GitHub Actions - Add custom severity mapping inside problem matchers please

[ale5000-git]

Please add custom severity mapping inside problem matchers.

I propose this syntax:

{
  "problemMatcher": [
    {
      "owner": "test-matcher",
      "severity": "warning",
      "pattern": [
        {
          "regexp": "^(\\033\\[31|\\033\\[32|warn|style)(.+)$",
          "severity": 1,
          "message": 2
        }
      ],
      "severityMatcher": [
        {
          "regexp": "^styles?$",
          "severity": "notice",
        },
        {
          "regexp": "^warn$",
          "severity": "warning",
        },
        {
          "regexp": "^\\033\\[31$",
          "severity": "error",
        },
        {
          "regexp": "^\\033\\[32$",
          "severity": "notice",
        }
      ]
    }
  ]
}

[jsoref]

So, this isn't strictly necessary as you can address it with 3 problem matchers:

{
  "problemMatcher": [
    {
      "owner": "test-matcher-notice",
      "severity": "notice",
      "pattern": [
        {
          "regexp": "^(?:\\033\\[32|styles?)(.+)$",
          "message": 1
        }
      ]
    },
    {
      "owner": "test-matcher-warning",
      "severity": "warning",
      "pattern": [
        {
          "regexp": "^warn(.+)$",
          "message": 1
        }
      ]
    },
    {
      "owner": "test-matcher-error",
      "severity": "error",
      "pattern": [
        {
          "regexp": "^\\033\\[31(.+)$",
          "message": 1
        }
      ]
    }
  ]
}

It's moderately annoying, but mostly because the documentation is so poor that it's really hard to figure out that you can do this.

I'm mostly commenting here so that my future self will find this comment and remember how to do it.