fix(parser): fix empty array and nested bracket parsing

Improve the `ValueParser` to correctly disambiguate between empty
arrays `[]` and the start of nested structures. This ensures that
the parser can distinguish between an array containing a single
element that starts with a bracket and an actual empty array.

Update tests to reflect that parsed tuples are returned as arrays
rather than objects.

src/csv-loader/fixtures/encounter.csv

@@ -0,0 +1,7 @@
+# type EncounterType = 'minion'|'elite'|'event'|'shop'|'camp'|'curio'
+# type EnemyList = [name: string; hp: int; effects: [effect: string;stacks: int][]][]
+
+id,type,name,description,enemies,dialogue
+string,EncounterType,string,string,EnemyList,string
+cactus_pair,minion,仙人掌怪,概念：防+强化。【尖刺X】：对攻击者造成X点伤害。,[仙人掌怪;12;[]];[仙人掌怪;12;[]],
+snake_pair,minion,蛇,概念：攻+强化。给玩家塞入蛇毒牌（1费：打出时移除此牌。弃掉时受到3点伤害）。,[蛇;10;[[poison;2];[quick;1]]],

src/csv-loader/tests/parseCsv-combinators.test.ts

@@ -1,7 +1,7 @@
 import { describe, it, expect } from "vitest";
 import { parseCsv } from "../loader";
 import * as path from "path";
-import { fixturesDir } from "../test-utils";
+import { fixturesDir, readFixture } from "../test-utils";
 
 describe("parseCsv - references in combinatory schemas", () => {
   it("should resolve reference inside a tuple", () => {
@@ -161,4 +161,50 @@ describe("parseCsv - references in combinatory schemas", () => {
     });
     expect(details[1]).toBe(5);
   });
+
+  it("should parse encounter fixture with custom type aliases and nested tuples/arrays", () => {
+    const encounterCsv = readFixture("encounter.csv");
+
+    const result = parseCsv(encounterCsv, {
+      emitTypes: false,
+      currentFilePath: path.join(fixturesDir, "encounter.csv"),
+    });
+
+    expect(result.data).toHaveLength(2);
+
+    // First row: cactus_pair
+    expect(result.data[0]).toMatchObject({
+      id: "cactus_pair",
+      type: "minion",
+      name: "仙人掌怪",
+      description: "概念：防+强化。【尖刺X】：对攻击者造成X点伤害。",
+      dialogue: "",
+    });
+
+    const cactusEnemies = result.data[0].enemies as unknown[];
+    expect(cactusEnemies).toHaveLength(2);
+    expect(cactusEnemies[0]).toEqual(["仙人掌怪", 12, []]);
+    expect(cactusEnemies[1]).toEqual(["仙人掌怪", 12, []]);
+
+    // Second row: snake_pair
+    expect(result.data[1]).toMatchObject({
+      id: "snake_pair",
+      type: "minion",
+      name: "蛇",
+      description:
+        "概念：攻+强化。给玩家塞入蛇毒牌（1费：打出时移除此牌。弃掉时受到3点伤害）。",
+      dialogue: "",
+    });
+
+    const snakeEnemies = result.data[1].enemies as unknown[];
+    expect(snakeEnemies).toHaveLength(1);
+    expect(snakeEnemies[0]).toEqual([
+      "蛇",
+      10,
+      [
+        ["poison", 2],
+        ["quick", 1],
+      ],
+    ]);
+  });
 });

src/value-parser.ts

@@ -304,9 +304,23 @@ class ValueParser {
       if (!elementIsTupleOrArray) {
         this.consume();
         hasOpenBracket = true;
-      } else if (this.input[this.pos + 1] === "[") {
+      } else {
+        // Element is tuple or array - need to disambiguate
+        // Save position to check if this is an empty array
+        const savedPos = this.pos;
         this.consume();
+        this.skipWhitespace();
+        if (this.peek() === "]") {
+          // Empty array []
+          this.consume();
+          return [];
+        } else if (this.peek() === "[") {
+          // Nested brackets [[ - this is the array opener
           hasOpenBracket = true;
+        } else {
+          // [ belongs to the first element, restore position
+          this.pos = savedPos;
+        }
       }
     }
 
@@ -324,7 +338,8 @@ class ValueParser {
     const result: unknown[] = [];
     while (true) {
       this.skipWhitespace();
-      result.push(this.parseValue(schema.element, false));
+
+      result.push(this.parseValue(schema.element, elementIsTupleOrArray));
       this.skipWhitespace();
 
       if (!this.consumeStr(";")) {