test: Adding testing for new function

src/PowerSystems.jl

@@ -390,6 +390,9 @@ export get_compression_settings
 export CompressionSettings
 export CompressionTypes
 
+# Parsing functions
+export create_poly_cost
+
 #export make_time_series
 export get_bus_numbers
 export get_name

test/test_power_system_table_data.jl

@@ -181,3 +181,51 @@ end
     g = get_components(ThermalStandard, sys)
     @test get_variable.(get_operation_cost.(g)) == get_variable.(get_operation_cost.(g))
 end
+
+@testset "Test create_poly_cost function" begin
+
+    cost_colnames = ["heat_rate_a0", "heat_rate_a1", "heat_rate_a2"]
+
+    # Coefficients for a CC using natura gas
+    a2 = -0.000531607
+    a1 = 0.060554675
+    a0 = 8.951100118
+
+    # First test that return quadratic if all coefficients are provided.
+    # We convert the coefficients to string to mimic parsing from csv
+    example_generator = (name="test-gen", heat_rate_a0=string(a0), heat_rate_a1=string(a1), heat_rate_a2=string(a2))
+    cost_curve, fixed_cost = create_poly_cost(example_generator, cost_colnames)
+    @assert cost_curve isa QuadraticCurve
+    @assert isapprox(get_quadratic_term(cost_curve), a2, atol=0.01)
+    @assert isapprox(get_proportional_term(cost_curve), a1, atol=0.01)
+    @assert isapprox(get_constant_term(cost_curve), a0, atol=0.01)
+
+    # Test return linear with both proportional and constant term
+    example_generator = (name="test-gen", heat_rate_a0=string(a0), heat_rate_a1=string(a1), heat_rate_a2=nothing)
+    cost_curve, fixed_cost = create_poly_cost(example_generator, cost_colnames)
+    @assert cost_curve isa LinearCurve
+    @assert isapprox(get_proportional_term(cost_curve), a1, atol=0.01)
+    @assert isapprox(get_constant_term(cost_curve), a0, atol=0.01)
+
+    # Test return linear with just proportional term
+    example_generator = (name="test-gen", heat_rate_a0=nothing, heat_rate_a1=string(a1), heat_rate_a2=nothing)
+    cost_curve, fixed_cost = create_poly_cost(example_generator, cost_colnames)
+    @assert cost_curve isa LinearCurve
+    @assert isapprox(get_proportional_term(cost_curve), a1, atol=0.01)
+
+    # Test raises error if a2 is passed but other coefficients are nothing
+    example_generator = (name="test-gen", heat_rate_a0=nothing, heat_rate_a1=nothing, heat_rate_a2=string(a2))
+    @test_throws IS.DataFormatError create_poly_cost(example_generator, cost_colnames)
+    example_generator = (name="test-gen", heat_rate_a0=nothing, heat_rate_a1=string(a1), heat_rate_a2=string(a2))
+    @test_throws IS.DataFormatError create_poly_cost(example_generator, cost_colnames)
+    example_generator = (name="test-gen", heat_rate_a0=string(a0), heat_rate_a1=nothing, heat_rate_a2=string(a2))
+    @test_throws IS.DataFormatError create_poly_cost(example_generator, cost_colnames)
+
+    # Test that it works with zero proportional and constant term
+    example_generator = (name="test-gen", heat_rate_a0=string(0.0), heat_rate_a1=string(0.0), heat_rate_a2=string(a2))
+    cost_curve, fixed_cost = create_poly_cost(example_generator, cost_colnames)
+    @assert cost_curve isa QuadraticCurve
+    @assert isapprox(get_quadratic_term(cost_curve), a2, atol=0.01)
+    @assert isapprox(get_proportional_term(cost_curve), 0.0, atol=0.01)
+    @assert isapprox(get_constant_term(cost_curve), 0.0, atol=0.01)
+end