fix unable to add markers when autoSize chart option is enabled

[victorbrambati]

Type of PR: bugfix

PR checklist:

• Addresses an existing issue: fixes Inability to immediately add markers when autoSize chart option is enabled #1271
• Includes tests
• N/A Documentation update

Overview of change:

• The function timeScale.isEmpty() was returning true. This because there a condition with a width === 0. To resolve this issue, an initial size was added so that the markers could be recalculated.
• I changed the condition of _recalculateMarkers() to be easier to read.

Glitch Code Sandbox link:
https://glitch.com/edit/#!/hurricane-mahogany-output

[SlicedSilver]

@victorbrambati Thank you for your PR.
Having a quick look at the graphics-tests it appears that this additional fixes another bug I've noticed regarding the initial render not having the correct right offset (the last few bars aren't visible).

We will conduct the code review and QA process before merging, but this will hopefully be done soon.

[victorbrambati]

@SlicedSilver Surprising! Any changes that you need, you can reply me.

[SlicedSilver]

@victorbrambati I also think it would be good to have a graphics e2e test case which covers this bug.
Is this something that you would like to work on? or would you prefer me to add the test to your PR?

I'm happy to do it but wanted to check first if you wanted to work on this.

[victorbrambati]

@SlicedSilver Yes I want work on it.

[SlicedSilver]

@SlicedSilver Yes I want work on it.

Great :) Thank you.

Here is a some documentation on the graphics tests: https://github.com/tradingview/lightweight-charts/tree/master/tests#graphics

You essentially just need to make a .js file inside this folder: tests/e2e/graphics/test-cases

There are some examples there which you can use for inspiration, and you could do something similar to the Glitch example on the bug report.

[SlicedSilver]

Thank you @victorbrambati
The tests look good. You can clearly see that it failed on the current release (v4.0.0) and is fixed on your branch.

Golden:

Test:

[victorbrambati]

@SlicedSilver You're welcome.
This test too work to issue #1282 because the priceline is different.