Consistently error on full circle of circular import aliases #1904
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
ahejlsberg
requested review from
andrewbranch,
Copilot and
jakebailey
and removed request for
Copilot
|
Can some of these be unskipped, then? |
There was a problem hiding this comment.
Pull Request Overview
This PR ensures circular import alias errors are reported consistently on every node participating in the cycle, independent of checker partitioning.
- Introduces alias-target cycle detection via the type resolution stack (new TypeSystemPropertyNameAliasTarget) and removes the prior resolvingSymbol sentinel approach.
- Updates baselines to include additional circular alias diagnostics for all nodes in each cycle and removes skipped error baseline entries.
- Removes the InternalSymbolNameResolving constant and associated field from Checker.
Reviewed Changes
Copilot reviewed 15 out of 15 changed files in this pull request and generated 1 comment.
Show a summary per file
| File | Description |
|---|---|
| internal/checker/checker.go | Reworks alias resolution logic to use type resolution tracking for circular detection and adds AliasTarget property handling. |
| internal/ast/symbol.go | Removes obsolete InternalSymbolNameResolving constant tied to old sentinel mechanism. |
| internal/testrunner/compiler_runner.go | Drops prior skip entries now that circular alias errors are consistently reported. |
| testdata/baselines/reference/submodule/conformance/circular1.errors.txt.diff | Baseline diff reflecting additional circular alias error reported (grammar issue introduced). |
| testdata/baselines/reference/submodule/conformance/circular1.errors.txt | Updated baseline showing new error; contains a singular/plural grammar issue. |
| testdata/baselines/reference/submodule/conformance/circular3.errors*.txt* | Baselines updated to show full set of circular alias errors across both files. |
| testdata/baselines/reference/submodule/compiler/exportAsNamespaceConflict.errors*.txt* | Baselines updated to add circular alias diagnostic on export assignment. |
| testdata/baselines/reference/submodule/compiler/declarationEmitUnknownImport.errors*.txt* | Baselines updated to include circular alias diagnostics at import and export points. |
| testdata/baselines/reference/submodule/compiler/declarationEmitUnknownImport2.errors*.txt* | Baselines updated with additional circular alias diagnostics for malformed import/export. |
| testdata/baselines/reference/submodule/compiler/circularModuleImports.errors*.txt* | Baselines updated to report circular alias errors for both aliases in module scope. |
Yes, all but two of them! |
andrewbranch
approved these changes
Oct 20, 2025
jakebailey
approved these changes
Oct 20, 2025
| func (c *Checker) tryResolveAlias(symbol *ast.Symbol) *ast.Symbol { | ||
| links := c.aliasSymbolLinks.Get(symbol) | ||
| if links.aliasTarget != c.resolvingSymbol { | ||
| if links.aliasTarget != nil || c.findResolutionCycleStartIndex(symbol, TypeSystemPropertyNameAliasTarget) < 0 { |
There was a problem hiding this comment.
Hopefully this extra find isn't too expensive, given how often we resolve aliases.
There was a problem hiding this comment.
tryResolveAlias is only called when generating spelling correction suggestions, so not an issue at all. And anyway, every call to pushTypeResolution has a call to that find method with no issues.
github-merge-queue
bot
removed this pull request from the merge queue due to no response for status checks
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
With this PR we consistently error on all nodes in the full circle of circular import alias declarations. This in particular means that our error reporting is unaffected by the number of checkers used to check a program.
Fixes #1851.