From 9a93f0e9d789ce49d29cdd5b05284a0db8f2ba50 Mon Sep 17 00:00:00 2001
From: odow <o.dowson@gmail.com>
Date: Thu, 12 Oct 2023 15:15:03 +0200
Subject: [PATCH] Restrict rhs to Bool

---
 src/constraints.jl      | 25 +++++++++----------
 test/test_constraint.jl | 54 ++++++++---------------------------------
 2 files changed, 21 insertions(+), 58 deletions(-)

diff --git a/src/constraints.jl b/src/constraints.jl
index 5db80f7ca12..dcb76d0d1c1 100644
--- a/src/constraints.jl
+++ b/src/constraints.jl
@@ -1549,25 +1549,22 @@ end
 
 model_convert(::AbstractModel, set::_DoNotConvertSet) = set
 
-function moi_set(constraint::ScalarConstraint{F,<:_DoNotConvertSet}) where {F}
-    return constraint.set.set
-end
-
-function _build_boolean_equal_to(::Function, lhs, rhs)
-    set = _DoNotConvertSet(MOI.EqualTo(true))
-    return ScalarConstraint(op_equal_to(lhs, rhs), set)
-end
+moi_set(c::ScalarConstraint{F,<:_DoNotConvertSet}) where {F} = c.set.set
 
-function _build_boolean_equal_to(::Function, lhs::Bool, rhs)
-    return ScalarConstraint(rhs, _DoNotConvertSet(MOI.EqualTo(lhs)))
+function _build_boolean_equal_to(::Function, lhs::AbstractJuMPScalar, rhs::Bool)
+    return ScalarConstraint(lhs, _DoNotConvertSet(MOI.EqualTo(rhs)))
 end
 
-function _build_boolean_equal_to(::Function, lhs, rhs::Bool)
-    return ScalarConstraint(lhs, _DoNotConvertSet(MOI.EqualTo(rhs)))
+function _build_boolean_equal_to(error_fn::Function, ::AbstractJuMPScalar, rhs)
+    return error_fn(
+        "cannot add the `:=` constraint. The right-hand side must be a `Bool`",
+    )
 end
 
-function _build_boolean_equal_to(error_fn::Function, lhs::Bool, rhs::Bool)
-    return error_fn("cannot add the trivial constraint `$lhs := $rhs`")
+function _build_boolean_equal_to(error_fn::Function, lhs, ::Any)
+    return error_fn(
+        "cannot add the `:=` constraint with left-hand side of type `::$(typeof(lhs))`",
+    )
 end
 
 function parse_constraint_head(error_fn::Function, ::Val{:(:=)}, lhs, rhs)
diff --git a/test/test_constraint.jl b/test/test_constraint.jl
index 02e5dd009e8..de98fd8b331 100644
--- a/test/test_constraint.jl
+++ b/test/test_constraint.jl
@@ -1721,14 +1721,11 @@ function test_triangle_vec()
     return
 end
 
-function test_def_equal_to_operator()
-    model = GenericModel{Bool}()
+function _test_def_equal_to_operator_T(::Type{T}) where {T}
+    model = GenericModel{T}()
     @variable(model, x[1:3])
     # x[1] := x[2]
-    c = @constraint(model, x[1] := x[2])
-    o = constraint_object(c)
-    @test isequal_canonical(o.func, op_equal_to(x[1], x[2]))
-    @test o.set == MOI.EqualTo(true)
+    @test_throws ErrorException @constraint(model, x[1] := x[2])
     # x[1] == x[2] := false
     c = @constraint(model, x[1] == x[2] := false)
     o = constraint_object(c)
@@ -1752,48 +1749,17 @@ function test_def_equal_to_operator()
     @test o.set == MOI.EqualTo(y)
     # y := x[1] || x[2]
     y = true
-    c = @constraint(model, y := x[1] || x[2])
-    o = constraint_object(c)
-    @test isequal_canonical(o.func, op_or(x[1], x[2]))
-    @test o.set == MOI.EqualTo(y)
+    @test_throws ErrorException @constraint(model, y := x[1] || x[2])
     return
 end
 
 function test_def_equal_to_operator_float()
-    model = Model()
-    @variable(model, x[1:3])
-    # x[1] := x[2]
-    c = @constraint(model, x[1] := x[2])
-    o = constraint_object(c)
-    @test isequal_canonical(o.func, op_equal_to(x[1], x[2]))
-    @test o.set == MOI.EqualTo(true)
-    # x[1] == x[2] := false
-    c = @constraint(model, x[1] == x[2] := false)
-    o = constraint_object(c)
-    @test isequal_canonical(o.func, op_equal_to(x[1], x[2]))
-    @test o.set == MOI.EqualTo(false)
-    # x[1] && x[2] := false
-    c = @constraint(model, x[1] && x[2] := false)
-    o = constraint_object(c)
-    @test isequal_canonical(o.func, op_and(x[1], x[2]))
-    @test o.set == MOI.EqualTo(false)
-    # x[1] && x[2] := true
-    c = @constraint(model, x[1] && x[2] := true)
-    o = constraint_object(c)
-    @test isequal_canonical(o.func, op_and(x[1], x[2]))
-    @test o.set == MOI.EqualTo(true)
-    # x[1] || x[2] := y
-    y = true
-    c = @constraint(model, x[1] || x[2] := y)
-    o = constraint_object(c)
-    @test isequal_canonical(o.func, op_or(x[1], x[2]))
-    @test o.set == MOI.EqualTo(true)
-    # y := x[1] || x[2]
-    y = true
-    c = @constraint(model, y := x[1] || x[2])
-    o = constraint_object(c)
-    @test isequal_canonical(o.func, op_or(x[1], x[2]))
-    @test o.set == MOI.EqualTo(true)
+    _test_def_equal_to_operator_T(Float64)
+    return
+end
+
+function test_def_equal_to_operator_bool()
+    _test_def_equal_to_operator_T(Bool)
     return
 end