Require a block height of at least 256

contracts/Proofs.sol

@@ -6,6 +6,7 @@ contract Proofs {
   uint256 private immutable timeout;
 
   constructor(uint256 __period, uint256 __timeout) {
+    require(block.number > 256, "Insufficient block height");
     period = __period;
     timeout = __timeout;
   }

test/Proofs.test.js

@@ -1,9 +1,9 @@
 const { expect } = require("chai")
 const { ethers } = require("hardhat")
-const { mineBlock, minedBlockNumber } = require("./evm")
 const {
   snapshot,
   revert,
+  ensureMinimumBlockHeight,
   currentTime,
   advanceTime,
   advanceTimeTo,
@@ -19,15 +19,9 @@ describe("Proofs", function () {
 
   let proofs
 
-  async function ensureEnoughBlockHistory() {
-    while ((await minedBlockNumber()) < 256) {
-      await mineBlock()
-    }
-  }
-
   beforeEach(async function () {
     await snapshot()
-    await ensureEnoughBlockHistory()
+    await ensureMinimumBlockHeight(256)
     const Proofs = await ethers.getContractFactory("TestProofs")
     proofs = await Proofs.deploy(period, timeout)
   })

test/Storage.test.js

@@ -2,8 +2,7 @@ const { expect } = require("chai")
 const { ethers, deployments } = require("hardhat")
 const { exampleRequest, exampleOffer } = require("./examples")
 const {
-  mineBlock,
+  ensureMinimumBlockHeight,
-  minedBlockNumber,
   advanceTime,
   advanceTimeTo,
   currentTime,
@@ -24,15 +23,10 @@ describe("Storage", function () {
     storage = storage.connect(account)
   }
 
-  async function ensureEnoughBlockHistory() {
-    while ((await minedBlockNumber()) < 256) {
-      await mineBlock()
-    }
-  }
-
   beforeEach(async function () {
     ;[client, host] = await ethers.getSigners()
 
+    await ensureMinimumBlockHeight(256)
     await deployments.fixture(["TestToken", "Storage"])
     token = await ethers.getContract("TestToken")
     storage = await ethers.getContract("Storage")
@@ -61,8 +55,6 @@ describe("Storage", function () {
     switchAccount(client)
     await storage.selectOffer(offerId(offer))
     id = offerId(offer)
-
-    await ensureEnoughBlockHistory()
   })
 
   describe("starting the contract", function () {

test/evm.js

@@ -22,6 +22,12 @@ async function minedBlockNumber() {
   return await ethers.provider.getBlockNumber()
 }
 
+async function ensureMinimumBlockHeight(height) {
+  while ((await minedBlockNumber()) < height) {
+    await mineBlock()
+  }
+}
+
 async function currentTime() {
   let block = await ethers.provider.getBlock("latest")
   return block.timestamp
@@ -44,6 +50,7 @@ module.exports = {
   revert,
   mineBlock,
   minedBlockNumber,
+  ensureMinimumBlockHeight,
   currentTime,
   advanceTime,
   advanceTimeTo,