From 172db751a5597afe4f22316fdf24721a0b84f1c4 Mon Sep 17 00:00:00 2001
From: davidbrai <davidbrai@gmail.com>
Date: Mon, 2 Dec 2024 09:40:15 +0000
Subject: [PATCH 1/3] add unstreamedETHForNoun

---
 .../contracts/StreamEscrow.sol                | 11 +++++
 .../test/foundry/StreamEscrow.t.sol           | 48 +++++++++++++++++++
 2 files changed, 59 insertions(+)

diff --git a/packages/nouns-contracts/contracts/StreamEscrow.sol b/packages/nouns-contracts/contracts/StreamEscrow.sol
index 5acd8a077..10048abd9 100644
--- a/packages/nouns-contracts/contracts/StreamEscrow.sol
+++ b/packages/nouns-contracts/contracts/StreamEscrow.sol
@@ -245,6 +245,17 @@ contract StreamEscrow is IStreamEscrow {
         return !streams[nounId].canceled && streams[nounId].lastTick > currentTick;
     }
 
+    function unstreamedETHForNoun(uint256 nounId) public view returns (uint256) {
+        Stream memory stream = streams[nounId];
+        uint32 currentTick_ = currentTick;
+        if (!isStreamActive(stream, currentTick_)) {
+            return 0;
+        }
+
+        uint256 ticksLeft = stream.lastTick - currentTick_;
+        return ticksLeft * stream.ethPerTick;
+    }
+
     function isStreamActive(Stream memory stream, uint32 tick) internal pure returns (bool) {
         return !stream.canceled && stream.lastTick > tick;
     }
diff --git a/packages/nouns-contracts/test/foundry/StreamEscrow.t.sol b/packages/nouns-contracts/test/foundry/StreamEscrow.t.sol
index 99d7e1666..4ea363ced 100644
--- a/packages/nouns-contracts/test/foundry/StreamEscrow.t.sol
+++ b/packages/nouns-contracts/test/foundry/StreamEscrow.t.sol
@@ -717,6 +717,54 @@ contract RescueTokensTest is BaseStreamEscrowTest {
     }
 }
 
+contract UnstreamedETHTest is BaseStreamEscrowTest {
+    function test_unstreamedETHForNoun() public {
+        vm.prank(streamCreator);
+        escrow.forwardAllAndCreateStream{ value: 1 ether }({ nounId: 1, streamLengthInTicks: 20 });
+
+        // 1 ether / 20 = 0.05 eth per tick
+        assertEq(escrow.unstreamedETHForNoun(1), 1 ether);
+
+        // forward 5 ticks
+        for (uint i; i < 5; i++) {
+            forwardOneDay();
+        }
+        // check unstreamed eth
+        assertEq(escrow.unstreamedETHForNoun(1), 0.75 ether);
+
+        // forward 15 more ticks
+        for (uint i; i < 15; i++) {
+            forwardOneDay();
+        }
+        // check unstreamed eth
+        assertEq(escrow.unstreamedETHForNoun(1), 0 ether);
+    }
+
+    function test_unstreamETHForNoun_canceledStream() public {
+        vm.prank(streamCreator);
+        escrow.forwardAllAndCreateStream{ value: 1 ether }({ nounId: 1, streamLengthInTicks: 20 });
+
+        // 1 ether / 20 = 0.05 eth per tick
+        assertEq(escrow.unstreamedETHForNoun(1), 1 ether);
+
+        // forward 5 ticks
+        for (uint i; i < 5; i++) {
+            forwardOneDay();
+        }
+        // check unstreamed eth
+        assertEq(escrow.unstreamedETHForNoun(1), 0.75 ether);
+
+        // cancel stream
+        vm.prank(streamCreator);
+        nounsToken.approve(address(escrow), 1);
+        vm.prank(streamCreator);
+        escrow.cancelStream(1);
+
+        // check unstreamed eth is zero
+        assertEq(escrow.unstreamedETHForNoun(1), 0 ether);
+    }
+}
+
 contract StreamEscrowGasTest is BaseStreamEscrowTest {
     function setUp() public virtual override {
         super.setUp();

From f1c4fdf7e696c1fc99b0da0546d4e34f47011179 Mon Sep 17 00:00:00 2001
From: davidbrai <davidbrai@gmail.com>
Date: Mon, 2 Dec 2024 09:43:05 +0000
Subject: [PATCH 2/3] add test

---
 .../nouns-contracts/test/foundry/StreamEscrow.t.sol | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/packages/nouns-contracts/test/foundry/StreamEscrow.t.sol b/packages/nouns-contracts/test/foundry/StreamEscrow.t.sol
index 4ea363ced..1bc3e8d00 100644
--- a/packages/nouns-contracts/test/foundry/StreamEscrow.t.sol
+++ b/packages/nouns-contracts/test/foundry/StreamEscrow.t.sol
@@ -740,7 +740,7 @@ contract UnstreamedETHTest is BaseStreamEscrowTest {
         assertEq(escrow.unstreamedETHForNoun(1), 0 ether);
     }
 
-    function test_unstreamETHForNoun_canceledStream() public {
+    function test_unstreamedETHForNoun_canceledStream() public {
         vm.prank(streamCreator);
         escrow.forwardAllAndCreateStream{ value: 1 ether }({ nounId: 1, streamLengthInTicks: 20 });
 
@@ -763,6 +763,17 @@ contract UnstreamedETHTest is BaseStreamEscrowTest {
         // check unstreamed eth is zero
         assertEq(escrow.unstreamedETHForNoun(1), 0 ether);
     }
+
+    function test_unstreamedETHForNoun_returnsZeroForNonExistentStream() public {
+        assertEq(escrow.unstreamedETHForNoun(1), 0 ether);
+
+        // forward 5 ticks
+        for (uint i; i < 5; i++) {
+            forwardOneDay();
+        }
+
+        assertEq(escrow.unstreamedETHForNoun(3), 0 ether);
+    }
 }
 
 contract StreamEscrowGasTest is BaseStreamEscrowTest {

From 8888e0d9e3c0a5e8bca797829f73d699e795f34e Mon Sep 17 00:00:00 2001
From: davidbrai <davidbrai@gmail.com>
Date: Tue, 3 Dec 2024 11:53:55 +0000
Subject: [PATCH 3/3] add natspec

---
 packages/nouns-contracts/contracts/StreamEscrow.sol | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/packages/nouns-contracts/contracts/StreamEscrow.sol b/packages/nouns-contracts/contracts/StreamEscrow.sol
index 10048abd9..d174841d2 100644
--- a/packages/nouns-contracts/contracts/StreamEscrow.sol
+++ b/packages/nouns-contracts/contracts/StreamEscrow.sol
@@ -245,6 +245,11 @@ contract StreamEscrow is IStreamEscrow {
         return !streams[nounId].canceled && streams[nounId].lastTick > currentTick;
     }
 
+    /**
+     * @notice Returns the amount of ETH that was not yet streamed for a specific Noun token.
+     * Returns zero for inactive streams.
+     * @param nounId The ID of the Noun token to check the stream for.
+     */
     function unstreamedETHForNoun(uint256 nounId) public view returns (uint256) {
         Stream memory stream = streams[nounId];
         uint32 currentTick_ = currentTick;