Merge pull request #1929 from contradict/validate-connection

Add unit validation for Connections

Author: YingboMa

src/systems/validation.jl

@@ -29,12 +29,12 @@ MT = ModelingToolkit
 ```
 """
 equivalent(x, y) = isequal(1 * x, 1 * y)
-unitless = Unitful.unit(1)
+const unitless = Unitful.unit(1)
 
 #For dispatching get_unit
-Literal = Union{Sym, Symbolics.ArrayOp, Symbolics.Arr, Symbolics.CallWithMetadata}
-Conditional = Union{typeof(ifelse), typeof(IfElse.ifelse)}
-Comparison = Union{typeof.([==, !=, ≠, <, <=, ≤, >, >=, ≥])...}
+const Literal = Union{Sym, Symbolics.ArrayOp, Symbolics.Arr, Symbolics.CallWithMetadata}
+const Conditional = Union{typeof(ifelse), typeof(IfElse.ifelse)}
+const Comparison = Union{typeof.([==, !=, ≠, <, <=, ≤, >, >=, ≥])...}
 
 "Find the unit of a symbolic item."
 get_unit(x::Real) = unitless
@@ -170,6 +170,37 @@ function _validate(terms::Vector, labels::Vector{String}; info::String = "")
     valid
 end
 
+function _validate(conn::Connection; info::String = "")
+    valid = true
+    syss = get_systems(conn)
+    sys = first(syss)
+    st = states(sys)
+    for i in 2:length(syss)
+        s = syss[i]
+        sst = states(s)
+        if length(st) != length(sst)
+            valid = false
+            @warn("$info: connected systems $(nameof(sys)) and $(nameof(s)) have $(length(st)) and $(length(sst)) states, cannor connect.")
+            continue
+        end
+        for (i, x) in enumerate(st)
+            j = findfirst(isequal(x), sst)
+            if j == nothing
+                valid = false
+                @warn("$info: connected systems $(nameof(sys)) and $(nameof(s)) do not have the same states.")
+            else
+                aunit = safe_get_unit(x, info * string(nameof(sys)) * "#$i")
+                bunit = safe_get_unit(sst[j], info * string(nameof(s)) * "#$j")
+                if !equivalent(aunit, bunit)
+                    valid = false
+                    @warn("$info: connected system states $x and $(sst[j]) have mismatched units.")
+                end
+            end
+        end
+    end
+    valid
+end
+
 function validate(jump::Union{ModelingToolkit.VariableRateJump,
                               ModelingToolkit.ConstantRateJump}, t::Symbolic;
                   info::String = "")
@@ -195,7 +226,11 @@ function validate(jumps::ArrayPartition{<:Union{Any, Vector{<:JumpType}}}, t::Sy
 end
 
 function validate(eq::ModelingToolkit.Equation; info::String = "")
-    _validate([eq.lhs, eq.rhs], ["left", "right"]; info)
+    if typeof(eq.lhs) == Connection
+        _validate(eq.rhs; info)
+    else
+        _validate([eq.lhs, eq.rhs], ["left", "right"]; info)
+    end
 end
 function validate(eq::ModelingToolkit.Equation,
                   term::Union{Symbolic, Unitful.Quantity, Num}; info::String = "")

test/units.jl

@@ -62,6 +62,36 @@ ODESystem(eqs, name = :sys, checks = false)
 @test_throws MT.ValidationError ODESystem(eqs, t, [E, P, t], [τ], name = :sys,
                                           checks = MT.CheckUnits)
 
+# connection validation
+@connector function Pin(; name)
+    sts = @variables(v(t)=1.0, [unit = u"V"],
+                     i(t)=1.0, [unit = u"A", connect = Flow])
+    ODESystem(Equation[], t, sts, []; name = name)
+end
+@connector function OtherPin(; name)
+    sts = @variables(v(t)=1.0, [unit = u"mV"],
+                     i(t)=1.0, [unit = u"mA", connect = Flow])
+    ODESystem(Equation[], t, sts, []; name = name)
+end
+@connector function LongPin(; name)
+    sts = @variables(v(t)=1.0, [unit = u"V"],
+                     i(t)=1.0, [unit = u"A", connect = Flow],
+                     x(t)=1.0, [unit = NoUnits])
+    ODESystem(Equation[], t, sts, []; name = name)
+end
+@named p1 = Pin()
+@named p2 = Pin()
+@named op = OtherPin()
+@named lp = LongPin()
+good_eqs = [connect(p1, p2)]
+bad_eqs = [connect(p1, p2, op)]
+bad_length_eqs = [connect(op, lp)]
+@test MT.validate(good_eqs)
+@test !MT.validate(bad_eqs)
+@test !MT.validate(bad_length_eqs)
+@named sys = ODESystem(good_eqs, t, [], [])
+@test_throws MT.ValidationError ODESystem(bad_eqs, t, [], []; name = :sys)
+
 # Array variables
 @variables t [unit = u"s"] x(t)[1:3] [unit = u"m"]
 @parameters v[1:3]=[1, 2, 3] [unit = u"m/s"]