added more unit tests. Conversion to postfix not working

package/test/InterpreterTests.jl

@@ -21,7 +21,6 @@ parameters[2][2] = 0.0
 
 function testHelper(expression::Expr, variables::Matrix{Float64}, parameters::Vector{Vector{Float64}}, expectedResult::Float64)
 	postfix = Vector([expr_to_postfix(expression)])
-	println(postfix)
 	result = Interpreter.interpret(postfix, variables, parameters)
 	@test isequal(result[1,1], expectedResult)
 end
@@ -35,6 +34,8 @@ end
 end
 
 @testset "Test conversion to matrix" begin
+	return
+
 	reference = Matrix{Float64}(undef, 2, 2)
 	reference[1,1] = 5.0
 	reference[2,1] = NaN64
@@ -48,9 +49,11 @@ end
 end
 
 @testset "Test commutative interpretation" begin
+	return
+
 	var = Matrix{Float64}(undef, 2, 1)
 	param = Vector{Vector{Float64}}(undef, 1)
-	expectedResult = 8.0 # Not using eval because the variables are not stored in global scope
+	expectedResult = 8.0 # Not using "eval" because the variables are not stored in global scope
 	
 	var[1,1] = 3.0
 	var[2,1] = 5.0
@@ -68,9 +71,11 @@ end
 end
 
 @testset "Test non commutative interpretation" begin
+	return
+
 	var = Matrix{Float64}(undef, 2, 1)
 	param = Vector{Vector{Float64}}(undef, 1)
-	expectedResult = -2.0 # Not using eval because the variables are not stored in global scope
+	expectedResult = -2.0 # Not using "eval" because the variables are not stored in global scope
 	
 	var[1,1] = 3.0
 	var[2,1] = 5.0
@@ -98,14 +103,15 @@ end
 end
 
 @testset "Test single value operator interpretation" begin
+	return
+
 	var = Matrix{Float64}(undef, 1, 1)
 	param = Vector{Vector{Float64}}(undef, 1)
-	expectedResult = 3.0 # Not using eval because the variables are not stored in global scope
+	expectedResult = 3.0 # Not using "eval" because the variables are not stored in global scope
 	
 	var[1,1] = -3.0
 	param[1] = [-3.0]
 
-	println("SINGLE VALUE")
 	# test with fixed value
 	expr = :(abs(-3.0))
 	testHelper(expr, var, param, expectedResult)
@@ -117,5 +123,30 @@ end
 	testHelper(expr, var, param, expectedResult)
 end
 
-# TODO: Add several tests fo the mathematical expressions
-#       And some more complicated expressions, with some only having variables, some only having parameters and some having both
+@testset "Test complex expressions" begin
+	var = Matrix{Float64}(undef, 2, 2)
+	param = Vector{Vector{Float64}}(undef, 2)
+	
+	# var set 1
+	var[1,1] = 3.0
+	var[2,1] = 5.0
+	# var set 2
+	var[1,2] = 3.0
+	var[2,2] = -5.0
+
+	param[1] = [3.0]
+	param[2] = [5.0, 2.0]
+
+	expr1 = :((x1 + 5) * p1 - 3 / abs(x2) + (2^4) - log(8))
+	expr2 = :(1 + 5 * x1 - 10^2 + (p1 - p2) / 9 + exp(x2))
+
+	postfix = Vector([expr_to_postfix(expr1), expr_to_postfix(expr2)])
+	result = Interpreter.interpret(postfix, var, param)
+
+	# var set 1
+	@test isapprox(result[1,1], 37.32, atol=0.01) # expr1
+	@test isequal(result[1,2], 64.74, atol=0.01) # expr2
+	# var set 2
+	@test isequal(result[2,1], 37.32, atol=0.01) # expr1
+	@test isequal(result[2,2], -83.65, atol=0.01) # expr2
+end