fix: store section with scope reads

[DylanPiercey]

Description

Fixes a regression caused by #3021 which caused the compiler to error when attempting to write out the reads for some signals.

Also refactor and cleanup the signal construction and hasSideEffect logic a bit.

[changeset-bot]

🦋 Changeset detected

Latest commit: 7acdc2c

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@marko/runtime-tags	Patch

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[coderabbitai]

Walkthrough

The changes fix a bug in the Marko compiler where section information was not stored during scope reads. A new changeset documents the patch for @marko/runtime-tags. The fix modifies how references track section metadata by explicitly storing section information in the reference extra object. The createScopeReadExpression function signature is updated to default the section parameter to reference.section, and the Signal interface is refactored to use concrete boolean fields and union-undefined types with adjusted side-effect propagation logic. A new test fixture template is added.

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely summarizes the main change: storing section information with scope reads, which directly addresses the regression fix described in the PR.
Description check	✅ Passed	The description is directly related to the changeset, explaining the regression fix from PR #3021 and the signal construction refactoring that the changes implement.

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✨ Finishing touches

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Actionable comments posted: 0

🧹 Nitpick comments (1)

packages/runtime-tags/src/translator/util/signals.ts (1)

63-86: Excellent refactoring to explicit interface fields.

Converting Signal from a type to an interface and using concrete boolean fields (hasDynamicSubscribers, hasSideEffect) instead of optional fields improves type safety and code clarity. The explicit undefined unions for extraArgs, prependStatements, and buildAssignment make the API contract clearer.

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Reviewing files that changed from the base of the PR and between 59a90bf and 7acdc2c.

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• packages/runtime-tags/src/__tests__/fixtures/native-tag-ref-and-update/__snapshots__/.name-cache.json is excluded by !**/__snapshots__/** and included by **
• packages/runtime-tags/src/__tests__/fixtures/native-tag-ref-and-update/__snapshots__/csr-sanitized.expected.md is excluded by !**/__snapshots__/** and included by **
• packages/runtime-tags/src/__tests__/fixtures/native-tag-ref-and-update/__snapshots__/csr.expected.md is excluded by !**/__snapshots__/** and included by **
• packages/runtime-tags/src/__tests__/fixtures/native-tag-ref-and-update/__snapshots__/dom.expected/template.hydrate.js is excluded by !**/__snapshots__/** and included by **
• packages/runtime-tags/src/__tests__/fixtures/native-tag-ref-and-update/__snapshots__/dom.expected/template.js is excluded by !**/__snapshots__/** and included by **
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• packages/runtime-tags/src/__tests__/fixtures/native-tag-ref-and-update/__snapshots__/resume-sanitized.expected.md is excluded by !**/__snapshots__/** and included by **
• packages/runtime-tags/src/__tests__/fixtures/native-tag-ref-and-update/__snapshots__/resume.expected.md is excluded by !**/__snapshots__/** and included by **
• packages/runtime-tags/src/__tests__/fixtures/native-tag-ref-and-update/__snapshots__/ssr-sanitized.expected.md is excluded by !**/__snapshots__/** and included by **
• packages/runtime-tags/src/__tests__/fixtures/native-tag-ref-and-update/__snapshots__/ssr.expected.md is excluded by !**/__snapshots__/** and included by **

📒 Files selected for processing (5)

• .changeset/eager-rabbits-live.md
• packages/runtime-tags/src/__tests__/fixtures/native-tag-ref-and-update/template.marko
• packages/runtime-tags/src/translator/util/references.ts
• packages/runtime-tags/src/translator/util/scope-read.ts
• packages/runtime-tags/src/translator/util/signals.ts

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• GitHub Check: test: node@20

🔇 Additional comments (8)

.changeset/eager-rabbits-live.md (1)

1-5: LGTM!

The changeset properly documents the patch for @marko/runtime-tags and clearly describes the fix for storing section information during scope reads.

packages/runtime-tags/src/translator/util/references.ts (1)

263-265: LGTM! Core fix for the regression.

The introduction of the intermediate refExtra variable and explicit assignment of refExtra.section = refSection ensures that section information is properly stored during scope reads. This addresses the regression mentioned in the PR description where the compiler was erroring when attempting to write out reads for some signals.

The pattern of explicitly storing section metadata aligns with the related changes in scope-read.ts.

packages/runtime-tags/src/translator/util/scope-read.ts (3)

77-79: Good API improvement with default parameter.

The default parameter section = reference.section simplifies the calling convention and makes the typical case (where section matches reference.section) more explicit. This reduces the need for callers to pass undefined.

---

90-94: LGTM! Explicit section metadata attachment.

The conditional attachment of exprExtra.read and exprExtra.section ensures that section information is properly stored when the reference is in the same section and is not a DOM binding. This complements the fix in references.ts and ensures consistent section tracking across scope reads.

---

83-85: Clean scope selection logic.

The simplified ternary clearly distinguishes between local bindings (using scopeIdentifier) and non-local bindings (using getScopeExpression), improving code readability.

packages/runtime-tags/src/translator/util/signals.ts (2)

228-241: Clear and comprehensive signal initialization.

The explicit initialization of all Signal fields, particularly the inline computation of hasSideEffect based on binding characteristics, makes the behavior deterministic and easier to understand. The logic properly covers arrays, DOM bindings, let bindings, cross-section references, closures, and hoists.

---

604-622: Good centralization of side effect propagation.

Explicitly setting providerSignal.hasSideEffect = true when establishing subscriptions centralizes the side-effect determination logic. This is clearer than the previous approach where side effects were inferred across multiple code paths.

packages/runtime-tags/src/__tests__/fixtures/native-tag-ref-and-update/template.marko (1)

1-5: Appropriate test fixture for the regression fix.

This test fixture properly exercises the scenario where the compiler was failing to store section information during scope reads. It combines:

• A let binding (count)
• A native tag reference (/btn)
• Data attribute binding (data-count=count)
• A script that updates the DOM (btn.textContent = "after")

This effectively validates that the fix correctly handles section information for native tag references and subsequent updates.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.13%. Comparing base (59a90bf) to head (7acdc2c).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3032      +/-   ##
==========================================
- Coverage   89.13%   89.13%   -0.01%     
==========================================
  Files         375      375              
  Lines       47020    47018       -2     
  Branches     4023     4019       -4     
==========================================
- Hits        41912    41910       -2     
  Misses       5059     5059              
  Partials       49       49              

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