✨Feature: add character creation logic and tests

- Implement character creation functions to handle adventurer setup.
- Add validation for adventurer name and selection of starting items.
- Introduce new items in sample content pack: Flint and Steel, Pouch, Wax Sealing Kit, and Backpack.
- Create tests for character creation functionality to ensure valid options and error handling.

✨Feature: implement dice rolling mechanics and tests

- Add functions for rolling various dice types (d3, d6, 2d6, d66) with validation.
- Implement modifier application with clamping for roll results.
- Create tests to verify correct behavior of dice rolling functions.

✨Feature: add table lookup functionality and tests

- Implement table lookup and resolution logic for defined tables.
- Support for modified ranges and fallback to nearest entries.
- Create tests to ensure correct table entry resolution based on roll results.

src/rules/character.test.ts

@@ -0,0 +1,50 @@
+import { describe, expect, it } from "vitest";
+
+import { sampleContentPack } from "@/data/sampleContentPack";
+
+import { createStartingAdventurer, getCharacterCreationOptions } from "./character";
+
+describe("character creation", () => {
+  it("exposes legal starting options from the content pack", () => {
+    const options = getCharacterCreationOptions(sampleContentPack);
+
+    expect(options.weapons).toHaveLength(1);
+    expect(options.armour).toHaveLength(1);
+    expect(options.scrolls).toHaveLength(1);
+  });
+
+  it("builds a valid starting adventurer from legal choices", () => {
+    const adventurer = createStartingAdventurer(sampleContentPack, {
+      name: "Mira",
+      weaponId: "weapon.short-sword",
+      armourId: "armour.leather-vest",
+      scrollId: "scroll.lesser-heal",
+    });
+
+    expect(adventurer.name).toBe("Mira");
+    expect(adventurer.level).toBe(1);
+    expect(adventurer.stats.shift).toBe(2);
+    expect(adventurer.manoeuvreIds).toEqual([
+      "manoeuvre.exact-strike",
+      "manoeuvre.guard-break",
+    ]);
+    expect(adventurer.inventory.rationCount).toBe(3);
+    expect(adventurer.inventory.carried).toEqual(
+      expect.arrayContaining([
+        expect.objectContaining({ definitionId: "potion.healing", quantity: 1 }),
+        expect.objectContaining({ definitionId: "scroll.lesser-heal", quantity: 1 }),
+      ]),
+    );
+  });
+
+  it("rejects an empty adventurer name", () => {
+    expect(() =>
+      createStartingAdventurer(sampleContentPack, {
+        name: "   ",
+        weaponId: "weapon.short-sword",
+        armourId: "armour.leather-vest",
+        scrollId: "scroll.lesser-heal",
+      }),
+    ).toThrow("Adventurer name is required.");
+  });
+});

