vault: fix flaky time sensitive tests

Ensures that setting of lock and starting of
flow happen in the same block.
Therefore hardhat cannot occasionally increase
the timestamp between the two operations.
This makes predicting the balances over time
much easier.

test/Vault.tests.js

@@ -6,6 +6,7 @@ const {
   advanceTimeTo,
   mine,
   setAutomine,
+  setNextBlockTimestamp,
   snapshot,
   revert,
 } = require("./evm")
@@ -438,13 +439,17 @@ describe("Vault", function () {
       let maximum
 
       beforeEach(async function () {
-        expiry = (await currentTime()) + 80
-        maximum = expiry + 20
+        const beginning = (await currentTime()) + 10
+        expiry = beginning + 80
+        maximum = beginning + 100
+        await setAutomine(false)
+        await setNextBlockTimestamp(beginning)
         await vault.lock(context, expiry, maximum)
       })
 
       it("moves tokens over time", async function () {
         await vault.flow(context, sender, receiver, 2)
+        mine()
         const start = await currentTime()
         await advanceTimeTo(start + 2)
         expect(await getBalance(sender)).to.equal(deposit - 4)
@@ -455,7 +460,6 @@ describe("Vault", function () {
       })
 
       it("can move tokens to several different recipients", async function () {
-        await setAutomine(false)
         await vault.flow(context, sender, receiver, 1)
         await vault.flow(context, sender, receiver2, 2)
         await mine()
@@ -471,7 +475,6 @@ describe("Vault", function () {
       })
 
       it("allows flows to be diverted to other recipient", async function () {
-        await setAutomine(false)
         await vault.flow(context, sender, receiver, 3)
         await vault.flow(context, receiver, receiver2, 1)
         await mine()
@@ -487,7 +490,6 @@ describe("Vault", function () {
       })
 
       it("allows flow to be reversed back to the sender", async function () {
-        await setAutomine(false)
         await vault.flow(context, sender, receiver, 3)
         await vault.flow(context, receiver, sender, 3)
         await mine()
@@ -501,12 +503,11 @@ describe("Vault", function () {
       })
 
       it("can change flows over time", async function () {
-        await setAutomine(false)
         await vault.flow(context, sender, receiver, 1)
         await vault.flow(context, sender, receiver2, 2)
         await mine()
         const start = await currentTime()
-        advanceTimeTo(start + 4)
+        setNextBlockTimestamp(start + 4)
         await vault.flow(context, receiver2, receiver, 1)
         await mine()
         expect(await getBalance(sender)).to.equal(deposit - 12)
@@ -524,6 +525,7 @@ describe("Vault", function () {
 
       it("designates tokens that flow for the recipient", async function () {
         await vault.flow(context, sender, receiver, 3)
+        await mine()
         const start = await currentTime()
         await advanceTimeTo(start + 7)
         expect(await vault.getDesignatedBalance(context, receiver)).to.equal(21)
@@ -531,6 +533,7 @@ describe("Vault", function () {
 
       it("stops flowing when lock expires", async function () {
         await vault.flow(context, sender, receiver, 2)
+        await mine()
         const start = await currentTime()
         await advanceTimeTo(expiry)
         const total = (expiry - start) * 2
@@ -543,8 +546,10 @@ describe("Vault", function () {
 
       it("flows longer when lock is extended", async function () {
         await vault.flow(context, sender, receiver, 2)
+        await mine()
         const start = await currentTime()
         await vault.extendLock(context, maximum)
+        await mine()
         await advanceTimeTo(maximum)
         const total = (maximum - start) * 2
         expect(await getBalance(sender)).to.equal(deposit - total)
@@ -555,12 +560,14 @@ describe("Vault", function () {
       })
 
       it("rejects negative flows", async function () {
+        setAutomine(true)
         await expect(
           vault.flow(context, sender, receiver, -1)
         ).to.be.revertedWith("NegativeFlow")
       })
 
       it("rejects flow when insufficient available tokens", async function () {
+        setAutomine(true)
         await expect(
           vault.flow(context, sender, receiver, 11)
         ).to.be.revertedWith("InsufficientBalance")
@@ -568,6 +575,7 @@ describe("Vault", function () {
 
       it("rejects total flows exceeding available tokens", async function () {
         await vault.flow(context, sender, receiver, 10)
+        setAutomine(true)
         await expect(
           vault.flow(context, sender, receiver, 1)
         ).to.be.revertedWith("InsufficientBalance")
@@ -575,9 +583,8 @@ describe("Vault", function () {
 
       it("cannot flow designated tokens", async function () {
         await vault.designate(context, sender, 500)
-        await expect(
-          vault.flow(context, sender, receiver, 5)
-        ).not.to.be.reverted
+        await vault.flow(context, sender, receiver, 5)
+        setAutomine(true)
         await expect(
           vault.flow(context, sender, receiver, 1)
         ).to.be.revertedWith("InsufficientBalance")
@@ -585,9 +592,8 @@ describe("Vault", function () {
 
       it("cannot transfer tokens that are flowing", async function () {
         await vault.flow(context, sender, receiver, 5)
-        await expect(
-          vault.transfer(context, sender, receiver, 500)
-        ).not.to.be.reverted
+        setAutomine(true)
+        await vault.transfer(context, sender, receiver, 500)
         await expect(
           vault.transfer(context, sender, receiver, 1)
         ).to.be.revertedWith("InsufficientBalance")
@@ -595,15 +601,17 @@ describe("Vault", function () {
 
       it("cannot burn tokens that are flowing", async function () {
         await vault.flow(context, sender, receiver, 5)
-        await expect(
-          vault.burn(context, sender)
-        ).to.be.revertedWith("CannotBurnFlowingTokens")
-        await expect(
-          vault.burn(context, receiver)
-        ).to.be.revertedWith("CannotBurnFlowingTokens")
+        setAutomine(true)
+        await expect(vault.burn(context, sender)).to.be.revertedWith(
+          "CannotBurnFlowingTokens"
+        )
+        await expect(vault.burn(context, receiver)).to.be.revertedWith(
+          "CannotBurnFlowingTokens"
+        )
       })
 
       it("can burn tokens that are no longer flowing", async function () {
+        setAutomine(true)
         await vault.flow(context, sender, receiver, 5)
         await vault.flow(context, receiver, sender, 5)
         await expect(vault.burn(context, sender)).not.to.be.reverted

test/evm.js

@@ -41,10 +41,14 @@ async function advanceTime(seconds) {
 }
 
 async function advanceTimeTo(timestamp) {
-  await ethers.provider.send("evm_setNextBlockTimestamp", [timestamp])
+  await setNextBlockTimestamp(timestamp)
   await mine()
 }
 
+async function setNextBlockTimestamp(timestamp) {
+  await ethers.provider.send("evm_setNextBlockTimestamp", [timestamp])
+}
+
 module.exports = {
   snapshot,
   revert,
@@ -54,4 +58,5 @@ module.exports = {
   currentTime,
   advanceTime,
   advanceTimeTo,
+  setNextBlockTimestamp,
 }