add more tests

Author: Alessandro

test/egraph.jl

@@ -3,13 +3,17 @@ using SymbolicUtils
 sym_eq(x, y) = simplify(x == y)
 (≖)(x, y) = sym_eq(x,y)
 
-@syms a b
-ex = 2a + 2b - (a*(a + b))
-res = optimize(ex)
-@test res ≖ (a+b)*(2-a)
+@syms a b c x
+@testset "Basic optimization" begin 
+    ex = 2a + 2b - (a*(a + b))
+    res = optimize(ex)
+    @test res ≖ (a+b)*(2-a)
 
+    ex = sin(a^2)/cos(a^2)
+    res = optimize(ex)
+    @test isequal(res, tan(a^2)) # sym_eq does not work
 
-# TODO test metadata
-ex = sin(a^2)/cos(a^2)
-res = optimize(ex)
-@test isequal(res, tan(a^2)) # sym_eq does not work
+    ex = sin(1/x * (a * b + a * c))^2 + cos((a*(b+c))/x)^2
+    res = optimize(ex)
+    @test res == 1
+end