preview options to the format command (hidden) and passes it through to the formatte.

Test Plan

I added the dbg(f.options().preview()) statement in FormatNodeRule::fmt and verified that the option gets correctly passed to the formatter.

[MichaReiser]

Current dependencies on/for this PR:

• main
  • PR Split implicit concatenated strings before binary expressions #7145
    • PR Formatter: Implicit concatenation in compare expressions #7193
      • PR Add FString support to binary like formatting #7215
        • PR Add PreviewMode option to formatter #7217 👈
          • PR Extract string part and normalized string #7219
            • PR Introduce StringContinuation data structure #7242
              • PR POC of Black's string preview style formatting #7567

This comment was auto-generated by Graphite.

[codspeed-hq]

CodSpeed Performance Report

Merging #7217 will degrade performances by 2.54%

_{Comparing add-preview-flag-to-formatter (65c5853) with main (41f0aad)}

Summary

❌ 1 regressions
✅ 24 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	add-preview-flag-to-formatter	Change
❌	linter/all-rules[numpy/ctypeslib.py]	32.6 ms	33.5 ms	-2.54%

[github-actions]

PR Check Results

Ecosystem

✅ ecosystem check detected no changes.

[konstin]

Is preview mode a global only flag or can it also be hierarchical?

[MichaReiser]

Is preview mode a global only flag or can it also be hierarchical?

I would expect it to be hierarchical the same way as any other configuration option.

CC: @zanieb

[konstin]

forgot to approve

[charliermarsh]

IMO it should match the behavior of other settings (and I assume it will by default based on the implementation): hierarchical, but providing it on the command-line overrides it for all files.

[MichaReiser]

Merge Activity

• Sep 8, 5:50 AM: Graphite rebased this pull request as part of a merge.
• Sep 8, 6:04 AM: @MichaReiser merged this pull request with Graphite.