fix: pass matcher threshold to core as saveAboveTolerance

[wswebcreation]

Summary

Fixes #1111 - When using visual matchers like toMatchScreenSnapshot('tag', 0.9) with alwaysSaveActualImage: false, the actual image was still being saved even when the comparison passed within the threshold.

Root Cause

There were two disconnected threshold systems:

1. Core (images.ts): Used saveAboveTolerance (defaulting to 0) to decide whether to save images
2. Matcher (matcher.ts): Used the user-provided expected threshold to determine pass/fail

When a user set a threshold like 0.9, the core didn't know about it - it still used the default 0, causing images to be saved for any non-zero mismatch.

Solution

The matcher now passes the expected threshold to the core as saveAboveTolerance in the parseMatcherParams function:

• Numeric thresholds are passed directly
• When no threshold is provided, defaults to 0 (matching existing behavior)
• User-provided saveAboveTolerance is respected (not overridden)
• Asymmetric matchers (e.g., expect.any(Number)) cannot be converted to numeric, so default behavior is used

Example

Before (broken):

Component	Threshold	Decision
Core	saveAboveTolerance: 0 (default)	0.05 > 0 → save image
Matcher	expected: 0.9	0.05 <= 0.9 → test passes

After (fixed):

Component	Threshold	Decision
Core	saveAboveTolerance: 0.9 (from matcher)	0.05 > 0.9 = false → don't save
Matcher	expected: 0.9	0.05 <= 0.9 → test passes

Test plan

• Added unit tests for threshold passthrough to all matcher functions
• Added tests for default behavior (no threshold → 0)
• Added tests for user-provided saveAboveTolerance (no override)
• Added tests for asymmetric matchers
• All 827 existing tests pass

[changeset-bot]

🦋 Changeset detected

Latest commit: 95b3b79

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@wdio/visual-service	Patch

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