fix(linter/plugins): pass all args to CFG event handlers when 2 rules use same handler

[overlookmotel]

Fix #18555.

CFG event handlers receive multiple arguments (unlike standard AST node visit functions which only receive node). The code which merges multiple visitors into one was built on assumption that all visit functions take a single argument so merges 2 function like this:

fn merge(visit1, visit2) {
  return (node) => {
    visit1(node);
    visit2(node);
  };
}

This works well for AST node visit functions, but not for CFG event handlers - visit1 and visit2 only get called with the first argument, and the remaining arguments are lost.

Fix this by adding a 2nd function for merging CFG event handlers, which passes through all arguments:

fn mergeCfg(handle1, handle2) {
  return (...args) => {
    handle1(...args);
    handle2(...args);
  };
}

[overlookmotel]

• fix(linter/plugins): pass all args to CFG event handlers when 2 rules use same handler #18683 👈 (View in Graphite)
• main

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[Copilot]

Pull request overview

This pull request fixes a bug where Control Flow Graph (CFG) event handlers were not receiving all their arguments when multiple rules registered handlers for the same CFG event. The original merge logic assumed all visitor functions take a single argument (like AST node visitors), but CFG event handlers take multiple arguments (e.g., onCodePathSegmentLoop takes fromSegment, toSegment, and node).

Changes:

• Added a new mergeCfgVisitFns function that uses rest parameters (...args) to pass all arguments through to merged CFG event handlers
• Added test coverage by introducing a second rule that registers a CFG event handler, ensuring the merge logic is exercised
• Updated test fixtures to use the renamed plugin and enable both rules

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
apps/oxlint/src-js/plugins/visitor.ts	Adds CfgVisitFn type and mergeCfgVisitFns function to properly merge CFG event handlers with all arguments preserved
apps/oxlint/test/fixtures/cfg/plugin.ts	Adds a second rule with onCodePathSegmentLoop handler to test argument passing when handlers are merged
apps/oxlint/test/fixtures/cfg/.oxlintrc.json	Enables both rules to trigger handler merging; updates plugin name from "error-plugin" to "cfg-plugin"
apps/oxlint/test/fixtures/cfg/output.snap.md	Updates expected test output to reflect plugin rename and 2 rules being active
apps/oxlint/test/fixtures/cfg/options.json	Removes singleThread option (file deletion)

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[overlookmotel]

Merge activity

• Jan 29, 12:47 AM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Jan 29, 12:47 AM UTC: overlookmotel added this pull request to the Graphite merge queue.
• Jan 29, 12:53 AM UTC: Merged by the Graphite merge queue.