Fix isapprox for empty terms

src/functions.jl

@@ -301,9 +301,15 @@ function Base.isapprox(
     return f == g
 end
 
-# For affine and quadratic functions, terms are compressed in a dictionary using `_dicts` and then the dictionaries are compared with `dict_compare`
+# For affine and quadratic functions, terms are compressed in a dictionary using
+# `_dicts` and then the dictionaries are compared with `dict_compare`
 function dict_compare(d1::Dict, d2::Dict{<:Any,T}, compare::Function) where {T}
-    return all(kv -> compare(kv.second, Base.get(d2, kv.first, zero(T))), d1)
+    for key in union(keys(d1), keys(d2))
+        if !compare(Base.get(d1, key, zero(T)), Base.get(d2, key, zero(T)))
+            return false
+        end
+    end
+    return true
 end
 
 # Build a dictionary where the duplicate keys are summed

test/Bridges/Variable/zeros.jl

@@ -159,7 +159,7 @@ function test_zeros()
     s = """
     variables: x
     x >= 0.0
-    con1: x + 0.0 == 0.0
+    con1: 0.0 == 0.0
     con2: x + 0.0 >= 1.0
     minobjective: x
     """

test/FileFormats/SDPA/SDPA.jl

@@ -261,7 +261,7 @@ const _EXAMPLE_MODELS = [
         """
     variables: x, y
     minobjective: 10x + 20y
-    c1: [x + -1, 0, x + -2] in PositiveSemidefiniteConeTriangle(2)
+    c1: [x + -1, 0, x + y + -2] in PositiveSemidefiniteConeTriangle(2)
     c2: [5y + -3, 2y, 6y + -4] in PositiveSemidefiniteConeTriangle(2)
 """,
     ),
@@ -298,7 +298,7 @@ end
 function runtests()
     for name in names(@__MODULE__, all = true)
         if startswith("$(name)", "test_")
-            @testset "name" begin
+            @testset "$name" begin
                 getfield(@__MODULE__, name)()
             end
         end

test/functions.jl

@@ -110,6 +110,7 @@ function test_isapprox_SingleVariable()
     y = MOI.VariableIndex(2)
     @test MOI.SingleVariable(x) == MOI.SingleVariable(x)
     @test MOI.SingleVariable(x) != MOI.SingleVariable(y)
+    return
 end
 
 function test_isapprox_VectorOfVariables()
@@ -119,6 +120,7 @@ function test_isapprox_VectorOfVariables()
     @test MOI.VectorOfVariables([y, x]) != MOI.VectorOfVariables([x, y])
     @test MOI.VectorOfVariables([x, x]) != MOI.VectorOfVariables([x])
     @test MOI.VectorOfVariables([x]) != MOI.VectorOfVariables([y])
+    return
 end
 
 function test_isapprox_ScalarAffineFunction()
@@ -137,8 +139,11 @@ function test_isapprox_ScalarAffineFunction()
     f = MOI.ScalarAffineFunction(MOI.ScalarAffineTerm.([2, 4], [x, y]), 6)
     g = deepcopy(f)
     @test g ≈ f
+    @test f ≈ g
     f.terms[2] = MOI.ScalarAffineTerm(3, y)
     @test !(g ≈ f)
+    @test !(f ≈ g)
+    return
 end
 
 function test_isapprox_VectorAffineFunction()
@@ -155,8 +160,11 @@ function test_isapprox_VectorAffineFunction()
     @test f ≈ g
     f.terms[3] = MOI.VectorAffineTerm(2, MOI.ScalarAffineTerm(9, y))
     @test !(f ≈ g)
+    @test !(g ≈ f)
     push!(f.terms, MOI.VectorAffineTerm(2, MOI.ScalarAffineTerm(-6, y)))
     @test f ≈ g
+    @test g ≈ f
+    return
 end
 
 function test_isapprox_ScalarQuadraticFunction()
@@ -175,8 +183,11 @@ function test_isapprox_ScalarQuadraticFunction()
     g = deepcopy(f)
     push!(f.quadratic_terms, MOI.ScalarQuadraticTerm(2, y, x))
     @test !(f ≈ g)
+    @test !(g ≈ f)
     push!(f.quadratic_terms, MOI.ScalarQuadraticTerm(-2, y, x))
     @test f ≈ g
+    @test g ≈ f
+    return
 end
 
 function test_isapprox_VectorQuadraticFunction()
@@ -196,14 +207,47 @@ function test_isapprox_VectorQuadraticFunction()
     )
     g = deepcopy(f)
     @test f ≈ g
+    @test g ≈ f
     f.affine_terms[1] = MOI.VectorAffineTerm(3, MOI.ScalarAffineTerm(4, x))
     @test !(f ≈ g)
+    @test !(g ≈ f)
     push!(g.affine_terms, MOI.VectorAffineTerm(1, MOI.ScalarAffineTerm(-3, x)))
     push!(g.affine_terms, MOI.VectorAffineTerm(3, MOI.ScalarAffineTerm(4, x)))
     @test f ≈ g
+    @test g ≈ f
     f.quadratic_terms[1] =
         MOI.VectorQuadraticTerm(3, MOI.ScalarQuadraticTerm(1, x, x))
     @test !(f ≈ g)
+    @test !(g ≈ f)
+    return
+end
+
+function test_isapprox_issue_1483()
+    x = MOI.ScalarQuadraticFunction(
+        MOI.ScalarAffineTerm{Float16}[],
+        MOI.ScalarQuadraticTerm{Float16}[],
+        Float16(0.0),
+    )
+    y = MOI.ScalarQuadraticFunction(
+        MOI.ScalarAffineTerm{Float16}[MOI.ScalarAffineTerm(
+            Float16(1.0),
+            MOI.VariableIndex(1234),
+        )],
+        MOI.ScalarQuadraticTerm{Float16}[],
+        Float16(0.0),
+    )
+    z = MOI.ScalarQuadraticFunction(
+        MOI.ScalarAffineTerm{Float16}[],
+        MOI.ScalarQuadraticTerm{Float16}[],
+        Float16(0.0),
+    )
+    @test !(x ≈ y)
+    @test !(y ≈ x)
+    @test x ≈ z
+    @test z ≈ x
+    @test !(y ≈ z)
+    @test !(z ≈ y)
+    return
 end
 
 function runtests()