test: add test for parsing error in jsonc-language

Author: ota-meshi

tests/lib/language/jsonc-language.ts

@@ -0,0 +1,57 @@
+import assert from "node:assert";
+import { Linter } from "eslint";
+import plugin from "../../../lib/index.ts";
+
+/**
+ * Creates a config array for testing with the specified jsonSyntax and rules.
+ */
+function createConfig(
+  jsonSyntax: "JSON" | "JSONC" | "JSON5" | null | undefined,
+  rules: Linter.RulesRecord = {},
+): Linter.Config[] {
+  return [
+    {
+      files: ["**/*.json", "**/*.jsonc", "**/*.json5"],
+      plugins: { jsonc: plugin },
+      language: "jsonc/x",
+      languageOptions:
+        jsonSyntax != null ? { parserOptions: { jsonSyntax } } : {},
+      rules,
+    },
+  ];
+}
+
+describe("JSONC Language", () => {
+  let linter: Linter;
+
+  beforeEach(() => {
+    linter = new Linter();
+  });
+
+  describe("Normal", () => {
+    it("should not have parse errors for valid JSON", () => {
+      const code = `{"key": "value"}`;
+      const messages = linter.verify(code, createConfig("JSON"), "test.json");
+
+      assert.deepStrictEqual(messages, []);
+    });
+  });
+
+  describe("Errors", () => {
+    it("should have parse errors for invalid JSON", () => {
+      const code = `{"key": "value",}`;
+      const messages = linter.verify(code, createConfig("JSON"), "test.json");
+
+      assert.deepStrictEqual(messages, [
+        {
+          fatal: true,
+          message: "Parsing error: Unexpected token ','.",
+          line: 1,
+          column: 16,
+          ruleId: null,
+          severity: 2,
+        },
+      ]);
+    });
+  });
+});