test: add unit test for calibre.ts

tests/converters/calibre.test.ts

@@ -0,0 +1,19 @@
+import { test } from "bun:test";
+import { convert } from "../../src/converters/calibre.ts";
+import {
+  runConvertFailTest,
+  runConvertLogsStderror,
+  runConvertSuccessTest,
+} from "../helpers/converters.test.ts";
+
+test("convert resolves when execFile succeeds", async () => {
+  await runConvertSuccessTest(convert);
+});
+
+test("convert rejects when execFile fails", async () => {
+  await runConvertFailTest(convert);
+});
+
+test("convert logs stderr when present", async () => {
+  await runConvertLogsStderror(convert);
+});