Test support for VariablePrimalStart in Bridges.Variable

[odow]

x-ref #2115

This is actually a rabbit hole that I'm yet to make my way out of...

[odow]

I've opted-out here, since setting or getting the start can't be done in isolation.

[blegat]

Yes, this is part of the optional API. By the way, this should be default as in

MathOptInterface.jl/src/Bridges/bridge.jl

Lines 105 to 149 in 5025b50

	"""
	MOI.supports(
	model::MOI.ModelLike,
	attr::MOI.AbstractConstraintAttribute,
	BT::Type{<:AbstractBridge},
	)
	Return a `Bool` indicating whether `BT` supports setting `attr` to `model`.
	"""
	function MOI.supports(
	::MOI.ModelLike,
	::MOI.AbstractConstraintAttribute,
	::Type{<:AbstractBridge},
	)
	return false
	end
	"""
	function MOI.get(
	model::MOI.ModelLike,
	attr::MOI.AbstractConstraintAttribute,
	bridge::AbstractBridge,
	)
	Return the value of the attribute `attr` of the model `model` for the
	constraint bridged by `bridge`.
	"""
	function MOI.get(
	::MOI.ModelLike,
	attr::MOI.AbstractConstraintAttribute,
	bridge::AbstractBridge,
	)
	return throw(
	ArgumentError(
	"Bridge of type `$(typeof(bridge))` does not support accessing " *
	"the attribute `$attr`. If you encountered this error " *
	"unexpectedly, it probably means your model has been " *
	"reformulated using the bridge, and you are attempting to query " *
	"an attribute that we haven't implemented yet for this bridge. " *
	"Please open an issue at https://github.com/jump-dev/MathOptInterface.jl/issues/new " *
	"and provide a reproducible example explaining what you were " *
	"trying to do.",
	),
	)
	end

[blegat]

Bridges should have to implement it to return false

[blegat]

I've opted-out here, since setting or getting the start can't be done in isolation.

I understand what you mean now, so I reverted back to your solution and opened #2117

[blegat]

We supports, we prefer false positive than false negative. Previously, there were false positive but here, there might be false negative in case not all variables are set.

[odow]

Happy?

[blegat]

Yes, I just wanted to let you take a look