Fix v3 best-fit sizing incorrectly requiring upscaling check

src/calculator/v3.ts

@@ -31,7 +31,7 @@ export class Calculator extends Base {
     }
     super.size(v);
     const { region, size, upscale } = this._parsedInfo;
-    if (!upscale) {
+    if (!upscale && size.fit !== 'inside') {
       if (size.width > region.width || size.height > region.height) {
         throw new IIIFError('Requested size requires upscaling', {
           statusCode: 400

tests/v3/calculator.test.ts

@@ -6,7 +6,7 @@
 import { Calculator } from '../../src/calculator/v3';
 import { IIIFError } from '../../src/error';
 import values from '../fixtures/iiif-values';
 const { v3: { qualities, formats, regions, sizes, rotations } } = values as any;
 
 let subject;
 
@@ -154,6 +154,40 @@
       subject.region('pct:50,50,25,25').size('^512,384').rotation('45').quality('default').format('jpg', 600);
       assert.deepEqual(subject.info(), expected);
     });
+
+    it('allows best-fit sizing larger than source without upscaling error', () => {
+      subject = new Calculator({ width: 1024, height: 768 });
+
+      // !9000,9000 should not throw even though dimensions exceed source
+      assert.doesNotThrow(() => {
+        subject
+          .region('full')
+          .size('!9000,9000')
+          .rotation('0')
+          .quality('default')
+          .format('jpg');
+      }, IIIFError);
+
+      const result = subject.info();
+      assert.equal(result.size.fit, 'inside');
+      assert.equal(result.size.width, 9000);
+      assert.equal(result.size.height, 9000);
+      assert.equal(result.upscale, false);
+    });
+
+    it('throws upscaling error for exact size larger than source', () => {
+      subject = new Calculator({ width: 1024, height: 768 });
+
+      // 9000,9000 without ! should throw upscaling error
+      assert.throws(() => {
+        subject
+          .region('full')
+          .size('9000,9000')
+          .rotation('0')
+          .quality('default')
+          .format('jpg');
+      }, IIIFError);
+    });
   });
 
   describe('density', () => {