Fix tests

Author: YingboMa

src/utils.jl

@@ -808,8 +808,8 @@ end
 
 function fold_constants(ex)
     if istree(ex)
-        similarterm(ex, operations(ex), map(fold_constants, arguments(ex)),
-                    symtype(expr); metadata = metadata(expr))
+        similarterm(ex, operation(ex), map(fold_constants, arguments(ex)),
+                    symtype(ex); metadata = metadata(ex))
     elseif issym(ex) && isconstant(ex)
         getdefault(ex)
     else

test/constants.jl

@@ -30,11 +30,7 @@ MT.get_unit(β)
 @variables t [unit = u"s"] x(t) [unit = u"m"]
 D = Differential(t)
 eqs = [D(x) ~ β]
-sys = ODESystem(eqs, name = :sys)
-# Note that the equation won't unit-check now
-#    b/c the literal value doesn't have units on it
-#    Testing that units checking is bypassed in the constructors
+@named sys = ODESystem(eqs)
 simp = structural_simplify(sys)
-@test_throws MT.ValidationError MT.check_units(simp.eqs...)
 
 @test isempty(MT.collect_constants(nothing))