Oxc Walker Skilld

oxc-project/oxc-walker oxc-walker

Version: 0.7.0 (Jan 2026) Deps: magic-regexp@^0.10.0 Tags: latest: 0.7.0 (Jan 2026)

References: package.json — exports, entry points • README — setup, basic usage • GitHub Issues — bugs, workarounds, edge cases • Releases — changelog, breaking changes, new APIs

Search

Use skilld search instead of grepping .skilld/ directories — hybrid semantic + keyword search across all indexed docs, issues, and releases. If skilld is unavailable, use npx -y skilld search.

skilld search "query" -p oxc-walker
skilld search "issues:error handling" -p oxc-walker
skilld search "releases:deprecated" -p oxc-walker

Filters: docs:, issues:, releases: prefix narrows by source type.

API Changes

This section documents version-specific API changes -- prioritize recent major/minor releases.

• NEW: ScopeTrackerVariable -- exported class in v0.7.0, enables instanceof checks on results from scopeTracker.getDeclaration(). Previously internal-only; LLMs will not know these classes are importable source

• NEW: ScopeTrackerFunction -- exported class in v0.7.0, represents function declarations tracked by ScopeTracker. Import directly from oxc-walker for type narrowing source

• NEW: ScopeTrackerImport -- exported class in v0.7.0, represents import declarations tracked by ScopeTracker. Has .importNode property for accessing the full ImportDeclaration source

• NEW: ScopeTrackerFunctionParam -- exported class in v0.7.0, represents function parameters tracked by ScopeTracker. Has .fnNode for accessing the parent function node source

• NEW: ScopeTrackerIdentifier -- exported class in v0.7.0, represents plain identifiers (e.g. class/enum names) tracked by ScopeTracker source

• NEW: ScopeTrackerCatchParam -- exported class in v0.7.0, represents catch clause parameters tracked by ScopeTracker. Has .catchNode for the parent CatchClause source

• NEW: getUndeclaredIdentifiersInFunction(node) -- exported in v0.7.0, returns string[] of identifier names referenced but not declared within a Function or ArrowFunctionExpression node source

• NEW: isBindingIdentifier(node, parent) -- exported in v0.7.0, returns boolean indicating whether a node is a binding identifier given its parent context source

• DEPRECATED: ScopeTrackerFunctionParam.start -- use .fnNode.start instead. The representation of this position may change in future versions source

• DEPRECATED: ScopeTrackerFunctionParam.end -- use .fnNode.end instead. The representation of this position may change in future versions source

• NEW: ScopeTrackerNode type -- union type exported in v0.7.0: ScopeTrackerFunctionParam | ScopeTrackerFunction | ScopeTrackerVariable | ScopeTrackerIdentifier | ScopeTrackerImport | ScopeTrackerCatchParam. Use for typing getDeclaration() results source

• BREAKING: oxc-parser peer dependency -- v0.6.0 requires oxc-parser v0.98.0+. Older oxc-parser versions are no longer compatible source

Also changed: WalkOptions type exported v0.7.0 · WalkerEnter type exported v0.7.0 · WalkerLeave type exported v0.7.0 · WalkerCallbackContext type exported v0.7.0 · WalkerThisContextEnter type exported v0.7.0 · WalkerThisContextLeave type exported v0.7.0 · Identifier type exported v0.7.0 · ScopeTrackerOptions type exported v0.7.0

Best Practices

• Use regular function expressions (not arrow functions) for enter/leave callbacks -- this.skip(), this.replace(), and this.remove() are bound via this context and won't work with arrow functions source

// correct
walk(ast, { enter(node) { this.skip() } })
// broken -- this.skip is undefined
walk(ast, { enter: (node) => { this.skip() } })

• Use parseAndWalk over separate parseSync + walk when you only need a single pass -- it returns ParseResult (including program) so you can still re-walk the AST if needed later source

• For hoisted declaration resolution, use the two-pass pattern: create ScopeTracker({ preserveExitedScopes: true }), run parseAndWalk as a pre-pass to collect all declarations, call scopeTracker.freeze(), then walk(program, { scopeTracker }) for analysis -- without this, getDeclaration() returns null for identifiers declared after their usage in source order source

• Do not use this.replace() or this.remove() when a ScopeTracker is attached -- the scope tracker will not update its internal declarations, leaving stale scope data source

• this.remove() takes precedence over this.replace() -- if both are called in the same callback, the node is removed regardless of replacement source

• this.skip() is only available in enter, not leave, and skipping a node also prevents its leave() callback from firing -- this means ScopeTracker state can become inconsistent if you skip nodes that create scopes source

• Type-narrow ScopeTrackerNode using the .type discriminant or instanceof (v0.7.0+) to access parent declaration nodes -- ScopeTrackerVariable exposes .variableNode, ScopeTrackerImport exposes .importNode, ScopeTrackerCatchParam exposes .catchNode, ScopeTrackerFunctionParam exposes .fnNode source

• isCurrentScopeUnder(scope) uses strict child checking -- it returns false when the current scope equals the given scope, only true for descendants source

• Use getUndeclaredIdentifiersInFunction(node) to find free variables (closures) in a function or arrow function expression -- useful for tree-shaking analysis and determining if a function can be safely hoisted or moved source

• ScopeTrackerFunctionParam.start and .end are deprecated -- access the function's position via .fnNode.start and .fnNode.end instead source