This test verifies the names, positions and sizes of the highlight rectangles overlayed on CSS Grid areas.

grid-with-areas{
  "paths": [
    {
      "path": [
        "M",
        0,
        0,
        "L",
        401,
        0,
        "L",
        401,
        601,
        "L",
        0,
        601,
        "Z"
      ],
      "fillColor": "rgba(255, 0, 0, 0)",
      "outlineColor": "rgba(128, 0, 0, 0)",
      "name": "content"
    },
    {
      "path": [
        "M",
        0,
        0,
        "L",
        401,
        0,
        "L",
        401,
        601,
        "L",
        0,
        601,
        "Z"
      ],
      "fillColor": "rgba(0, 255, 0, 0)",
      "name": "padding"
    },
    {
      "path": [
        "M",
        0,
        0,
        "L",
        401,
        0,
        "L",
        401,
        601,
        "L",
        0,
        601,
        "Z"
      ],
      "fillColor": "rgba(0, 0, 255, 0)",
      "name": "border"
    },
    {
      "path": [
        "M",
        0,
        0,
        "L",
        401,
        0,
        "L",
        401,
        601,
        "L",
        0,
        601,
        "Z"
      ],
      "fillColor": "rgba(255, 255, 255, 0)",
      "name": "margin"
    }
  ],
  "showRulers": true,
  "showExtensionLines": true,
  "showAccessibilityInfo": true,
  "colorFormat": "hex",
  "elementInfo": {
    "tagName": "div",
    "idValue": "grid-with-areas",
    "nodeWidth": "401",
    "nodeHeight": "601",
    "isKeyboardFocusable": false,
    "accessibleName": "",
    "accessibleRole": "generic",
    "layoutObjectName": "LayoutGrid",
    "showAccessibilityInfo": true
  },
  "gridInfo": [
    {
      "rotationAngle": 0,
      "writingMode": "horizontal-tb",
      "columnTrackSizes": [
        {
          "x": 97.75,
          "y": 0,
          "computedSize": 195.5,
          "authoredSize": "1fr"
        },
        {
          "x": 303.25,
          "y": 0,
          "computedSize": 195.5,
          "authoredSize": "1fr"
        }
      ],
      "rowTrackSizes": [
        {
          "x": 0,
          "y": 147.75,
          "computedSize": 295.5,
          "authoredSize": "1fr"
        },
        {
          "x": 0,
          "y": 453.25,
          "computedSize": 295.5,
          "authoredSize": "1fr"
        }
      ],
      "rows": [
        "M",
        0,
        0,
        "L",
        401,
        0,
        "M",
        401,
        295.5,
        "L",
        0,
        295.5,
        "M",
        0,
        305.5,
        "L",
        401,
        305.5,
        "M",
        401,
        601,
        "L",
        0,
        601
      ],
      "rowGaps": [
        "M",
        0,
        295.5,
        "L",
        401,
        295.5,
        "L",
        401,
        305.5,
        "L",
        0,
        305.5,
        "Z"
      ],
      "columns": [
        "M",
        0,
        0,
        "L",
        0,
        601,
        "M",
        195.5,
        601,
        "L",
        195.5,
        0,
        "M",
        205.5,
        0,
        "L",
        205.5,
        601,
        "M",
        401,
        601,
        "L",
        401,
        0
      ],
      "columnGaps": [
        "M",
        195.5,
        0,
        "L",
        205.5,
        0,
        "L",
        205.5,
        601,
        "L",
        195.5,
        601,
        "Z"
      ],
      "positiveRowLineNumberPositions": [
        {
          "x": 0,
          "y": 0
        },
        {
          "x": 0,
          "y": 300.5
        },
        {
          "x": 0,
          "y": 601
        }
      ],
      "positiveColumnLineNumberPositions": [
        {
          "x": 0,
          "y": 0
        },
        {
          "x": 200.5,
          "y": 0
        },
        {
          "x": 401,
          "y": 0
        }
      ],
      "negativeRowLineNumberPositions": [
        {
          "x": 401,
          "y": 0
        },
        {
          "x": 401,
          "y": 300.5
        },
        {
          "x": 401,
          "y": 601
        }
      ],
      "negativeColumnLineNumberPositions": [
        {
          "x": 0,
          "y": 601
        },
        {
          "x": 200.5,
          "y": 601
        },
        {
          "x": 401,
          "y": 601
        }
      ],
      "areaNames": {
        "header": [
          "M",
          0,
          0,
          "L",
          401,
          0,
          "L",
          401,
          295.5,
          "L",
          0,
          295.5,
          "Z"
        ],
        "sidebar": [
          "M",
          0,
          305.5,
          "L",
          195.5,
          305.5,
          "L",
          195.5,
          601,
          "L",
          0,
          601,
          "Z"
        ],
        "main": [
          "M",
          205.5,
          305.5,
          "L",
          401,
          305.5,
          "L",
          401,
          601,
          "L",
          205.5,
          601,
          "Z"
        ]
      },
      "rowLineNameOffsets": [],
      "columnLineNameOffsets": [],
      "gridBorder": [
        "M",
        0,
        0,
        "L",
        401,
        0,
        "L",
        401,
        601,
        "L",
        0,
        601,
        "Z"
      ],
      "gridHighlightConfig": {
        "gridBorderDash": false,
        "rowLineDash": true,
        "columnLineDash": true,
        "showGridExtensionLines": true,
        "showPositiveLineNumbers": true,
        "showNegativeLineNumbers": true,
        "showAreaNames": true,
        "showLineNames": true,
        "gridBorderColor": "rgba(255, 0, 0, 0)",
        "rowLineColor": "rgba(128, 0, 0, 0)",
        "columnLineColor": "rgba(128, 0, 0, 0)",
        "rowGapColor": "rgba(0, 255, 0, 0)",
        "columnGapColor": "rgba(0, 0, 255, 0)",
        "rowHatchColor": "rgba(255, 255, 255, 0)",
        "columnHatchColor": "rgba(128, 128, 128, 0)",
        "areaBorderColor": "rgba(255, 0, 0, 0)",
        "gridBackgroundColor": "rgba(255, 0, 0, 0)"
      },
      "isPrimaryGrid": true
    }
  ]
}