fix: crop horizontally when aspect ratio is reduced without width or …

…height (#753)

.changeset/fuzzy-beers-hang.md

@@ -0,0 +1,5 @@
+---
+'imagetools-core': patch
+---
+
+fix: correctly reduce the aspect ratio when no width or height is provided

packages/core/src/transforms/__tests__/resize.spec.ts

@@ -283,6 +283,16 @@ describe('aspect', () => {
       expect(await image.toBuffer()).toMatchImageSnapshot()
     })
 
+    test('w/ crop horizontally', async () => {
+      // @ts-expect-error we know this is safe
+      const { image } = await applyTransforms([resize({ aspect: '1:2' }, dirCtx)], img)
+
+      const { width = 0, height = 0 } = await sharp(await image.toBuffer()).metadata()
+      expect(width / height).toEqual(1 / 2)
+
+      expect(await image.toBuffer()).toMatchImageSnapshot()
+    })
+
     test('w/ fit', async () => {
       //@ts-expect-error we know this is safe
       const { image } = await applyTransforms([resize({ aspect: '4:3', fit: 'contain' }, dirCtx)], img)

packages/core/src/transforms/resize.ts

@@ -74,7 +74,7 @@ export const resize: TransformFactory<ResizeOptions> = (config, context) => {
         finalWidth = originalWidth
       } else {
         finalHeight = originalHeight
-        finalWidth = originalHeight / aspect
+        finalWidth = originalHeight * aspect
       }
     } else if (width && height) {
       // width & height BOTH given, need to look at fit