From 6da25579aa7008ef7e3c002b556e7a2dbbbe3f8e Mon Sep 17 00:00:00 2001
From: Jishnu Bhattacharya <jishnub.github@gmail.com>
Date: Wed, 13 Sep 2023 16:47:59 +0400
Subject: [PATCH] Throw DomainError for out-of-domain evaluation (#538)

---
 src/polynomials/chebyshev.jl | 3 ++-
 test/ChebyshevT.jl           | 2 ++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/polynomials/chebyshev.jl b/src/polynomials/chebyshev.jl
index 1d43a2f5..2b42e4b7 100644
--- a/src/polynomials/chebyshev.jl
+++ b/src/polynomials/chebyshev.jl
@@ -135,7 +135,8 @@ julia> c.(-1:0.5:1)
 ```
 """
 function evalpoly(x::S, ch::ChebyshevT) where {S}
-    x ∉ domain(ch) && throw(ArgumentError("$x outside of domain"))
+    d = domain(ch)
+    x ∉ d && throw(DomainError(x, "evaluation point must lie in $d"))
     evalpoly(x, ch, false)
 end
 
diff --git a/test/ChebyshevT.jl b/test/ChebyshevT.jl
index 6f66e174..5b05b59a 100644
--- a/test/ChebyshevT.jl
+++ b/test/ChebyshevT.jl
@@ -16,6 +16,8 @@
         @test size(p, 1) == size(coeff, 1)
         @test typeof(p).parameters[2] == eltype(coeff)
         @test eltype(p) == eltype(coeff)
+
+        @test_throws DomainError p(2)
     end
 end