[
  {
    "name": "24 ha at 200 L/ha and 2.5 L/ha with a 1000 L tank: four full tanks and 800 L",
    "args": [
      24,
      200,
      2.5,
      "litres",
      1000
    ],
    "expect": {
      "tankFills": 5,
      "fullTanks": 4,
      "fullTank": {
        "areaHectares": 5,
        "sprayLitres": 1000,
        "product": 12.5,
        "waterLitres": 987.5
      },
      "partialTank": {
        "areaHectares": 4,
        "sprayLitres": 800,
        "product": 10,
        "waterLitres": 790
      },
      "totalSprayLitres": 4800,
      "totalProduct": 60
    }
  },
  {
    "name": "a job of exactly two tanks has no part tank",
    "args": [
      10,
      100,
      1,
      "litres",
      500
    ],
    "expect": {
      "tankFills": 2,
      "fullTanks": 2,
      "fullTank": {
        "areaHectares": 5,
        "sprayLitres": 500,
        "product": 5,
        "waterLitres": 495
      },
      "partialTank": null,
      "totalSprayLitres": 1000,
      "totalProduct": 10
    }
  },
  {
    "name": "less than one tank: the full-tank recipe is still given",
    "args": [
      2,
      200,
      1.5,
      "litres",
      1000
    ],
    "expect": {
      "tankFills": 1,
      "fullTanks": 0,
      "fullTank": {
        "areaHectares": 5,
        "sprayLitres": 1000,
        "product": 7.5,
        "waterLitres": 992.5
      },
      "partialTank": {
        "areaHectares": 2,
        "sprayLitres": 400,
        "product": 3,
        "waterLitres": 397
      },
      "totalSprayLitres": 400,
      "totalProduct": 3
    }
  },
  {
    "name": "a solid product in kg does not displace water",
    "args": [
      12,
      150,
      0.25,
      "kilograms",
      600
    ],
    "expect": {
      "tankFills": 3,
      "fullTanks": 3,
      "fullTank": {
        "areaHectares": 4,
        "sprayLitres": 600,
        "product": 1,
        "waterLitres": 600
      },
      "partialTank": null,
      "totalSprayLitres": 1800,
      "totalProduct": 3
    }
  },
  {
    "name": "awkward numbers: the full and part tank products add up to the job's",
    "args": [
      7.3,
      120,
      0.67,
      "litres",
      800
    ],
    "expect": {
      "tankFills": 2,
      "fullTanks": 1,
      "fullTank": {
        "areaHectares": 6.6667,
        "sprayLitres": 800,
        "product": 4.467,
        "waterLitres": 795.533
      },
      "partialTank": {
        "areaHectares": 0.6333,
        "sprayLitres": 76,
        "product": 0.424,
        "waterLitres": 75.576
      },
      "totalSprayLitres": 876,
      "totalProduct": 4.891
    }
  },
  {
    "name": "129.2 ha at 250 L/ha is exactly 19 tanks of 1700 L, not 18 and a sliver",
    "args": [
      129.2,
      250,
      1,
      "litres",
      1700
    ],
    "expect": {
      "tankFills": 19,
      "fullTanks": 19,
      "fullTank": {
        "areaHectares": 6.8,
        "sprayLitres": 1700,
        "product": 6.8,
        "waterLitres": 1693.2
      },
      "partialTank": null,
      "totalSprayLitres": 32300,
      "totalProduct": 129.2
    }
  },
  {
    "name": "water only (no product)",
    "args": [
      5,
      100,
      0,
      "litres",
      300
    ],
    "expect": {
      "tankFills": 2,
      "fullTanks": 1,
      "fullTank": {
        "areaHectares": 3,
        "sprayLitres": 300,
        "product": 0,
        "waterLitres": 300
      },
      "partialTank": {
        "areaHectares": 2,
        "sprayLitres": 200,
        "product": 0,
        "waterLitres": 200
      },
      "totalSprayLitres": 500,
      "totalProduct": 0
    }
  },
  {
    "name": "the smallest area, one square metre",
    "args": [
      0.0001,
      200,
      1,
      "litres",
      1000
    ],
    "expect": {
      "tankFills": 1,
      "fullTanks": 0,
      "fullTank": {
        "areaHectares": 5,
        "sprayLitres": 1000,
        "product": 5,
        "waterLitres": 995
      },
      "partialTank": {
        "areaHectares": 0.0001,
        "sprayLitres": 0.02,
        "product": 0,
        "waterLitres": 0.02
      },
      "totalSprayLitres": 0.02,
      "totalProduct": 0
    }
  },
  {
    "name": "zero area is an error",
    "args": [
      0,
      200,
      1,
      "litres",
      1000
    ],
    "expectError": "areaHectares must be at least 0.0001 hectares"
  },
  {
    "name": "a negative dose is an error",
    "args": [
      10,
      200,
      -1,
      "litres",
      1000
    ],
    "expectError": "productDosePerHectare must be a finite number from 0 to 100"
  },
  {
    "name": "zero water volume is an error",
    "args": [
      10,
      0,
      1,
      "litres",
      1000
    ],
    "expectError": "waterVolumeLitresPerHectare must be at least 0.1 litres"
  },
  {
    "name": "zero tank is an error",
    "args": [
      10,
      200,
      1,
      "litres",
      0
    ],
    "expectError": "tankLitres must be at least 0.1 litres"
  },
  {
    "name": "a liquid dose as large as the water volume is an error",
    "args": [
      10,
      50,
      50,
      "litres",
      1000
    ],
    "expectError": "productDosePerHectare must be less than waterVolumeLitresPerHectare for a liquid product"
  },
  {
    "name": "an unknown dose unit is an error",
    "args": [
      10,
      200,
      1,
      "gallons",
      1000
    ],
    "expectError": "unknown doseUnit \"gallons\""
  }
]