feat: add DjVu conversion support (#612)

* feat: add DjVu conversion support

* fix: support DjVu aliases and prioritize converter

* fix: restore DjVu converter priority

* [autofix.ci] apply automated fixes

---------

Co-authored-by: Alex N <alex@alex-n.net>
Co-authored-by: Emrik Östling <emrik.ostling@gmail.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

Dockerfile

@@ -56,6 +56,7 @@ RUN apt-get update && apt-get install -y \
   calibre \
   dasel \
   dcraw \
+  djvulibre-bin \
   dvisvgm \
   ffmpeg \
   ghostscript \

README.md

@@ -36,6 +36,7 @@ A self-hosted online file converter. Supports over a thousand different formats.
 | [Calibre](https://calibre-ebook.com/)                           | E-books          | 26            | 19          |
 | [LibreOffice](https://www.libreoffice.org/)                     | Documents        | 41            | 22          |
 | [Dasel](https://github.com/TomWright/dasel)                     | Data Files       | 5             | 4           |
+| [DjVuLibre](https://djvu.sourceforge.net/)                      | Documents        | 2             | 2           |
 | [Pandoc](https://pandoc.org/)                                   | Documents        | 43            | 65          |
 | [msgconvert](https://github.com/mvz/email-outlook-message-perl) | Outlook          | 1             | 1           |
 | VCF to CSV                                                      | Contacts         | 1             | 1           |

src/converters/djvu.ts

@@ -0,0 +1,39 @@
+import { execFile as execFileOriginal } from "node:child_process";
+import type { ExecFileFn } from "./types";
+
+export const properties = {
+  from: {
+    document: ["djvu", "djv"],
+  },
+  to: {
+    document: ["pdf", "tiff"],
+  },
+};
+
+export function convert(
+  filePath: string,
+  _fileType: string,
+  convertTo: string,
+  targetPath: string,
+  _options?: unknown,
+  execFile: ExecFileFn = execFileOriginal,
+): Promise<string> {
+  return new Promise((resolve, reject) => {
+    execFile("ddjvu", [`-format=${convertTo}`, filePath, targetPath], (error, stdout, stderr) => {
+      if (error) {
+        reject(`error: ${error}${stderr ? `\nstderr: ${stderr}` : ""}`);
+        return;
+      }
+
+      if (stdout) {
+        console.log(`stdout: ${stdout}`);
+      }
+
+      if (stderr) {
+        console.error(`stderr: ${stderr}`);
+      }
+
+      resolve("Done");
+    });
+  });
+}

src/converters/main.ts

@@ -7,6 +7,7 @@ import { normalizeFiletype, normalizeOutputFiletype } from "../helpers/normalize
 import { convert as convertassimp, properties as propertiesassimp } from "./assimp";
 import { convert as convertCalibre, properties as propertiesCalibre } from "./calibre";
 import { convert as convertDasel, properties as propertiesDasel } from "./dasel";
+import { convert as convertDjvu, properties as propertiesDjvu } from "./djvu";
 import { convert as convertDvisvgm, properties as propertiesDvisvgm } from "./dvisvgm";
 import { convert as convertFFmpeg, properties as propertiesFFmpeg } from "./ffmpeg";
 import {
@@ -92,6 +93,10 @@ const properties: Record<
     properties: propertiesDasel,
     converter: convertDasel,
   },
+  djvu: {
+    properties: propertiesDjvu,
+    converter: convertDjvu,
+  },
   libreoffice: {
     properties: propertiesLibreOffice,
     converter: convertLibreOffice,

tests/converters/djvu.test.ts

@@ -0,0 +1,36 @@
+import type { ExecFileException } from "node:child_process";
+import { expect, test } from "bun:test";
+import { convert, properties } from "../../src/converters/djvu";
+import type { ExecFileFn } from "../../src/converters/types";
+import { runCommonTests } from "./helpers/commonTests";
+
+runCommonTests(convert);
+
+test("advertises DjVu to PDF and TIFF conversions", () => {
+  expect(properties).toEqual({
+    from: { document: ["djvu", "djv"] },
+    to: { document: ["pdf", "tiff"] },
+  });
+});
+
+for (const format of ["pdf", "tiff"]) {
+  test(`calls ddjvu with the ${format} output format`, async () => {
+    let command = "";
+    let args: string[] = [];
+    const mockExecFile: ExecFileFn = (
+      cmd: string,
+      commandArgs: string[],
+      callback: (err: ExecFileException | null, stdout: string, stderr: string) => void,
+    ) => {
+      command = cmd;
+      args = commandArgs;
+      callback(null, "", "");
+    };
+
+    await expect(
+      convert("input.djvu", "djvu", format, `output.${format}`, undefined, mockExecFile),
+    ).resolves.toBe("Done");
+    expect(command).toBe("ddjvu");
+    expect(args).toEqual([`-format=${format}`, "input.djvu", `output.${format}`]);
+  });
+}