VAL-132 Allow cancellation of full requested balance

contracts/libraries/PoolLib.sol

@@ -548,14 +548,7 @@ library PoolLib {
         IPoolWithdrawState memory state,
         uint256 requestCancellationFeeBps
     ) public pure returns (uint256) {
-        uint256 sharesRemaining = state.requestedShares + state.eligibleShares;
-
-        uint256 sharesFee = calculateCancellationFee(
-            sharesRemaining,
-            requestCancellationFeeBps
-        );
-
-        return Math.max(sharesRemaining - sharesFee, 0);
+        return state.requestedShares + state.eligibleShares;
     }
 
     /**

test/libraries/PoolLib.test.ts

@@ -879,7 +879,7 @@ describe("PoolLib", () => {
       ).to.equal(72);
     });
 
-    it("returns the number of shares minus fees", async () => {
+    it("returns the number of shares irrespective of fees ", async () => {
       const { poolLibWrapper } = await loadFixture(deployFixture);
 
       const fees = 1200; // 12%
@@ -892,7 +892,7 @@ describe("PoolLib", () => {
 
       expect(
         await poolLibWrapper.calculateMaxCancellation(withdrawState, fees)
-      ).to.equal(63);
+      ).to.equal(72);
     });
   });
 });

test/scenarios/pool/withdraw-request.test.ts

@@ -148,15 +148,43 @@ describe("Withdraw Requests", () => {
     expect(await pool.maxWithdraw(bobLender.address)).to.equal(6);
 
     // Cancel a request
-    expect(await pool.maxRequestCancellation(aliceLender.address)).to.equal(16);
-    expect(await pool.maxRequestCancellation(bobLender.address)).to.equal(3);
+    expect(await pool.maxRequestCancellation(aliceLender.address)).to.equal(17);
+    expect(await pool.maxRequestCancellation(bobLender.address)).to.equal(4);
 
     // Cancel Bob's request
     const bobBalance = await pool.balanceOf(bobLender.address);
     await pool.connect(bobLender).cancelRedeemRequest(3);
 
     // Expect a fee to be paid
     expect(await pool.balanceOf(bobLender.address)).to.equal(bobBalance.sub(1));
-    expect(await pool.maxRequestCancellation(bobLender.address)).to.equal(0);
+    expect(await pool.maxRequestCancellation(bobLender.address)).to.equal(1);
+  });
+
+  it("allows canceling a full request balance", async () => {
+    const { pool, aliceLender, bobLender, withdrawController } =
+      await loadFixture(loadPoolFixture);
+
+    // Alice requests full redemption
+    await pool
+      .connect(aliceLender)
+      .requestRedeem(await pool.maxRedeemRequest(aliceLender.address));
+    expect(
+      await withdrawController.requestedBalanceOf(aliceLender.address)
+    ).to.equal(90);
+
+    // Check max request cancellation
+    expect(await pool.maxRequestCancellation(aliceLender.address)).to.equal(90);
+
+    // Cancel request
+    const txn = await pool.connect(aliceLender).cancelRedeemRequest(90);
+
+    // Check that the cancellation burned a PT in fees
+    // 1% cancellation fee of 90 == 1 token
+    await expect(txn).to.changeTokenBalance(pool, aliceLender.address, -1);
+
+    // Check requested balance is now zeroed out
+    expect(
+      await withdrawController.requestedBalanceOf(aliceLender.address)
+    ).to.equal(0);
   });
 });