Bug 240103 – flex-basis wont transition if a value is percentage

• Component: Animations
• Status: NEW

MacOs 12.2.1 (safari 15.3) / iPad OS 15.0

Percentages in flex-basis cause transition to stop working.

The following used to work and still does on other browsers:

```
div {
  flex-basis: min(200px, 33%);
  transition: all ease-out .25s;
}
div:hover {
  flex-basis: 300px;
}
```

The problem isn't with using min because:

The following also doesnt work:

```
div {
  flex-basis: 33%;
  transition: all ease-out .25s;
}
div:hover {
  flex-basis: 300px;
}
```

While this does:

```
div {
  flex-basis: flex-basis: min(200px,500px);
  transition: all ease-out .25s;
}
div:hover {
  flex-basis: 300px;
}
```

Also using the 1st example and width instead of flex-basis transitions fine even tho the min contains a percentage

[Antoine Quint]

Thanks for filing this report. Could you write a complete testcase that shows the regression here?

[Radar WebKit Bug Importer]

<rdar://problem/93090931>

[Antoine Quint]

Could you also check with Safari Technology Preview if you can still reproduce the issue?

I've attempted to write a simple demo that transitions flex-basis from a percentage value to a px value and it worked fine for me.