fix(linter): explicit-length-check inside ternary (#2165)

crates/oxc_linter/src/rules/unicorn/explicit_length_check.rs

@@ -348,6 +348,8 @@ fn test() {
         // need getStaticValue
         // ("const A_NUMBER = 2; const x = foo.length || A_NUMBER", None),
         ("class A { a(){ if(this.length); while(!this.size || foo);}}", None),
+        // Use of .size but not in conditional "test" position
+        ("const totalCount = tests.reduce((count, test) => count + (test.enabled ? test.maxSize : test.size), 0)", None),
     ];
 
     let fail = vec![
@@ -361,7 +363,10 @@ fn test() {
         ("const x = foo.length || bar()", None),
         ("() => foo.length && bar()", None),
         ("alert(foo.length && bar())", None),
+        // Use of .size in conditional "test" position
+        ("let foo = arr.length ? 'non-empty' : 'empty'", None),
     ];
+
     let fixes = vec![
         (
             r"if ( !!!( !foo.length && foo.length == 0 && foo.length < 1 && 0 === foo.length && 0 == foo.length && 1 > foo.length ) ||

crates/oxc_linter/src/snapshots/explicit_length_check.snap

@@ -64,4 +64,10 @@ expression: explicit_length_check
    ╰────
   help: Replace `.length` with `.length > 0`.
 
+  ⚠ eslint-plugin-unicorn(explicit-length-check): Use `.length > 0` when checking length is not zero.
+   ╭─[explicit_length_check.tsx:1:1]
+ 1 │ let foo = arr.length ? 'non-empty' : 'empty'
+   ·           ──────────
+   ╰────
+
 

crates/oxc_linter/src/utils/unicorn/boolean.rs

@@ -1,8 +1,9 @@
 use oxc_ast::{
-    ast::{CallExpression, Expression},
+    ast::{CallExpression, ConditionalExpression, Expression},
     AstKind,
 };
 use oxc_semantic::AstNode;
+use oxc_span::GetSpan;
 use oxc_syntax::operator::UnaryOperator;
 
 use crate::{ast_util::outermost_paren_parent, LintContext};
@@ -48,7 +49,6 @@ pub fn is_boolean_node<'a, 'b>(node: &'b AstNode<'a>, ctx: &'b LintContext<'a>)
     if matches!(
         parent.kind(),
         AstKind::IfStatement(_)
-            | AstKind::ConditionalExpression(_)
             | AstKind::WhileStatement(_)
             | AstKind::DoWhileStatement(_)
             | AstKind::ForStatement(_)
@@ -56,6 +56,14 @@ pub fn is_boolean_node<'a, 'b>(node: &'b AstNode<'a>, ctx: &'b LintContext<'a>)
         return true;
     }
 
+    if let AstKind::ConditionalExpression(ConditionalExpression {
+        test: conditional_test, ..
+    }) = parent.kind()
+    {
+        let expr_span = conditional_test.get_inner_expression().without_parenthesized().span();
+        return expr_span == node.kind().span();
+    }
+
     if is_logical_expression(parent) {
         return is_boolean_node(parent, ctx);
     }