Formatter: Extract Text Flow Engine

[marcoroth]

This pull request extracts the text flow formatting system from FormatPrinter into a dedicated TextFlowEngine class and pure helper functions. The text flow system handles formatting of mixed text + inline elements + ERB content with intelligent word wrapping and punctuation handling.

This is mostly motived be the number of bugs we have seen around inline text formatting and punctuation. Related issues:

• Formatter: breaks rendering for inline tags by adding spacing around/inside #251
• Formatter: ERB/HTML formatting corrupted when line contains em dash (—) and curly apostrophe (’) #360
• Formatter: inserts whitespace around interpolations and elements #469
• Formatter: Adds whitespace in cases where there was not whitespace #478
• Formatter keeps adding new text and <br> tag recursively #588
• Formatter: Whitespace inserted and removed in various situations #609
• Formatter: Removes whitespace in text content #727
• Formatter: herb-format breaks HTML having <span> and if-else block #789
• Formatter: Adding whitespace before ' that follows Ruby tag #855
• Formatter: tags under div > span are combined into a single line #882
• Formatter: Newline added before . that follows ERB tag plus other issues, perhaps related to <br> tag #903
• Formatter: Formatting adds whitespace that is unwanted inside block content #904
• Formatter: Full-width space (U+3000) is converted to half-width space in HTML/ERB formatting #930
• Formatter: Punctuation after ERB #931
• Formatter: Inlines HTML tags when within max line length #1017
• Formatter: Shouldn't inline multiple ruby tags #1024
• Formatter: Spans are corrected to multiline #1095

The hope is that, extracting the text flow engine, makes the formatter easier to test and reason about.

[pkg-pr-new]

npx https://pkg.pr.new/@herb-tools/formatter@1267

npx https://pkg.pr.new/@herb-tools/language-server@1267

npx https://pkg.pr.new/@herb-tools/linter@1267

commit: 65d848e

[github-actions]

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_{🌱 Grown from commit 65d848e}

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✅ Preview deployment has been cleaned up.