Add opt-in ~/ asset-path expansion for Razor components (compiler) - #84796
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Add opt-in ~/ asset-path expansion for Razor components (compiler)#84796chsienki wants to merge 5 commits into
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Introduce the descriptor and property metadata the Razor compiler uses to recognize opt-in asset-path expansion, ahead of the discovery and lowering that consume them: - AssetPathMetadata carries a single (element, attribute) pair declared via [AcceptsAssetPath], surfaced as a tag-helper descriptor. - PropertyMetadata.AcceptsAssetPath marks a component parameter opted in via [AssetPath]. - New AssetPath / AcceptsAssetPath members on the TagHelperKind, MetadataKind, and TagHelperProducerKind enums, with the component-kind range extended to include the new tag-helper kind. - ComponentsApi gains the well-known metadata names for the [AssetPath] and [AcceptsAssetPath] attributes and the AssetPathAttributes convention type. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: ef56ab10-2d3d-4e55-a318-3d03bfbdd713
Read the runtime's asset-path opt-in metadata during tag-helper discovery: - AcceptsAssetPathTagHelperProducer finds the public AssetPathAttributes convention type and emits one carrier tag-helper descriptor per declared (element, attribute) pair, following the BindAttributes / EventHandlers model. The descriptors declare no tag-matching rules; they exist only to carry the allowlist to the lowering pass. - ComponentTagHelperProducer records [AssetPath] on a component parameter as PropertyMetadata.AcceptsAssetPath. - CompilerFeatures registers the new producer. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: ef56ab10-2d3d-4e55-a318-3d03bfbdd713
Rewrite literal ~/-prefixed attribute values into Assets["..."] expressions, but only where the target has opted in: - HTML element attributes whose (element, attribute) pair appears in the discovered [AcceptsAssetPath] allowlist. - Component parameters whose bound attribute has PropertyMetadata.AcceptsAssetPath. The pass reads the full discovered tag-helper set from ITagHelperFeature so the allowlist is compilation-global rather than scoped to the document's in-scope tag helpers. Mixed literal/expression content on an opted-in attribute is reported as RZ10025. Expansion is gated on Razor language version 11.0. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: ef56ab10-2d3d-4e55-a318-3d03bfbdd713
Cover opted-in expansion for HTML elements and component parameters, plus the backward-compatible cases where ~/ is left untouched: no [AssetPath], an attribute outside the allowlist, bare ~, explicit @() expressions, pre-11.0 language version, and mixed content (RZ10025). Baselines are generated with: dotnet test src/Razor/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/Microsoft.AspNetCore.Razor.Language.UnitTests.csproj /p:GenerateBaselines=true Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: ef56ab10-2d3d-4e55-a318-3d03bfbdd713
Add the feature design doc and record the discovery/allowlist pattern and the baseline-regeneration workflow in the agent knowledge base. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: ef56ab10-2d3d-4e55-a318-3d03bfbdd713
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What this does
Adds opt-in, compile-time expansion of literal
~/-prefixed attribute values in.razorfiles intoAssets["..."]expressions, so<img src="~/images/logo.png">becomes<img src="@Assets["images/logo.png"]">-- only where the target has explicitly opted in:(element, attribute)pair the runtime declares via[AcceptsAssetPath(elementName, attributeName)]on a publicAssetPathAttributesconvention type (built-in allowlist:img[src],link[href],script[src]).[AssetPath].When nothing is opted in,
~/is left untouched -- existing markup is unaffected (no ambient behavior, so no MSBuild opt-out is needed).Design
AcceptsAssetPathTagHelperProducerdiscovers theAssetPathAttributesconvention type during tag-helper discovery and emits carrierTagHelperDescriptors (AssetPathMetadata) with no tag-matching rules -- they exist purely to carry the allowlist to the lowering pass.[AssetPath]on a component parameter is recorded asPropertyMetadata.AcceptsAssetPath.ComponentTildePathPass(anIRazorOptimizationPass, Order 75) reads the full discovered tag-helper set viaITagHelperFeature(compilation-global, not scoped to the document's in-scope tag helpers), builds an element -> attributes allowlist once per engine, and rewrites only opted-in single-literal~/values. Mixed literal/expression content on an opted-in attribute is reported as RZ10025. Gated on Razor language version 11.0.Commits
AssetPathMetadata+PropertyMetadata.AcceptsAssetPath)[AssetPath]/[AcceptsAssetPath]declarations (producer + registration)~/literals viaComponentTildePathPass(+ RZ10025)docs/razor/tilde-path-expansion.md)Each commit builds and is test-green.
Testing
ComponentCodeGenerationTestBaseTildePath_*cases cover opted-in expansion (HTML + component params) and the backward-compatible non-expansion cases (not opted in, attribute outside the allowlist, bare~, explicit@(), pre-11.0, mixed content). 15/15 green.Related
~/asset paths in Razor components #84793Microsoft Reviewers: Open in CodeFlow