From 5a990106b080e2020d2f9d8059ab2ed83aa1b1d0 Mon Sep 17 00:00:00 2001
From: Anthony GAEREMYNCK <1@anthony.sh>
Date: Thu, 30 Jul 2026 09:07:26 +0200
Subject: [PATCH] feat: add image converter family (sharp)

Regenerates the sample.png test fixture via sharp itself: the
hand-encoded base64 PNG from the plan had valid magic bytes (enough to
fool file-type's signature check) but was malformed past the header,
which libpng rejected as soon as sharp actually tried to decode it.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
---
 src/converters/image.js       |  25 ++++++++++++++++++
 test/converters/image.test.js |  47 ++++++++++++++++++++++++++++++++++
 test/fixtures/sample.png      | Bin 68 -> 95 bytes
 3 files changed, 72 insertions(+)
 create mode 100644 src/converters/image.js
 create mode 100644 test/converters/image.test.js

diff --git a/src/converters/image.js b/src/converters/image.js
new file mode 100644
index 0000000..6c4086e
--- /dev/null
+++ b/src/converters/image.js
@@ -0,0 +1,25 @@
+import sharp from 'sharp';
+import { register } from './registry.js';
+
+const IMAGE_FORMATS = ['jpg', 'jpeg', 'png', 'webp', 'gif', 'tiff', 'avif'];
+
+function sharpFormatName(format) {
+  return format === 'jpg' ? 'jpeg' : format;
+}
+
+export function registerImageConverters() {
+  for (const sourceFormat of IMAGE_FORMATS) {
+    for (const targetFormat of IMAGE_FORMATS) {
+      if (sourceFormat === targetFormat) continue;
+
+      register({
+        family: 'image',
+        sourceFormat,
+        targetFormat,
+        convert: async (inputPath, outputPath) => {
+          await sharp(inputPath).toFormat(sharpFormatName(targetFormat)).toFile(outputPath);
+        },
+      });
+    }
+  }
+}
diff --git a/test/converters/image.test.js b/test/converters/image.test.js
new file mode 100644
index 0000000..684e311
--- /dev/null
+++ b/test/converters/image.test.js
@@ -0,0 +1,47 @@
+import { describe, it, expect, beforeAll, afterAll } from 'vitest';
+import fs from 'node:fs/promises';
+import path from 'node:path';
+import os from 'node:os';
+import { registerImageConverters } from '../../src/converters/image.js';
+import { resolve, listTargetFormats } from '../../src/converters/registry.js';
+import { detectInputMime } from '../../src/mime.js';
+
+let tmpDir;
+
+beforeAll(async () => {
+  registerImageConverters();
+  tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), 'converter-image-'));
+});
+
+afterAll(async () => {
+  await fs.rm(tmpDir, { recursive: true, force: true });
+});
+
+describe('image converters', () => {
+  it('registers every pair among the supported formats', () => {
+    const targets = listTargetFormats('png').sort();
+    expect(targets).toEqual(['avif', 'gif', 'jpeg', 'jpg', 'tiff', 'webp']);
+  });
+
+  it('converts a PNG fixture to WebP', async () => {
+    const inputPath = path.join(import.meta.dirname, '..', 'fixtures', 'sample.png');
+    const outputPath = path.join(tmpDir, 'output.webp');
+    const entry = resolve('png', 'webp');
+
+    await entry.convert(inputPath, outputPath);
+
+    const detected = await detectInputMime(outputPath);
+    expect(detected.mime).toBe('image/webp');
+  });
+
+  it('converts a PNG fixture to JPG', async () => {
+    const inputPath = path.join(import.meta.dirname, '..', 'fixtures', 'sample.png');
+    const outputPath = path.join(tmpDir, 'output.jpg');
+    const entry = resolve('png', 'jpg');
+
+    await entry.convert(inputPath, outputPath);
+
+    const detected = await detectInputMime(outputPath);
+    expect(detected.mime).toBe('image/jpeg');
+  });
+});
diff --git a/test/fixtures/sample.png b/test/fixtures/sample.png
index 520b38b7bfbb918d01382f7f5abbd6714eda7eac..6e2747d6f3dd4a57f582ea7fdfc008aa4b870b78 100644
GIT binary patch
literal 95
zcmeAS@N?(olHy`uVBq!ia0vp^EFjFm1SHiab7}%9&H|6fVg?507a+{IwK^ypC@ARZ
o;uyj)Gx^8)0}SpQVsU&7>n8Jm+))|r29#v*boFyt=akR{06fkWzyJUM

literal 68
zcmeAS@N?(olHy`uVBq!ia0vp^j3CUx1|;Q0k8}blZci7-kcv6U2@FgO46F={FMr*+
Q0TgENboFyt=akR{0DRC61ONa4