src/rules/character.ts

@@ -0,0 +1,128 @@
+import type { ContentPack } from "@/types/content";
+import type { AdventurerState, InventoryEntry } from "@/types/state";
+
+export type CharacterCreationChoiceSet = {
+  name: string;
+  weaponId: string;
+  armourId: string;
+  scrollId: string;
+};
+
+const DEFAULT_STARTING_ITEM_IDS = [
+  "item.flint-and-steel",
+  "item.lantern",
+  "item.ration",
+  "item.pouch",
+  "item.wax-sealing-kit",
+  "item.backpack",
+];
+
+function requireDefinition<T extends { id: string }>(
+  entries: T[],
+  id: string,
+  label: string,
+) {
+  const entry = entries.find((candidate) => candidate.id === id);
+
+  if (!entry) {
+    throw new Error(`Unknown ${label} id: ${id}`);
+  }
+
+  return entry;
+}
+
+function makeInventoryEntry(definitionId: string, quantity = 1): InventoryEntry {
+  return {
+    definitionId,
+    quantity,
+  };
+}
+
+export function getCharacterCreationOptions(content: ContentPack) {
+  return {
+    weapons: content.weapons.filter((weapon) => weapon.startingOption),
+    armour: content.armour.filter((armour) => armour.startingOption),
+    scrolls: content.scrolls.filter((scroll) => scroll.startingOption),
+  };
+}
+
+export function createStartingAdventurer(
+  content: ContentPack,
+  choices: CharacterCreationChoiceSet,
+): AdventurerState {
+  const trimmedName = choices.name.trim();
+
+  if (trimmedName.length === 0) {
+    throw new Error("Adventurer name is required.");
+  }
+
+  const selectedWeapon = requireDefinition(content.weapons, choices.weaponId, "weapon");
+  const selectedArmour = requireDefinition(content.armour, choices.armourId, "armour");
+  const selectedScroll = requireDefinition(content.scrolls, choices.scrollId, "scroll");
+
+  if (!selectedWeapon.startingOption) {
+    throw new Error(`Weapon ${selectedWeapon.id} is not a legal starting option.`);
+  }
+
+  if (!selectedArmour.startingOption) {
+    throw new Error(`Armour ${selectedArmour.id} is not a legal starting option.`);
+  }
+
+  if (!selectedScroll.startingOption) {
+    throw new Error(`Scroll ${selectedScroll.id} is not a legal starting option.`);
+  }
+
+  const allowedManoeuvreIds = selectedWeapon.allowedManoeuvreIds;
+
+  if (allowedManoeuvreIds.length === 0) {
+    throw new Error(`Weapon ${selectedWeapon.id} does not define starting manoeuvres.`);
+  }
+
+  DEFAULT_STARTING_ITEM_IDS.forEach((itemId) => requireDefinition(content.items, itemId, "item"));
+  requireDefinition(content.potions, "potion.healing", "potion");
+
+  return {
+    id: "adventurer.new",
+    name: trimmedName,
+    level: 1,
+    xp: 0,
+    hp: {
+      current: 10,
+      max: 10,
+      base: 10,
+    },
+    stats: {
+      shift: 2,
+      discipline: 1,
+      precision: 0,
+    },
+    weaponId: selectedWeapon.id,
+    manoeuvreIds: allowedManoeuvreIds,
+    armourId: selectedArmour.id,
+    favour: {},
+    statuses: [],
+    inventory: {
+      carried: [
+        makeInventoryEntry("item.flint-and-steel"),
+        makeInventoryEntry("item.lantern"),
+        makeInventoryEntry("item.ration", 3),
+        makeInventoryEntry("item.pouch"),
+        makeInventoryEntry("item.wax-sealing-kit"),
+        makeInventoryEntry("item.backpack"),
+        makeInventoryEntry(selectedScroll.id),
+        makeInventoryEntry("potion.healing"),
+      ],
+      equipped: [
+        makeInventoryEntry(selectedWeapon.id),
+        makeInventoryEntry(selectedArmour.id),
+      ],
+      stored: [],
+      currency: {
+        gold: 0,
+      },
+      rationCount: 3,
+      lightSources: [makeInventoryEntry("item.lantern")],
+    },
+    progressionFlags: [],
+  };
+}

src/rules/dice.test.ts

@@ -0,0 +1,46 @@
+import { describe, expect, it } from "vitest";
+
+import { applyRollModifier, roll2D6, rollD3, rollD66, rollDice } from "./dice";
+
+function createSequenceRoller(values: number[]) {
+  let index = 0;
+
+  return () => {
+    const next = values[index];
+    index += 1;
+    return next;
+  };
+}
+
+describe("dice rules", () => {
+  it("maps d3 rolls from a d6 source", () => {
+    const result = rollD3(createSequenceRoller([5]));
+
+    expect(result.rolls).toEqual([5]);
+    expect(result.total).toBe(3);
+    expect(result.modifiedTotal).toBe(3);
+  });
+
+  it("preserves primary and secondary dice for d66", () => {
+    const result = rollD66(createSequenceRoller([4, 2]));
+
+    expect(result.primary).toBe(4);
+    expect(result.secondary).toBe(2);
+    expect(result.total).toBe(42);
+  });
+
+  it("applies modifiers with clamping when limits are provided", () => {
+    const roll = roll2D6(createSequenceRoller([6, 6]));
+    const modified = applyRollModifier(roll, 3, { min: 2, max: 12 });
+
+    expect(modified.modifiedTotal).toBe(12);
+    expect(modified.clamped).toBe(true);
+  });
+
+  it("routes dice kinds through the shared roller", () => {
+    const result = rollDice("d6", createSequenceRoller([2]));
+
+    expect(result.total).toBe(2);
+    expect(result.diceKind).toBe("d6");
+  });
+});

