From 8a416eb679662e7c1a8550749b611aa947fc8ba9 Mon Sep 17 00:00:00 2001
From: Sathvik Bhagavan <sathvikbhagavan@gmail.com>
Date: Thu, 28 Sep 2023 06:52:27 +0000
Subject: [PATCH] test: update tests for extrapolation

---
 test/derivative_tests.jl    | 4 +---
 test/interpolation_tests.jl | 6 ++++++
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/test/derivative_tests.jl b/test/derivative_tests.jl
index 3b3a1518..7501d096 100644
--- a/test/derivative_tests.jl
+++ b/test/derivative_tests.jl
@@ -3,11 +3,9 @@ using FiniteDifferences
 using DataInterpolations: derivative
 
 function test_derivatives(func, tspan, name::String)
-    trange = range(minimum(tspan), maximum(tspan), length = 32)[2:(end - 1)]
+    trange = range(minimum(tspan) - 5.0, maximum(tspan) + 5.0, length = 32)
     @testset "$name" begin
         for t in trange
-            # Linearly spaced points might lead to evaluations outside
-            # trange
             cdiff = central_fdm(5, 1; geom = true)(_t -> func(_t), t)
             adiff = derivative(func, t)
             @test isapprox(cdiff, adiff, atol = 1e-8)
diff --git a/test/interpolation_tests.jl b/test/interpolation_tests.jl
index 6ce3fefb..28ccdce4 100644
--- a/test/interpolation_tests.jl
+++ b/test/interpolation_tests.jl
@@ -476,21 +476,27 @@ u = [14.7, 11.51, 10.41, 14.95, 12.24, 11.22]
 
 A = BSplineInterpolation(u, t, 2, :Uniform, :Uniform)
 
+@test A(-1.0) == u[1]
 @test [A(25.0), A(80.0)] == [13.454197730061425, 10.305633616059845]
 @test [A(190.0), A(225.0)] == [14.07428439395079, 11.057784141519251]
 @test [A(t[1]), A(t[end])] == [u[1], u[end]]
+@test A(300.0) == u[end]
 
 A = BSplineInterpolation(u, t, 2, :ArcLen, :Average)
 
+@test A(-1.0) == u[1]
 @test [A(25.0), A(80.0)] == [13.363814458968486, 10.685201117692609]
 @test [A(190.0), A(225.0)] == [13.437481084762863, 11.367034741256463]
 @test [A(t[1]), A(t[end])] == [u[1], u[end]]
+@test A(300.0) == u[end]
 
 A = BSplineApprox(u, t, 2, 4, :Uniform, :Uniform)
 
+@test A(-1.0) == u[1]
 @test [A(25.0), A(80.0)] ≈ [12.979802931218234, 10.914310609953178]
 @test [A(190.0), A(225.0)] ≈ [13.851245975109263, 12.963685868886575]
 @test [A(t[1]), A(t[end])] ≈ [u[1], u[end]]
+@test A(300.0) == u[end]
 
 # Curvefit Interpolation
 rng = StableRNG(12345)