Engine: Compile-time optimizations for Action View tag helpers#1613
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Engine: Compile-time optimizations for Action View tag helpers#1613
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This pull request adds `framework` and `template_engine` configuration options to the `.herb.yml`. These top-level settings tell Herb what environment it's running in and what template engine is being used for compilation. This enables context-aware behavior across the toolchain. Configuration in `.herb.yml`: ```yml framework: actionview # ruby | actionview | hanami | sinatra (default: ruby) template_engine: herb # erubi | erb | herb (default: erubi) ``` Valid values are defined once in `config/options.yml` and code-generated into the relevant configuration files in all bindings. This allows us in the future to have more specific features tailored for each target framework and engine. This pull request is meant to lay the groundwork for: - Framework-aware linter rules, so that we can automatically enable/disable rules based on the framework (see #480) - Framework-aware compile-time optimizations. Knowing the framework context determines which helpers are available for optimization (like #1613) - Template engine compatibility, surfacing invalid syntax or other target engine's conventions across the toolchain (for example no ERB block support)
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This pull request adds compile-time optimization support for Action View tag helpers to
Herb::Engine.When
optimize: trueis passed toHerb::Engine, the parser transforms Action View helper calls (tag.*,content_tag,link_to,image_tag,javascript_tag,javascript_include_tag,turbo_frame_tag) into their HTML equivalents at compile time, producing optimized Ruby output that avoids runtime helper dispatch.When compile-time optimizations are enabled, the engine checks whether the template contains supported Action View helpers via the
Herb::ActionView::HelperRegistry.supportedmethod. If helpers are detected, the parser is invoked withaction_view_helpers: trueandtransform_conditionals: true, which also handles postfix if/unless and ternary conditionals containing helper calls.The pull request also includes comprehensive snapshot-based tests for all supported helpers, an
assert_optimized_output_matchhelper that validates optimized output against both standard Herb and ActionView+Erubi to ensure the rendered output matches.Additionally, we added a YAML-driven benchmark framework in
bench/action_view/with abin/benchCLI for compile-time and render-time comparisons. Early benchmarks show render-time improvements of 3-22x depending on the template, with a realistic 192-line page layout rendering 22x faster, and a helper-heavy template with all static values reaching up to 150x faster.The trade-off is compile time: Herb's parser is currently 10-90x slower than Erubi at compile time, so optimization adds overhead that needs to be amortized over multiple renders. But this is typically won back with 15-100 renders depending on template complexity and could also be done ahead of time, instead of the current on-the-fly approach used in Action View today.
Warning
Compile-time optimizations are experimental. Output may differ from standard ActionView rendering.
Resolves #653
Enables #1111