test(BaseParams): add unit tests for calc_wirearray_gmr

Author: amaurigmartins

test/unit_BaseParams/test_calc_wirearray_gmr.jl

@@ -0,0 +1,99 @@
+@testitem "calc_wirearray_gmr unit tests" setup = [defaults] begin
+    using Measurements: measurement, value, uncertainty
+
+    @testset "Basic Functionality" begin
+        # Example from docstring
+        lay_rad = 0.05
+        N = 7
+        rad_wire = 0.002
+        mu_r = 1.0
+        gmr = calc_wirearray_gmr(lay_rad, N, rad_wire, mu_r)
+        expected = exp((log(rad_wire * exp(-mu_r / 4) * N * lay_rad^(N - 1)) / N))
+        @test isapprox(gmr, expected; atol=TEST_TOL)
+        @test gmr > 0
+    end
+
+    @testset "Edge Cases" begin
+        # N = 1 (single wire)
+        lay_rad = 0.05
+        N = 1
+        rad_wire = 0.002
+        mu_r = 1.0
+        gmr = calc_wirearray_gmr(lay_rad, N, rad_wire, mu_r)
+        expected = rad_wire * exp(-mu_r / 4)
+        @test isapprox(gmr, expected; atol=TEST_TOL)
+
+        # mu_r = 0 (non-magnetic)
+        lay_rad = 0.05
+        N = 7
+        rad_wire = 0.002
+        mu_r = 0.0
+        gmr = calc_wirearray_gmr(lay_rad, N, rad_wire, mu_r)
+        expected = exp((log(rad_wire * N * lay_rad^(N - 1)) / N))
+        @test isapprox(gmr, expected; atol=TEST_TOL)
+
+        # rad_wire = 0 (degenerate wire)
+        lay_rad = 0.05
+        N = 7
+        rad_wire = 0.0
+        mu_r = 1.0
+        gmr = calc_wirearray_gmr(lay_rad, N, rad_wire, mu_r)
+        @test gmr == 0.0
+
+        # lay_rad = 0 (all wires at center)
+        lay_rad = 0.0
+        N = 7
+        rad_wire = 0.002
+        mu_r = 1.0
+        gmr = calc_wirearray_gmr(lay_rad, N, rad_wire, mu_r)
+        expected = exp((log(rad_wire * exp(-mu_r / 4) * N * 0.0^(N - 1)) / N))
+        @test gmr == 0.0
+    end
+
+    @testset "Numerical Consistency" begin
+        # Float64
+        gmr1 = calc_wirearray_gmr(0.05, 7, 0.002, 1.0)
+        # Measurement{Float64}
+        gmr2 = calc_wirearray_gmr(measurement(0.05, 1e-4), 7, 0.002, 1.0)
+        @test isapprox(value(gmr2), gmr1; atol=TEST_TOL)
+        @test uncertainty(gmr2) > 0
+    end
+
+    @testset "Physical Behavior" begin
+        # GMR increases with lay_rad
+        gmr1 = calc_wirearray_gmr(0.01, 7, 0.002, 1.0)
+        gmr2 = calc_wirearray_gmr(0.05, 7, 0.002, 1.0)
+        @test gmr2 > gmr1
+        # GMR decreases with mu_r
+        gmr1 = calc_wirearray_gmr(0.05, 7, 0.002, 0.5)
+        gmr2 = calc_wirearray_gmr(0.05, 7, 0.002, 2.0)
+        @test gmr2 < gmr1
+    end
+
+    @testset "Type Stability & Promotion" begin
+        # All Float64
+        gmr = calc_wirearray_gmr(0.05, 7, 0.002, 1.0)
+        @test typeof(gmr) == Float64
+        # All Measurement
+        gmr = calc_wirearray_gmr(measurement(0.05, 1e-4), 7, measurement(0.002, 1e-5), measurement(1.0, 0.01))
+        @test gmr isa Measurement{Float64}
+        # Mixed: lay_rad as Measurement
+        gmr = calc_wirearray_gmr(measurement(0.05, 1e-4), 7, 0.002, 1.0)
+        @test gmr isa Measurement{Float64}
+        # Mixed: rad_wire as Measurement
+        gmr = calc_wirearray_gmr(0.05, 7, measurement(0.002, 1e-5), 1.0)
+        @test gmr isa Measurement{Float64}
+        # Mixed: mu_r as Measurement
+        gmr = calc_wirearray_gmr(0.05, 7, 0.002, measurement(1.0, 0.01))
+        @test gmr isa Measurement{Float64}
+    end
+
+    @testset "Uncertainty Quantification" begin
+        lay_rad = measurement(0.05, 1e-4)
+        rad_wire = measurement(0.002, 1e-5)
+        mu_r = measurement(1.0, 0.01)
+        gmr = calc_wirearray_gmr(lay_rad, 7, rad_wire, mu_r)
+        @test gmr isa Measurement{Float64}
+        @test uncertainty(gmr) > 0
+    end
+end