{
  "format": 1,
  "function": "resolve_range",
  "cases": [
    {
      "name": "this_month",
      "input": {
        "preset": "this_month",
        "today": "2026-10-17",
        "earliest_expense": "2024-03-05",
        "custom_start": null,
        "custom_end": null
      },
      "expected": {
        "ok": {
          "start": "2026-10-01",
          "end_inclusive": "2026-10-17"
        }
      }
    },
    {
      "name": "last_3_months: the current month and the two before",
      "input": {
        "preset": "last_3_months",
        "today": "2026-10-17",
        "earliest_expense": "2024-03-05",
        "custom_start": null,
        "custom_end": null
      },
      "expected": {
        "ok": {
          "start": "2026-08-01",
          "end_inclusive": "2026-10-17"
        }
      }
    },
    {
      "name": "last_6_months",
      "input": {
        "preset": "last_6_months",
        "today": "2026-10-17",
        "earliest_expense": "2024-03-05",
        "custom_start": null,
        "custom_end": null
      },
      "expected": {
        "ok": {
          "start": "2026-05-01",
          "end_inclusive": "2026-10-17"
        }
      }
    },
    {
      "name": "last_12_months: crosses into the previous year",
      "input": {
        "preset": "last_12_months",
        "today": "2026-10-17",
        "earliest_expense": "2024-03-05",
        "custom_start": null,
        "custom_end": null
      },
      "expected": {
        "ok": {
          "start": "2025-11-01",
          "end_inclusive": "2026-10-17"
        }
      }
    },
    {
      "name": "this_year",
      "input": {
        "preset": "this_year",
        "today": "2026-10-17",
        "earliest_expense": "2024-03-05",
        "custom_start": null,
        "custom_end": null
      },
      "expected": {
        "ok": {
          "start": "2026-01-01",
          "end_inclusive": "2026-10-17"
        }
      }
    },
    {
      "name": "all_time with an earliest expense",
      "input": {
        "preset": "all_time",
        "today": "2026-10-17",
        "earliest_expense": "2024-03-05",
        "custom_start": null,
        "custom_end": null
      },
      "expected": {
        "ok": {
          "start": "2024-03-05",
          "end_inclusive": "2026-10-17"
        }
      }
    },
    {
      "name": "all_time without expenses: today to today",
      "input": {
        "preset": "all_time",
        "today": "2026-10-17",
        "earliest_expense": null,
        "custom_start": null,
        "custom_end": null
      },
      "expected": {
        "ok": {
          "start": "2026-10-17",
          "end_inclusive": "2026-10-17"
        }
      }
    },
    {
      "name": "custom in order, future dates allowed",
      "input": {
        "preset": "custom",
        "today": "2026-10-17",
        "earliest_expense": null,
        "custom_start": "2026-11-01",
        "custom_end": "2026-12-31"
      },
      "expected": {
        "ok": {
          "start": "2026-11-01",
          "end_inclusive": "2026-12-31"
        }
      }
    },
    {
      "name": "custom swapped when start is after end",
      "input": {
        "preset": "custom",
        "today": "2026-10-17",
        "earliest_expense": null,
        "custom_start": "2026-12-31",
        "custom_end": "2026-11-01"
      },
      "expected": {
        "ok": {
          "start": "2026-11-01",
          "end_inclusive": "2026-12-31"
        }
      }
    },
    {
      "name": "custom single day",
      "input": {
        "preset": "custom",
        "today": "2026-10-17",
        "earliest_expense": null,
        "custom_start": "2026-02-28",
        "custom_end": "2026-02-28"
      },
      "expected": {
        "ok": {
          "start": "2026-02-28",
          "end_inclusive": "2026-02-28"
        }
      }
    },
    {
      "name": "last_3_months in January crosses the year",
      "input": {
        "preset": "last_3_months",
        "today": "2027-01-01",
        "earliest_expense": null,
        "custom_start": null,
        "custom_end": null
      },
      "expected": {
        "ok": {
          "start": "2026-11-01",
          "end_inclusive": "2027-01-01"
        }
      }
    },
    {
      "name": "last_12_months on 31 March: first of April the year before",
      "input": {
        "preset": "last_12_months",
        "today": "2027-03-31",
        "earliest_expense": null,
        "custom_start": null,
        "custom_end": null
      },
      "expected": {
        "ok": {
          "start": "2026-04-01",
          "end_inclusive": "2027-03-31"
        }
      }
    },
    {
      "name": "this_month on the first day of the month",
      "input": {
        "preset": "this_month",
        "today": "2026-11-01",
        "earliest_expense": null,
        "custom_start": null,
        "custom_end": null
      },
      "expected": {
        "ok": {
          "start": "2026-11-01",
          "end_inclusive": "2026-11-01"
        }
      }
    }
  ]
}