originMultiplier metadata

.lintstagedrc

@@ -1,6 +1,3 @@
 {
-	"src/**/*.{ts,tsx}": [
-		"trigen-scripts lint:ts",
-		"git add"
-	]
+	"src/**/*.{ts,tsx}": "trigen-scripts lint:ts"
 }

src/ISrcsetVinyl.ts

@@ -4,6 +4,8 @@ import {
 } from 'sharp';
 
 export default interface ISrsetVinyl extends Vinyl {
-	metadata?: Metadata;
+	metadata?: Metadata & {
+		originMultiplier?: number;
+	};
 	postfix?: string;
 }

src/helpers.ts

@@ -48,7 +48,11 @@ export async function attachMetadata(source: Vinyl, force = false): Promise<ISrs
 	}
 
 	try {
+
+		const originMultiplier = source?.metadata?.originMultiplier;
+
 		source.metadata = await Sharp(source.contents as Buffer).metadata();
+		source.metadata.originMultiplier = originMultiplier;
 	} catch (err) {
 		return source;
 	}

src/index.ts

@@ -198,10 +198,15 @@ export default class SrcsetGenerator {
 
 		if (width !== null) {
 
-			const calculatedWidth = originWidth && width <= 1
+			const isMultiplier = width <= 1;
+			const calculatedWidth = originWidth && isMultiplier
 				? Math.ceil(width * originWidth)
 				: width;
 
+			if (isMultiplier) {
+				target.metadata.originMultiplier = width;
+			}
+
 			this.addPostfix(target, calculatedWidth, width, config.postfix);
 
 			if (calculatedWidth < originWidth) {

test/SrcsetGenerator.spec.ts

@@ -222,5 +222,19 @@ describe('SrcsetGenerator', () => {
 				} as any))
 			).rejects.toThrow();
 		});
+
+		it('should add originMultiplier to metadate', async () => {
+
+			const [
+				x2,
+				x1
+			] = await vinylsFromAsyncIterator(srcset.generate(image, {
+				scalingUp: false,
+				width: [1, .5]
+			}));
+
+			expect(x2.metadata.originMultiplier).toBe(1);
+			expect(x1.metadata.originMultiplier).toBe(.5);
+		});
 	});
 });