From 123a93abdaf5d56f844f1967c55c4b994533cdf2 Mon Sep 17 00:00:00 2001
From: Matthieu Gomez <gomez.matthieu@gmail.com>
Date: Mon, 2 Feb 2026 11:48:41 -0500
Subject: [PATCH] Add Metal test with few fixed effects

Added a test case for regression with period fixed effects.
---
 test/fit.jl | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/test/fit.jl b/test/fit.jl
index 7612f52..966550c 100644
--- a/test/fit.jl
+++ b/test/fit.jl
@@ -721,6 +721,11 @@ end
 		local m = @formula Wage ~ Emp + fe(Firm) + fe(Year)
 		local x = reg(df, m, weights = :Output, method = method, double_precision = false)
 		@test coef(x) ≈  [- 0.043475472188120416] atol = 1e-3
+		# check Metal with very few fixed effects
+		df.period = df.Year .>= 1980
+		local m = @formula Wage ~ Emp + fe(Firm) + fe(period)
+		local x = reg(df, m, method = method, double_precision = false)
+		@test coef(x) ≈  [-0.0879211] atol = 1e-3
 	end
 end