fix: Size for SpriteComponent.fromImage should be nullable

[fa-fifi]

Description

I received an assertion error after I set autoResize to true when I am using SpriteComponent.fromImage component. It's kinda weird for me that the message tells me "If size is set, autoResize should be false or size should be null when autoResize is true.'', but the thing is I never set the size for that image yet. Then, I check the code and I found out that the size will never be null anyway, so the autoresize should always be false.

In this PR, I just remove all the fallback value for size, so it would not give an assertion error when size is not being set yet while the autoresize is true.

Checklist

• I have followed the Contributor Guide when preparing my PR.
• I have updated/added tests for ALL new/updated/fixed functionality.
• I have updated/added relevant documentation in docs and added dartdoc comments with ///.
• I have updated/added relevant examples in examples or docs.

Breaking Change?

• No, this PR is not a breaking change.

[ufrshubham]

I think SpriteComponent.fromImage should not explicitly set size as srcSize or image.size. So something like this should be enough.

Suggested change

	size: size ?? srcSize ?? image.size,
	size: size,

[spydon]

What's the reason for that? Then it'll have a different behavior than the other constructor right? 🤔

[ufrshubham]

Not really. SpriteComponent.fromImage internally invokes the same constructor.

flame/packages/flame/lib/src/components/sprite_component.dart

Line 69 in e434baf

}) : this(

[spydon]

Ah, that makes a lot of sense then!

[fa-fifi]

So... should I commit changes based on @ufrshubham's suggestion?

[spydon]

Yeah, please do

[ufrshubham]

Yup, commit that change and then autoResize can be left as it was earlier.

[ufrshubham]

@fa-fifi can you update the title and description of the PR to be inline with what it actually does. Also, some tests for SpriteComponent.fromImage would be good.

[fa-fifi]

I have updated the title and the description for this PR. Feel free to edit them if you think they are not suitable since English is not my mother tongue.

There are some other stuff that I have to focus on rn, so I'll revisit this PR again in the next couple days to update the test cases for SpriteComponent.fromImage. You can help me with test cases if you want.