[refactor] do not expose cancelled logic externally

contracts/Marketplace.sol

@@ -124,7 +124,7 @@ contract Marketplace is Collateral, Proofs {
   /// @dev Handles the case when a request may have been cancelled, but the client has not withdrawn its funds yet, and therefore the state has not yet been updated.
   /// @param requestId the id of the request
   /// @return true if request is cancelled
-  function isCancelled(bytes32 requestId) public view returns (bool) {
+  function _isCancelled(bytes32 requestId) internal view returns (bool) {
     RequestContext memory context = requestContexts[requestId];
     return
       context.state == RequestState.Cancelled ||
@@ -134,15 +134,23 @@ contract Marketplace is Collateral, Proofs {
       );
   }
 
+  /// @notice Return id of request that slot belongs to
+  /// @dev Returns requestId that is mapped to the slotId
+  /// @param slotId id of the slot
+  /// @return if of the request the slot belongs to
+  function _getRequestIdForSlot(bytes32 slotId) internal view returns (bytes32) {
+    Slot memory slot = _slot(slotId);
+    require(slot.requestId != 0, "Missing request id");
+    return slot.requestId;
+  }
+
   /// @notice Return true if the request state the slot belongs to is RequestState.Cancelled or if the request expiry time has elapsed and the request was never started.
   /// @dev Handles the case when a request may have been cancelled, but the client has not withdrawn its funds yet, and therefore the state has not yet been updated.
   /// @param slotId the id of the slot
   /// @return true if request is cancelled
-  function isSlotCancelled(bytes32 slotId) public view returns (bool) {
-    Slot memory slot = slots[slotId];
-    require(slot.host != address(0), "Slot empty");
-    require(slot.requestId != 0, "Missing request id");
-    return isCancelled(slot.requestId);
+  function _isSlotCancelled(bytes32 slotId) internal view returns (bool) {
+    bytes32 requestId = _getRequestIdForSlot(slotId);
+    return _isCancelled(requestId);
   }
 
   function _host(bytes32 slotId) internal view returns (address) {
@@ -153,6 +161,12 @@ contract Marketplace is Collateral, Proofs {
     return requests[id];
   }
 
+  function _slot(bytes32 slotId) internal view returns (Slot memory) {
+    Slot memory slot = slots[slotId];
+    require(slot.host != address(0), "Slot empty");
+    return slot;
+  }
+
   function proofPeriod() public view returns (uint256) {
     return _period();
   }

contracts/Storage.sol

@@ -36,6 +36,18 @@ contract Storage is Collateral, Marketplace {
     return _request(requestId);
   }
 
+  function getSlot(bytes32 slotId) public view returns (Slot memory) {
+    return _slot(slotId);
+  }
+
+  function isCancelled(bytes32 requestId) public view returns(bool) {
+    return _isCancelled(requestId);
+  }
+
+  function isSlotCancelled(bytes32 slotId) public view returns (bool) {
+    return _isSlotCancelled(slotId);
+  }
+
   function getHost(bytes32 requestId) public view returns (address) {
     return _host(requestId);
   }

test/Marketplace.test.js

@@ -351,26 +351,6 @@ describe("Marketplace", function () {
       Failed: 4,
     }
 
-    it("isCancelled is true once request is cancelled", async function () {
-      await expect(await marketplace.isCancelled(slot.request)).to.equal(false)
-      await waitUntilExpired(request.expiry)
-      await expect(await marketplace.isCancelled(slot.request)).to.equal(true)
-    })
-
-    it("isSlotCancelled fails when slot is empty", async function () {
-      await expect(
-        marketplace.isSlotCancelled(slotId(slot))
-      ).to.be.revertedWith("Slot empty")
-    })
-
-    it("isSlotCancelled is true once request is cancelled", async function () {
-      await marketplace.fillSlot(slot.request, slot.index, proof)
-      await waitUntilExpired(request.expiry)
-      await expect(await marketplace.isSlotCancelled(slotId(slot))).to.equal(
-        true
-      )
-    })
-
     it("state is Cancelled when client withdraws funds", async function () {
       await expect(await marketplace.state(slot.request)).to.equal(
         RequestState.New

test/Storage.test.js

@@ -7,6 +7,7 @@ const { advanceTime, advanceTimeTo, currentTime } = require("./evm")
 const { requestId, slotId } = require("./ids")
 const { periodic } = require("./time")
 const { price } = require("./price")
+const { waitUntilExpired } = require("./marketplace")
 
 describe("Storage", function () {
   const proof = hexlify(randomBytes(42))
@@ -121,6 +122,25 @@ describe("Storage", function () {
       ).to.be.revertedWith("Request was cancelled")
     })
   })
+  describe("contract state", function () {
+    it("isCancelled is true once request is cancelled", async function () {
+      await expect(await storage.isCancelled(slot.request)).to.equal(false)
+      await waitUntilExpired(request.expiry)
+      await expect(await storage.isCancelled(slot.request)).to.equal(true)
+    })
+
+    it("isSlotCancelled fails when slot is empty", async function () {
+      await expect(storage.isSlotCancelled(slotId(slot))).to.be.revertedWith(
+        "Slot empty"
+      )
+    })
+
+    it("isSlotCancelled is true once request is cancelled", async function () {
+      await storage.fillSlot(slot.request, slot.index, proof)
+      await waitUntilExpired(request.expiry)
+      await expect(await storage.isSlotCancelled(slotId(slot))).to.equal(true)
+    })
+  })
 })
 
 // TODO: implement checking of actual proofs of storage, instead of dummy bool