Support checking for UndefVarError variable name in at-test_throws

stdlib/Test/src/Test.jl

@@ -812,7 +812,11 @@ function do_test_throws(result::ExecutionResult, orig_expr, extype)
             if extype isa LoadError && !(exc isa LoadError) && typeof(extype.error) == typeof(exc)
                 extype = extype.error # deprecated
             end
-            if isa(exc, typeof(extype))
+            # Support `UndefVarError(:x)` meaning `UndefVarError(:x, scope)` for any `scope`.
+            # Retains the behaviour from pre-v1.11 when `UndefVarError` didn't have `scope`.
+            if isa(extype, UndefVarError) && !isdefined(extype, :scope)
+                success = exc isa UndefVarError && exc.var == extype.var
+            else isa(exc, typeof(extype))
                 success = true
                 for fld in 1:nfields(extype)
                     if !isequal(getfield(extype, fld), getfield(exc, fld))

stdlib/Test/test/runtests.jl

@@ -1736,3 +1736,20 @@ end
         This is deprecated and may error in the future."""
     @test_deprecated msg2 @macroexpand @testset DefaultTestSet DefaultTestSet begin end
 end
+
+# Issue #54082
+module M54082 end
+@testset "@test_throws UndefVarError(:var)" begin
+    # Single-arg `UndefVarError` should match all `UndefVarError` for the
+    # same variable name, regardless of scope, to keep pre-v1.11 behaviour.
+    f54082() = var
+    @test_throws UndefVarError(:var) f54082()
+    # But if scope is set, then it has to match.
+    @test_throws UndefVarError(:var, M54082) M54082.var
+    let result = @testset NoThrowTestSet begin
+            # Wrong module scope
+            @test_throws UndefVarError(:var, Main) M54082.var
+        end
+        @test only(result) isa Test.Fail
+    end
+end