test: add unit test for calibre.ts

src/converters/calibre.ts

@@ -1,4 +1,5 @@
-import { execFile } from "node:child_process";
+import { execFile as execFileOriginal } from "node:child_process";
+import { ExecFileFn } from "./types.ts";
 
 export const properties = {
   from: {
@@ -62,28 +63,24 @@ export async function convert(
   fileType: string,
   convertTo: string,
   targetPath: string,
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars
   options?: unknown,
+  execFile: ExecFileFn = execFileOriginal, // to make it mockable
 ): Promise<string> {
   return new Promise((resolve, reject) => {
-    execFile(
-      "ebook-convert",
-      [filePath, targetPath],
-      (error, stdout, stderr) => {
-        if (error) {
-          reject(`error: ${error}`);
-        }
+    execFile("ebook-convert", [filePath, targetPath], (error, stdout, stderr) => {
+      if (error) {
+        reject(`error: ${error}`);
+      }
 
-        if (stdout) {
-          console.log(`stdout: ${stdout}`);
-        }
+      if (stdout) {
+        console.log(`stdout: ${stdout}`);
+      }
 
-        if (stderr) {
-          console.error(`stderr: ${stderr}`);
-        }
+      if (stderr) {
+        console.error(`stderr: ${stderr}`);
+      }
 
-        resolve("Done");
-      },
-    );
+      resolve("Done");
+    });
   });
 }

src/converters/types.ts

@@ -3,3 +3,12 @@ export type ExecFileFn = (
   args: string[],
   callback: (err: Error | null, stdout: string, stderr: string) => void,
 ) => void;
+
+export type ConvertFnWithExecFile = (
+  filePath: string,
+  fileType: string,
+  convertTo: string,
+  targetPath: string,
+  options: unknown,
+  execFileOverride?: ExecFileFn,
+) => Promise<string>;

tests/converters/assimp.test.ts

@@ -1,65 +1,19 @@
-import type { ExecFileException } from "node:child_process";
-import { expect, test } from "bun:test";
+import { test } from "bun:test";
 import { convert } from "../../src/converters/assimp.ts";
-import { ExecFileFn } from "../../src/converters/types.ts";
+import {
+  runConvertFailTest,
+  runConvertLogsStderror,
+  runConvertSuccessTest,
+} from "../helpers/converters.test.ts";
 
 test("convert resolves when execFile succeeds", async () => {
-  const originalConsoleLog = console.log;
-
-  let loggedMessage = "";
-  console.log = (msg) => {
-    loggedMessage = msg;
-  };
-
-  const mockExecFile: ExecFileFn = (
-    _cmd: string,
-    _args: string[],
-    callback: (err: ExecFileException | null, stdout: string, stderr: string) => void,
-  ) => {
-    callback(null, "Fake stdout", "");
-  };
-
-  const result = await convert("input.obj", "obj", "stl", "output.stl", undefined, mockExecFile);
-
-  console.log = originalConsoleLog;
-
-  expect(result).toBe("Done");
-  expect(loggedMessage).toBe("stdout: Fake stdout");
+  await runConvertSuccessTest(convert);
 });
 
 test("convert rejects when execFile fails", async () => {
-  const mockExecFile: ExecFileFn = (
-    _cmd: string,
-    _args: string[],
-    callback: (err: ExecFileException | null, stdout: string, stderr: string) => void,
-  ) => {
-    callback(new Error("Test error"), "", "");
-  };
-
-  expect(convert("input.obj", "obj", "stl", "output.stl", undefined, mockExecFile)).rejects.toMatch(
-    /error: Error: Test error/,
-  );
+  await runConvertFailTest(convert);
 });
 
 test("convert logs stderr when present", async () => {
-  const originalConsoleError = console.error;
-
-  let loggedMessage = "";
-  console.error = (msg) => {
-    loggedMessage = msg;
-  };
-
-  const mockExecFile = (
-    _cmd: string,
-    _args: string[],
-    cb: (err: Error | null, stdout: string, stderr: string) => void,
-  ) => {
-    cb(null, "", "Fake stderr");
-  };
-
-  await convert("file.obj", "obj", "stl", "out.stl", undefined, mockExecFile);
-
-  console.error = originalConsoleError;
-
-  expect(loggedMessage).toBe("stderr: Fake stderr");
+  await runConvertLogsStderror(convert);
 });

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);
+});

tests/helpers/converters.test.ts

@@ -0,0 +1,64 @@
+import type { ExecFileException } from "node:child_process";
+import { expect } from "bun:test";
+import { ConvertFnWithExecFile, ExecFileFn } from "../../src/converters/types.ts";
+
+export async function runConvertSuccessTest(convertFn: ConvertFnWithExecFile) {
+  const originalConsoleLog = console.log;
+
+  let loggedMessage = "";
+  console.log = (msg) => {
+    loggedMessage = msg;
+  };
+
+  const mockExecFile: ExecFileFn = (
+    _cmd: string,
+    _args: string[],
+    callback: (err: ExecFileException | null, stdout: string, stderr: string) => void,
+  ) => {
+    callback(null, "Fake stdout", "");
+  };
+
+  const result = await convertFn("input.obj", "obj", "stl", "output.stl", undefined, mockExecFile);
+
+  console.log = originalConsoleLog;
+
+  expect(result).toBe("Done");
+  expect(loggedMessage).toBe("stdout: Fake stdout");
+}
+
+export async function runConvertFailTest(convertFn: ConvertFnWithExecFile) {
+  const mockExecFile: ExecFileFn = (
+    _cmd: string,
+    _args: string[],
+    callback: (err: ExecFileException | null, stdout: string, stderr: string) => void,
+  ) => {
+    callback(new Error("Test error"), "", "");
+  };
+
+  expect(
+    convertFn("input.obj", "obj", "stl", "output.stl", undefined, mockExecFile),
+  ).rejects.toMatch(/error: Error: Test error/);
+}
+
+export async function runConvertLogsStderror(convertFn: ConvertFnWithExecFile) {
+  const originalConsoleError = console.error;
+
+  let loggedMessage = "";
+  console.error = (msg) => {
+    loggedMessage = msg;
+  };
+
+  const mockExecFile = (
+    _cmd: string,
+    _args: string[],
+    cb: (err: Error | null, stdout: string, stderr: string) => void,
+  ) => {
+    cb(null, "", "Fake stderr");
+  };
+
+  await convertFn("file.obj", "obj", "stl", "out.stl", undefined, mockExecFile);
+
+  console.error = originalConsoleError;
+
+  expect(loggedMessage).toBe("stderr: Fake stderr");
+}