This patch implements a new image comparison function, codenamed
"ssim-cie94". The goal of the new comparison function is to cancel out
browser non-determenistic rendering.
To use the new comparison function:
```ts
await expect(page).toHaveScreenshot({
comparator: 'ssim-cie94',
});
```
As of Nov 30, 2022, we identified the following sources of
non-determenistic rendering for Chromium:
- Anti-aliasing for certain shapes might be different due to the
way skia rasterizes certain shapes.
- Color blending might be different on `x86` and `aarch64`
architectures.
The new function employs a few heuristics to fight these
differences.
Consider two non-equal image pixels `(r1, g1, b1)` and `(r2, g2, b2)`:
1. If the [CIE94] metric is less then 1.0, then we consider these pixels
**EQUAL**. (The value `1.0` is the [just-noticeable difference] for
[CIE94].). Otherwise, proceed to next step.
1. If all the 8 neighbors of the first pixel match its color, or
if the 8 neighbors of the second pixel match its color, then these
pixels are **DIFFERENT**. (In case of anti-aliasing, some of the
direct neighbors have to be blended up or down.) Otherwise, proceed
to next step.
1. If SSIM in some locality around the different pixels is more than
0.99, then consider this pixels to be **EQUAL**. Otherwise, mark them
as **DIFFERENT**. (Local SSIM for anti-aliased pixels turns out to be
very close to 1.0).
[CIE94]: https://en.wikipedia.org/wiki/Color_difference#CIE94
[just-noticeable difference]:
https://en.wikipedia.org/wiki/Just-noticeable_difference
This prevents shared workers from stalling upon restart.
We receive `Inspector.targetCrashed` and
`Inspector.targetReloadedAfterCrash` events that assume
`Runtime.runIfWaitingForDebugger` from any attached client. It is easier
and more stable to just detach from shared workers, because we do not
inspect them.
For service workers, we should actually issue
`Runtime.runIfWaitingForDebugger` in such cases, because we attach to
them.
Fixes#18932.
- Properly convert coordinates for iframes with non-zero borders.
- IFrames that have `transform` anywhere in the ancestors skip
`hitPoint`-based check because we cannot reliably translate the viewport
point into frame document's coordinates.
Fixes#18245.
Following the `getByText()` and other methods:
- By default, matching is substring and case-insensitive. Before, it was
only case-insensitive, but not substring.
- With new option `exact: true`, matching is full string and
case-sensitive.
- Matching always normalizes whitespace.
- Codegen generates `exact: false` by default.
- `internal:role` treats `[name="foo"i]` as non-exact match.
Various fixes:
- Updated `getByRole` docs to match the reality.
- Locator generator edge cases.
