fix and test broadcast promotedims (#918)

Author: rafaqz

src/Lookups/lookup_arrays.jl

@@ -852,21 +852,23 @@ promote_first(x1, x2, xs...) =
 # Fallback NoLookup if not identical type
 promote_first(l1::Lookup) = l1
 promote_first(l1::L, ls::L...) where L<:Lookup = rebuild(l1; metadata=NoMetadata)
-function promote_first(l1::L, ls::Lookup...) where {L<:Lookup} 
-    ls = _remove(Length1NoLookup, l1, ls...)
-    if length(ls) > 1 
-        l1, ls... = ls
-    else
+function promote_first(l1::Lookup, ls1::Lookup...)
+    ls = _remove(Length1NoLookup, l1, ls1...)
+    if length(ls) != length(ls1) + 1
+        # If anything was removed, start again
+        return promote_first(ls...)
+    elseif length(ls) == 1
+        # If there is only one left, use it
         return first(ls)
     end
-    if all(map(l -> typeof(l) == L, ls))
-        if length(ls) > 0
-            rebuild(l1; metadata=NoMetadata())
-        else
-            l1 # Keep metadata if there is only one lookup
-        end
+    # Otherwise see if these have the same type
+    l2, ls2... = ls
+    if all(map(l -> typeof(l) == typeof(l2), ls2))
+        # If so, just simplify the metadata
+        rebuild(l2; metadata=NoMetadata())
     else
-        NoLookup(Base.OneTo(length(l1)))
+        # And if not, use NoLookup
+        NoLookup(Base.OneTo(length(l2)))
     end
 end
 # Categorical lookups

src/array/broadcast.jl

@@ -174,7 +174,9 @@ macro d(expr::Expr, options::Union{Expr,Nothing}=nothing)
             dims = $DimensionalData.dims(found_dims, order_dims)
         end
     else
-        :(dims = _find_dims(vars))
+        quote
+            dims = _find_dims(vars)
+        end
     end
     quote
         let
@@ -404,7 +406,6 @@ _broadcasted_dims(a) = ()
 # its dimensions to match the rest of the @d broadcast, otherwise do nothing.
 _maybe_dimensional_broadcast(x, _, _) = x
 function _maybe_dimensional_broadcast(A::AbstractBasicDimArray, dest_dims, options) 
-    len1s = basedims(otherdims(dest_dims, dims(A)))
     # Reshape first to avoid a ReshapedArray wrapper if possible
     A1 = _maybe_insert_length_one_dims(A, dest_dims)
     # Then permute and reorder

test/broadcast.jl

@@ -371,6 +371,21 @@ end
             p(da1, da2, permutedims(da3, (X, Y, Z)))
     end
 
+    @testset "Lookups are maintained" begin
+        x = format(X(-5.0:5.0))
+        y = format(Y(-10.0:2:12.0))
+        z = format(Z(-3.0:0.5:4.0))
+
+        u = @d x .* y
+        v = @d x .* z
+        w = @d y .* z
+
+        f(u, v, w) = u + v + w
+
+        A = @d f.(u, v, w)
+        @test dims(A) == (x, y, z)
+    end
+
     @testset "strict" begin
         @test_nowarn @d rand(X(1:3)) .* rand(X([:a, :b, :c])) strict=false
         @test_throws DimensionMismatch @d rand(X(1:3)) .* rand(X([:a, :b, :c])) strict=true