fix: pr-bug-scan validated finding from #2437 (#2445)

* fix: address pr-bug-scan validated finding from #2437

Fixed jsxElementReports: spread className now overrides earlier explicit className (later wins); expressionHasStyledScrollbarLiteral skips conditional/short-circuit branches so a conditional scrollbar

* test: cover styled scrollbar checker regressions

---------

Co-authored-by: orca-bug-scan-bot <orca-bug-scan-bot@stably.ai>
Co-authored-by: Neil <4138956+nwparker@users.noreply.github.com>

config/scripts/check-styled-scrollbars.test.mjs

@@ -129,6 +129,22 @@ describe('check-styled-scrollbars', () => {
     expect(reports).toHaveLength(0)
   })
 
+  it('reports inline vertical overflow when the scrollbar class is conditional or short-circuited', () => {
+    for (const classNameExpression of [
+      "enabled && 'scrollbar-sleek'",
+      "enabled ? 'scrollbar-sleek' : undefined",
+      "enabled || 'scrollbar-sleek'",
+      "enabled ?? 'scrollbar-sleek'"
+    ]) {
+      const reports = reportUnstyledScrollbars(
+        'Example.tsx',
+        `export function Example({ enabled }) { return <div className={${classNameExpression}} style={{ overflowY: 'auto' }} /> }`
+      )
+
+      expect(reports, classNameExpression).toHaveLength(1)
+    }
+  })
+
   it('reports logical inline style spreads without an Orca scrollbar class', () => {
     const reports = reportUnstyledScrollbars(
       'Example.tsx',
@@ -156,6 +172,15 @@ describe('check-styled-scrollbars', () => {
     expect(reports).toHaveLength(0)
   })
 
+  it('uses later spread className props over earlier explicit className props', () => {
+    const reports = reportUnstyledScrollbars(
+      'Example.tsx',
+      "export function Example() { return <div className=\"scrollbar-sleek\" {...{ className: 'overflow-y-auto' }} /> }"
+    )
+
+    expect(reports).toHaveLength(1)
+  })
+
   it('supports variant helper className config', () => {
     const reports = reportUnstyledScrollbars(
       'Example.tsx',

config/scripts/styled-scrollbars/styled-scrollbar-jsx-check.mjs

@@ -138,6 +138,20 @@ function expressionHasStyledScrollbarLiteral(node) {
       hasStyledScrollbar = true
       return
     }
+    // Why: a scrollbar literal that only renders on some branches must not be
+    // treated as covering an unconditional inline overflow. Skip conditional
+    // and short-circuit expressions when proving unconditional coverage.
+    if (ts.isConditionalExpression(current)) {
+      return
+    }
+    if (
+      ts.isBinaryExpression(current) &&
+      (current.operatorToken.kind === ts.SyntaxKind.AmpersandAmpersandToken ||
+        current.operatorToken.kind === ts.SyntaxKind.BarBarToken ||
+        current.operatorToken.kind === ts.SyntaxKind.QuestionQuestionToken)
+    ) {
+      return
+    }
     ts.forEachChild(current, visit)
   }
 
@@ -246,7 +260,12 @@ function jsxElementReports(node, filePath, sourceFile) {
 
   for (const attribute of node.attributes.properties) {
     if (ts.isJsxSpreadAttribute(attribute)) {
-      classExpression ??= spreadPropExpressions(attribute.expression, 'className').at(-1)
+      // Why: at runtime React applies attributes in source order, so a later
+      // spread that supplies className overrides an earlier explicit className.
+      const spreadClassExpression = spreadPropExpressions(attribute.expression, 'className').at(-1)
+      if (spreadClassExpression) {
+        classExpression = spreadClassExpression
+      }
       styleExpressions.push(...spreadPropExpressions(attribute.expression, 'style'))
     } else if (jsxAttributeName(attribute) === 'className') {
       classExpression = jsxAttributeExpression(attribute)