src/rules/dice.ts

@@ -0,0 +1,113 @@
+import type { DiceKind, RollResult } from "@/types/rules";
+
+export type DiceRoller = (sides: number) => number;
+
+const defaultDiceRoller: DiceRoller = (sides) =>
+  Math.floor(Math.random() * sides) + 1;
+
+function assertRollInRange(value: number, sides: number) {
+  if (!Number.isInteger(value) || value < 1 || value > sides) {
+    throw new Error(`Dice roller returned invalid value ${value} for d${sides}.`);
+  }
+}
+
+function clampTotal(total: number, min: number, max: number) {
+  return Math.max(min, Math.min(max, total));
+}
+
+export function rollD3(roller: DiceRoller = defaultDiceRoller): RollResult {
+  const value = roller(6);
+  assertRollInRange(value, 6);
+  const total = Math.ceil(value / 2);
+
+  return {
+    diceKind: "d3",
+    rolls: [value],
+    total,
+    modifiedTotal: total,
+  };
+}
+
+export function rollD6(roller: DiceRoller = defaultDiceRoller): RollResult {
+  const value = roller(6);
+  assertRollInRange(value, 6);
+
+  return {
+    diceKind: "d6",
+    rolls: [value],
+    total: value,
+    modifiedTotal: value,
+  };
+}
+
+export function roll2D6(roller: DiceRoller = defaultDiceRoller): RollResult {
+  const first = roller(6);
+  const second = roller(6);
+  assertRollInRange(first, 6);
+  assertRollInRange(second, 6);
+  const total = first + second;
+
+  return {
+    diceKind: "2d6",
+    rolls: [first, second],
+    primary: first,
+    secondary: second,
+    total,
+    modifiedTotal: total,
+  };
+}
+
+export function rollD66(roller: DiceRoller = defaultDiceRoller): RollResult {
+  const primary = roller(6);
+  const secondary = roller(6);
+  assertRollInRange(primary, 6);
+  assertRollInRange(secondary, 6);
+  const total = primary * 10 + secondary;
+
+  return {
+    diceKind: "d66",
+    rolls: [primary, secondary],
+    primary,
+    secondary,
+    total,
+    modifiedTotal: total,
+  };
+}
+
+export function applyRollModifier(
+  roll: RollResult,
+  modifier = 0,
+  limits?: { min: number; max: number },
+): RollResult {
+  if (roll.total === undefined) {
+    throw new Error("Cannot apply a modifier to a roll without a total.");
+  }
+
+  const nextTotal = roll.total + modifier;
+  const boundedTotal = limits
+    ? clampTotal(nextTotal, limits.min, limits.max)
+    : nextTotal;
+
+  return {
+    ...roll,
+    modifier,
+    modifiedTotal: boundedTotal,
+    clamped: limits ? boundedTotal !== nextTotal : false,
+  };
+}
+
+export function rollDice(
+  diceKind: DiceKind,
+  roller: DiceRoller = defaultDiceRoller,
+): RollResult {
+  switch (diceKind) {
+    case "d3":
+      return rollD3(roller);
+    case "d6":
+      return rollD6(roller);
+    case "2d6":
+      return roll2D6(roller);
+    case "d66":
+      return rollD66(roller);
+  }
+}

src/rules/tables.test.ts

@@ -0,0 +1,62 @@
+import { describe, expect, it } from "vitest";
+
+import type { TableDefinition } from "@/types/content";
+
+import { lookupTable, resolveTableEntry } from "./tables";
+
+function createSequenceRoller(values: number[]) {
+  let index = 0;
+
+  return () => {
+    const next = values[index];
+    index += 1;
+    return next;
+  };
+}
+
+const d6Table: TableDefinition = {
+  id: "table.sample",
+  code: "SAMPLE1",
+  name: "Sample Table",
+  category: "generic",
+  page: 1,
+  diceKind: "d6",
+  usesModifiedRangesRule: true,
+  entries: [
+    { key: "1", exact: 1, label: "One" },
+    { key: "2-5", min: 2, max: 5, label: "Two to Five" },
+    { key: "6", exact: 6, label: "Six" },
+  ],
+  mvp: true,
+};
+
+describe("table lookup rules", () => {
+  it("finds a matching exact entry", () => {
+    const result = lookupTable(d6Table, { roller: createSequenceRoller([6]) });
+
+    expect(result.entry.label).toBe("Six");
+    expect(result.roll.total).toBe(6);
+  });
+
+  it("clamps modified results when the table uses modified ranges", () => {
+    const result = lookupTable(d6Table, {
+      roller: createSequenceRoller([6]),
+      modifier: 3,
+    });
+
+    expect(result.entry.label).toBe("Six");
+    expect(result.roll.modifiedTotal).toBe(6);
+    expect(result.roll.clamped).toBe(true);
+  });
+
+  it("falls back to the nearest numeric entry for direct resolution", () => {
+    const result = resolveTableEntry(d6Table, {
+      diceKind: "d6",
+      rolls: [0],
+      total: 4,
+      modifiedTotal: 7,
+    });
+
+    expect(result.entry.label).toBe("Six");
+  });
+});

