Add end-to-end test of rust gbt against results from Core

backend/src/__tests__/gbt/gbt-tests.ts

@@ -0,0 +1,27 @@
+import fs from 'fs';
+import { GbtGenerator } from '../../../rust-gbt';
+import path from 'path';
+
+const baseline = require('./test-data/target-template.json');
+const testVector = require('./test-data/test-data-ids.json');
+const vectorUidMap: Map<number, string> = new Map(testVector.map(x => [x[0], x[1]]));
+const vectorTxidMap: Map<string, number>  = new Map(testVector.map(x => [x[1], x[0]]));
+// Note that this test buffer is specially constructed
+// such that uids are assigned in numerical txid order
+// so that ties break the same way as in Core's implementation
+const vectorBuffer: ArrayBuffer = fs.readFileSync(path.join(__dirname, './', './test-data/test-buffer.bin'));
+
+describe('Rust GBT', () => {
+  test('should produce the same template as getBlockTemplate from Bitcoin Core', async () => {
+    const rustGbt = new GbtGenerator();
+    const result = await rustGbt.make(new Uint8Array(vectorBuffer));
+
+    const blocks: [string, number][][] = result.blocks.map(block => {
+      return block.map(uid => [vectorUidMap.get(uid) || 'missing', uid]);
+    });
+    const template = baseline.map(tx => [tx.txid, vectorTxidMap.get(tx.txid)]);
+
+    expect(blocks[0].length).toEqual(baseline.length);
+    expect(blocks[0]).toEqual(template);
+  });
+});