Mark non-intersecting types as nullable

[veewee]

This PR marks non-intersecting types as null whilst using the IntersectDuplicateTypesStrategy.

This results in nullable properties (getters, ...) during code generation with a default value of null.
So when the item is not available and you do try to access the property, you won't get an uninitialized error but null instead.

For example

    /**
     * @var null | string
     */
    private ?string $Time = null;

    /**
     * @return null | string
     */
    public function getTime() : ?string
    {
        return $this->Time;
    }

This means that your code needs to validate wether the value is present or not (at all times) before using non intersecting properties.

[veewee]

@rauanmayemir

I'm moving my service to v4 and thought this might be a sensible change.
Does it impact your services?

[rauanmayemir]

Does it just set default null value for nullable types?

I'm not sure if it's just my generator config, but I already have that in place, nullable types are already marked e.g like this:

    /**
     * Document number
     *
     * @var null | string
     */
    protected ?string $DocumentNum = null;

    /**
     * @return null | string
     */
    public function getDocumentNum() : ?string
    {
        return $this->DocumentNum;
    }

    /**
     * @param null | string $DocumentNum
     * @return $this
     */
    public function setDocumentNum(?string $DocumentNum) : static
    {
        $this->DocumentNum = $DocumentNum;
        return $this;
    }

[veewee]

@rauanmayemir it depends on how you configured code generation.
For nullable types, the code generation automatically sets this null default value.
However, you can control to do this for all properties by specifying PropertyAssemblerOptions::optionalValue

This PR is about when there are duplicate type-names and when you choose to intersect those types.
For example:

DuplicateType:

• a
• b

DuplicateType:

• a
• c

In this case the intersection will:

DuplicateType:

• a
• b -> always nullable
• c-> always nullable

I think your answer answered my question as well. :)

[rauanmayemir]

Indeed, I played with options and see that deliberately left out the optional value:

                    new Rules\AssembleRule(
                        new Assembler\PropertyAssembler(
                            Assembler\PropertyAssemblerOptions::create()
                                ->withVisibility(PropertyGenerator::VISIBILITY_PROTECTED)
//                                ->withOptionalValue()
                            ,
                        )
                    ),

It's odd that the default value is still applied.

[rauanmayemir]

Anyway, I can always tweak the generator and change the behavior if I need it to be different from default.

[veewee]

It's odd that the default value is still applied.

There is a overwrite during code generation for nullable types.
When a type is nullable, we always set the default to null (to avoid non initialized errors)