src/rules/tables.ts

@@ -0,0 +1,110 @@
+import type { TableDefinition, TableEntry } from "@/types/content";
+import type { RollResult } from "@/types/rules";
+
+import { applyRollModifier, rollDice, type DiceRoller } from "./dice";
+
+export type TableLookupResult = {
+  tableId: string;
+  entryKey: string;
+  roll: RollResult;
+  entry: TableEntry;
+};
+
+function getNumericEntryValue(entry: TableEntry) {
+  if (entry.d66 !== undefined) {
+    return entry.d66;
+  }
+
+  if (entry.exact !== undefined) {
+    return entry.exact;
+  }
+
+  return undefined;
+}
+
+function getEntryBounds(entries: TableEntry[]) {
+  const values = entries
+    .flatMap((entry) => {
+      if (entry.min !== undefined && entry.max !== undefined) {
+        return [entry.min, entry.max];
+      }
+
+      const exactValue = getNumericEntryValue(entry);
+      return exactValue !== undefined ? [exactValue] : [];
+    })
+    .sort((a, b) => a - b);
+
+  if (values.length === 0) {
+    throw new Error("Cannot compute table bounds for an empty numeric table.");
+  }
+
+  return { min: values[0], max: values[values.length - 1] };
+}
+
+function matchesEntry(entry: TableEntry, lookupValue: number) {
+  if (entry.min !== undefined && entry.max !== undefined) {
+    return lookupValue >= entry.min && lookupValue <= entry.max;
+  }
+
+  const exactValue = getNumericEntryValue(entry);
+  return exactValue === lookupValue;
+}
+
+function findNearestEntry(entries: TableEntry[], lookupValue: number) {
+  return entries
+    .map((entry) => ({ entry, value: getNumericEntryValue(entry) }))
+    .filter((candidate): candidate is { entry: TableEntry; value: number } => {
+      return candidate.value !== undefined;
+    })
+    .sort((left, right) => {
+      const distanceDelta =
+        Math.abs(left.value - lookupValue) - Math.abs(right.value - lookupValue);
+
+      return distanceDelta !== 0 ? distanceDelta : left.value - right.value;
+    })[0]?.entry;
+}
+
+export function resolveTableEntry(
+  table: TableDefinition,
+  roll: RollResult,
+): TableLookupResult {
+  const lookupValue = roll.modifiedTotal ?? roll.total;
+
+  if (lookupValue === undefined) {
+    throw new Error(`Cannot resolve table ${table.code} without a roll total.`);
+  }
+
+  const matchingEntry = table.entries.find((entry) => matchesEntry(entry, lookupValue));
+  const fallbackEntry = matchingEntry ?? findNearestEntry(table.entries, lookupValue);
+
+  if (!fallbackEntry) {
+    throw new Error(`No table entry found for ${table.code} with value ${lookupValue}.`);
+  }
+
+  return {
+    tableId: table.id,
+    entryKey: fallbackEntry.key,
+    roll,
+    entry: fallbackEntry,
+  };
+}
+
+export function lookupTable(
+  table: TableDefinition,
+  options?: {
+    modifier?: number;
+    roller?: DiceRoller;
+  },
+): TableLookupResult {
+  const rawRoll = rollDice(table.diceKind, options?.roller);
+  const roll =
+    options?.modifier !== undefined
+      ? applyRollModifier(
+          rawRoll,
+          options.modifier,
+          table.usesModifiedRangesRule ? getEntryBounds(table.entries) : undefined,
+        )
+      : rawRoll;
+
+  return resolveTableEntry(table, roll);
+}