test: add test when array count is zero

test/unit/lockup/shared/cancel-multiple/cancelMultiple.t.sol

@@ -24,14 +24,24 @@ abstract contract CancelMultiple_Unit_Test is Unit_Test, Lockup_Shared_Test {
     }
 
     /// @dev it should do nothing.
-    function test_RevertWhen_OnlyNullStreams() external {
+    function test_RevertWhen_ArrayCountZero() external {
+        uint256[] memory streamIds = new uint256[](0);
+        lockup.cancelMultiple(streamIds);
+    }
+
+    modifier arrayCountNotZero() {
+        _;
+    }
+
+    /// @dev it should do nothing.
+    function test_RevertWhen_OnlyNullStreams() external arrayCountNotZero {
         uint256 nullStreamId = 1729;
         uint256[] memory streamIds = Solarray.uint256s(nullStreamId);
         lockup.cancelMultiple(streamIds);
     }
 
     /// @dev it should ignore the null streams and cancel the non-null ones.
-    function test_RevertWhen_SomeNullStreams() external {
+    function test_RevertWhen_SomeNullStreams() external arrayCountNotZero {
         uint256 nullStreamId = 1729;
         uint256[] memory streamIds = Solarray.uint256s(defaultStreamIds[0], nullStreamId);
         lockup.cancelMultiple(streamIds);
@@ -45,7 +55,7 @@ abstract contract CancelMultiple_Unit_Test is Unit_Test, Lockup_Shared_Test {
     }
 
     /// @dev it should do nothing.
-    function test_RevertWhen_AllStreamsNonCancelable() external onlyNonNullStreams {
+    function test_RevertWhen_AllStreamsNonCancelable() external arrayCountNotZero onlyNonNullStreams {
         // Create the non-cancelable stream.
         uint256 nonCancelableStreamId = createDefaultStreamNonCancelable();
 
@@ -54,7 +64,7 @@ abstract contract CancelMultiple_Unit_Test is Unit_Test, Lockup_Shared_Test {
     }
 
     /// @dev it should ignore the non-cancelable streams and cancel the cancelable streams.
-    function test_RevertWhen_SomeStreamsNonCancelable() external onlyNonNullStreams {
+    function test_RevertWhen_SomeStreamsNonCancelable() external arrayCountNotZero onlyNonNullStreams {
         // Create the non-cancelable stream.
         uint256 nonCancelableStreamId = createDefaultStreamNonCancelable();
 
@@ -78,6 +88,7 @@ abstract contract CancelMultiple_Unit_Test is Unit_Test, Lockup_Shared_Test {
     /// @dev it should revert.
     function test_RevertWhen_CallerUnauthorizedAllStreams_MaliciousThirdParty()
         external
+        arrayCountNotZero
         onlyNonNullStreams
         allStreamsCancelable
     {
@@ -94,6 +105,7 @@ abstract contract CancelMultiple_Unit_Test is Unit_Test, Lockup_Shared_Test {
     /// @dev it should revert.
     function test_RevertWhen_CallerUnauthorizedAllStreams_ApprovedOperator()
         external
+        arrayCountNotZero
         onlyNonNullStreams
         allStreamsCancelable
     {
@@ -113,6 +125,7 @@ abstract contract CancelMultiple_Unit_Test is Unit_Test, Lockup_Shared_Test {
     /// @dev it should revert.
     function test_RevertWhen_CallerUnauthorizedAllStreams_FormerRecipient()
         external
+        arrayCountNotZero
         onlyNonNullStreams
         allStreamsCancelable
     {
@@ -130,6 +143,7 @@ abstract contract CancelMultiple_Unit_Test is Unit_Test, Lockup_Shared_Test {
     /// @dev it should revert.
     function test_RevertWhen_CallerUnauthorizedSomeStreams_MaliciousThirdParty()
         external
+        arrayCountNotZero
         onlyNonNullStreams
         allStreamsCancelable
     {
@@ -149,6 +163,7 @@ abstract contract CancelMultiple_Unit_Test is Unit_Test, Lockup_Shared_Test {
     /// @dev it should revert.
     function test_RevertWhen_CallerUnauthorizedSomeStreams_ApprovedOperator()
         external
+        arrayCountNotZero
         onlyNonNullStreams
         allStreamsCancelable
     {
@@ -168,6 +183,7 @@ abstract contract CancelMultiple_Unit_Test is Unit_Test, Lockup_Shared_Test {
     /// @dev it should revert.
     function test_RevertWhen_CallerUnauthorizedSomeStreams_FormerRecipient()
         external
+        arrayCountNotZero
         onlyNonNullStreams
         allStreamsCancelable
     {
@@ -187,7 +203,13 @@ abstract contract CancelMultiple_Unit_Test is Unit_Test, Lockup_Shared_Test {
 
