fix: set the earliest block tag on startup when forking

src/chains/ethereum/ethereum/src/blockchain.ts

@@ -328,8 +328,14 @@ export default class Blockchain extends Emittery<BlockchainTypedEvents> {
             options.miner.blockGasLimit,
             initialAccounts
           );
-          blocks.earliest = blocks.latest =
-            await this.#blockBeingSavedPromise.then(({ block }) => block);
+          blocks.latest = await this.#blockBeingSavedPromise.then(
+            ({ block }) => block
+          );
+          // when we are forking, blocks.earliest is already set to what was
+          // retrieved from the fork
+          if (!blocks.earliest) {
+            blocks.earliest = blocks.latest;
+          }
         }
       }
 

src/chains/ethereum/ethereum/src/data-managers/block-manager.ts

@@ -15,6 +15,7 @@ import {
   TypedDatabaseTransaction
 } from "@ganache/ethereum-transaction";
 import { GanacheLevelUp } from "../database";
+import { Ethereum } from "../api-types";
 
 const LATEST_INDEX_KEY = BUFFER_ZERO;
 
@@ -274,17 +275,39 @@ export default class BlockManager extends Manager<Block> {
     await this.#blockIndexes.put(LATEST_INDEX_KEY, number);
   }
 
+  async getEarliest() {
+    const fallback = this.#blockchain.fallback;
+    if (fallback) {
+      const json = await fallback.request<Ethereum.Block<true, "public">>(
+        "eth_getBlockByNumber",
+        [Tag.earliest, true],
+        // TODO: re-enable cache once this is fixed
+        // https://github.com/trufflesuite/ganache/issues/3773
+        { disableCache: true }
+      );
+      if (json) {
+        const common = fallback.getCommonForBlockNumber(
+          this.#common,
+          BigInt(json.number)
+        );
+        return new Block(BlockManager.rawFromJSON(json, common), common);
+      }
+    } else {
+      // if we're forking, there shouldn't be an earliest block saved to the db,
+      // it's always retrieved from the fork
+      for await (const data of this.base.createValueStream({ limit: 1 })) {
+        return new Block(data as Buffer, this.#common);
+      }
+    }
+  }
+
   /**
    * Updates the this.latest and this.earliest properties with data
    * from the database.
    */
   async updateTaggedBlocks() {
     const [earliest, latestBlockNumber] = await Promise.all([
-      (async () => {
-        for await (const data of this.base.createValueStream({ limit: 1 })) {
-          return new Block(data as Buffer, this.#common);
-        }
-      })(),
+      this.getEarliest(),
       this.#blockIndexes.get(LATEST_INDEX_KEY).catch(e => null)
     ]);
 

src/chains/ethereum/ethereum/tests/forking/block.test.ts

@@ -40,6 +40,22 @@ describe("forking", function () {
       assert.deepStrictEqual(block.parentHash, remoteBlock.hash);
     });
 
+    it("after initialization our earliest block should be the fork earliest block, parentHash should match", async () => {
+      const res = await request.post(URL).send({
+        jsonrpc: "2.0",
+        id: "1",
+        method: "eth_getBlockByNumber",
+        params: ["earliest", true]
+      });
+      const remoteBlock = JSON.parse(res.text).result;
+      const block = await provider.send("eth_getBlockByNumber", [
+        "earliest",
+        true
+      ]);
+      assert.deepStrictEqual(parseInt(block.number), parseInt(remoteBlock.number));
+      assert.deepStrictEqual(block.hash, remoteBlock.hash);
+    });
+
     //todo: reinstate this test after https://github.com/trufflesuite/ganache/issues/3616 is fixed
     it.skip("should get a block from the original chain", async () => {
       const res = await request.post(URL).send({