optimize share submission path

src/models/MiningJob.spec.ts

@@ -83,6 +83,33 @@ describe('MiningJob', () => {
         expect(updatedBlock.version).toBe(jobTemplate.block.version);
     });
 
+    it('should build the same header as the full block update path', () => {
+        const versionMask = parseInt('00002000', 16);
+        const nonce = parseInt('ed460d91', 16);
+        const extraNonce1 = '57a6f098';
+        const extraNonce2 = 'c708000000000000';
+        const timestamp = parseInt(MockRecording1.TIME, 16);
+
+        const updatedBlock = job.copyAndUpdateBlock(
+            jobTemplate,
+            versionMask,
+            nonce,
+            extraNonce1,
+            extraNonce2,
+            timestamp
+        );
+        const fastHeader = job.buildHeaderBuffer(
+            jobTemplate,
+            versionMask,
+            nonce,
+            extraNonce1,
+            extraNonce2,
+            timestamp
+        );
+
+        expect(fastHeader.equals(updatedBlock.toBuffer(true))).toBe(true);
+    });
+
     it('should expose coinbase helpers for downstream validation', () => {
         const notify = JSON.parse(job.response(jobTemplate));