feat: Add options.ignoreMask of pixels to skip

[Venefilyn]

New check where if a value from ignoreMask is greater than 0 it will
be ignored from the check. The ignore mask itself needs to be exact
width and height of the images provided.

One could write an array manually or provide a PNG image by use of a
custom helper function beforehand, further making it more extensible.
Any value greater than 0 will be skipped.

Tests have been updated to include one test with a normal diff check
with an ignore mask that covers half the screen, and another diff check
where nothing should differ as all the changes are within the ignore mask but makes sure the fast path is executed.

Fixes: #163
Closes: #153

[ox-security]

OX Security reviewed this pull request — nothing to fix.

✔ No issues found

Branch feat/ignore-areas → main

View scan in OX Security →

[mourner]

Looks like a bunch of tests are failing — let's make sure the CI is green first

[Venefilyn]

Looks like a bunch of tests are failing — let's make sure the CI is green first

Woops, was refactoring and made a mistake in the if-statement. Should've been

-        if (!inIgnoreMask && a32[i] === b32[i]) {
+        if (!inIgnoreMask && a32[i] !== b32[i]) {

[mourner]

Also, it seems like adding two sets of fixtures for this is a bit redundant — we could get away with just one (one darker, and a diff that shows only the non-masked portion was highlighted).

[Venefilyn]

Also, it seems like adding two sets of fixtures for this is a bit redundant — we could get away with just one (one darker, and a diff that shows only the non-masked portion was highlighted).

Would you say 9a and 9b is enough then? I added fixture 10 to ensure check the fast check works with it

[mourner]

Ah, I guess we could leave those then. So, a few nits left and I'll land this before v8 release.

[Venefilyn]

Alrighty, updated based on last review. Updated the fast check as I had an incorrect statement there so it would never mark identical if it was inside an ignore change.

Before we go ahead with merging this, do we agree on options.ignoreMask or should we pick a different synonym? I'm fine with ignoreMask but unsure what users think :D

[mourner]

Great, thanks for being patient and getting this over the finish line! ignoreMask sounds good to me. I'll do some polishing and release v8 in a few days.