     /// @dev it should perform the ERC-20 transfers, cancel the streams, update the withdrawn amounts, and emit
     /// CancelLockupStream events.
-    function test_CancelMultiple_Sender() external onlyNonNullStreams allStreamsCancelable callerAuthorizedAllStreams {
+    function test_CancelMultiple_Sender()
+        external
+        arrayCountNotZero
+        onlyNonNullStreams
+        allStreamsCancelable
+        callerAuthorizedAllStreams
+    {
         changePrank({ msgSender: users.sender });
         test_CancelMultiple();
     }

test/unit/lockup/shared/cancel-multiple/cancelMultiple.tree

@@ -1,30 +1,33 @@
 cancelMultiple.t.sol
-├── when the stream ids array points only to null streams
+├── when the array count is zero
 │  └── it should do nothing
-├── when the stream ids array points to some null streams
-│  └── it should ignore the null streams and cancel the non-null ones
-└── when the stream ids array points only to non-null streams
-   ├── when all streams are non-cancelable
+└── when the array count is not zero
+   ├── when the stream ids array points only to null streams
    │  └── it should do nothing
-   ├── when some of the streams are non-cancelable
-   │  └── it should ignore the non-cancelable streams and cancel the cancelable streams
-   └── when all streams are cancelable
-      ├── when the caller is unauthorized for any stream
-      │  ├── when the caller is a malicious third-party
-      │  │  └── it should revert
-      │  ├── when the caller is an approved operator
-      │  │  └── it should revert
-      │  └── when the caller is a former recipient
-      │     └── it should revert
-      ├── when the caller is unauthorized for some streams
-      │  ├── when the caller is a malicious third-party
-      │  │  └── it should revert
-      │  ├── when the caller is an approved operator
-      │  │  └── it should revert
-      │  └── when the caller is a former recipient
-      │     └── it should revert
-      └── when the caller is authorized for all streams
-         ├── when the caller is the sender
-         │  └── it should perform the ERC-20 transfers, cancel the streams, update the withdrawn amounts, and emit {CancelLockupStream} events
-         └── when the caller is the recipient
-            └── it should perform the ERC-20 transfers, cancel the streams, update the withdrawn amounts, and emit {CancelLockupStream} events
+   ├── when the stream ids array points to some null streams
+   │  └── it should ignore the null streams and cancel the non-null ones
+   └── when the stream ids array points only to non-null streams
+      ├── when all streams are non-cancelable
+      │  └── it should do nothing
+      ├── when some of the streams are non-cancelable
+      │  └── it should ignore the non-cancelable streams and cancel the cancelable streams
+      └── when all streams are cancelable
+         ├── when the caller is unauthorized for any stream
+         │  ├── when the caller is a malicious third-party
+         │  │  └── it should revert
+         │  ├── when the caller is an approved operator
+         │  │  └── it should revert
+         │  └── when the caller is a former recipient
+         │     └── it should revert
+         ├── when the caller is unauthorized for some streams
+         │  ├── when the caller is a malicious third-party
+         │  │  └── it should revert
+         │  ├── when the caller is an approved operator
+         │  │  └── it should revert
+         │  └── when the caller is a former recipient
+         │     └── it should revert
+         └── when the caller is authorized for all streams
+            ├── when the caller is the sender
+            │  └── it should perform the ERC-20 transfers, cancel the streams, update the withdrawn amounts, and emit {CancelLockupStream} events
+            └── when the caller is the recipient
+               └── it should perform the ERC-20 transfers, cancel the streams, update the withdrawn amounts, and emit {CancelLockupStream} events