fix: remove yaml warnings

Due to the fact that newer versions of yaml library (1.7.0+)
produce warning when trying to print nested objects in `set`
and at the same time tap-mocha-reporter doesn't support yaml
output that fixes this warning (mapAsMap: true) we have to just
silence them like this.
This would still result in "empty" diff on some reporters but
at least we will not get warnings that clutter whole report.

Refs: #265

CHANGELOG.md

@@ -12,6 +12,8 @@ and this project adheres to
 
 - bug where `test.endAfterSubtests()` would cause an error if the test was
   finished before `endAfterSubtests` got a chance to process its checks.
+- remove warnings from `yaml` library that are not actionable right now
+  [see issue](https://github.com/metarhia/metatests/issues/265).
 
 ## [0.8.1][] - 2022-03-06
 

lib/report.js

@@ -4,6 +4,15 @@ const { iter, capitalize } = require('@metarhia/common');
 const yaml = require('yaml');
 const yamlCustomTags = require('tap-yaml/lib/types/index.js');
 
+// TODO: replace tap-yaml and tap-mocha-reporter - due to the fact that
+//  newer versions of yaml library (1.7.0+) produce warning when trying to print
+//  nested objects in `set` and at the same time tap-mocha-reporter doesn't
+//  support yaml output that fixes this warning (mapAsMap: true) we have to just
+//  silence them like this.
+//  This would still result in "empty" diff on some reporters but at least we
+//  will not get warnings that clutter whole report.
+process.env.YAML_SILENCE_WARNINGS = 'true';
+
 const { inspect, packageRegex, isDate, isRegExp, isError } = require('./utils');
 
 let TSR = null;