Implement withdraw flow tests and fixes (#198)

Align Soroban stream withdraw and cancellation behavior with time-based accrual semantics, fixing test helpers around initialization, top-ups, and withdraw events.

Made-with: Cursor

Author: JamesVictor-O

contracts/stream_contract/src/test.rs

@@ -112,10 +112,6 @@ fn test_initialize_rejects_second_call() {
     let admin = Address::generate(&env);
     let treasury = Address::generate(&env);
 
-    assert_eq!(stream_id1, 1);
-    assert_eq!(stream_id2, 2);
-    assert!(client.get_stream(&stream_id1).is_some());
-    assert!(client.get_stream(&stream_id2).is_some());
     client.initialize(&admin, &treasury, &100);
     let result = client.try_initialize(&admin, &treasury, &100);
     assert_eq!(result, Err(Ok(StreamError::AlreadyInitialized)));
@@ -344,10 +340,6 @@ fn test_top_up_rejects_negative_amount() {
     let client = create_contract(&env);
     let id = client.create_stream(&sender, &Address::generate(&env), &token, &10_000, &100);
 
-    let contract_id = env.register(StreamContract, ());
-    let client = StreamContractClient::new(&env, &contract_id);
-    let token_client = token::Client::new(&env, &token_address);
-    token_client.approve(&sender, &contract_id, &20_000, &1_000_000);
     assert_eq!(
         client.try_top_up_stream(&sender, &id, &-50),
         Err(Ok(StreamError::InvalidAmount))
@@ -522,10 +514,6 @@ fn test_withdraw_emits_event() {
     let client = create_contract(&env);
     let id = client.create_stream(&sender, &recipient, &token, &500, &100);
 
-    let contract_id = env.register(StreamContract, ());
-    let client = StreamContractClient::new(&env, &contract_id);
-    let token_client = token::Client::new(&env, &token_address);
-    token_client.approve(&sender, &contract_id, &20_000, &1_000_000);
     // Advance time by 100 seconds to allow full withdrawal (500 tokens / 100 seconds = 5 tokens/sec)
     env.ledger().with_mut(|l| {
         l.timestamp += 100;

contracts/stream_contract/test_snapshots/test/test_cancel_stream_after_partial_withdrawal.1.json

@@ -154,6 +154,7 @@
       ]
     ],
     [],
+    [],
     []
   ],
   "ledger": {
@@ -473,7 +474,7 @@
                       "val": {
                         "i128": {
                           "hi": 0,
-                          "lo": 200
+                          "lo": 300
                         }
                       }
                     }
@@ -648,7 +649,7 @@
                       "val": {
                         "i128": {
                           "hi": 0,
-                          "lo": 200
+                          "lo": 300
                         }
                       }
                     },
@@ -721,7 +722,7 @@
                       "val": {
                         "i128": {
                           "hi": 0,
-                          "lo": 100
+                          "lo": 0
                         }
                       }
                     },

contracts/stream_contract/test_snapshots/test/test_cancel_stream_refunds_sender.1.json

@@ -132,6 +132,7 @@
     ],
     [],
     [],
+    [],
     []
   ],
   "ledger": {
@@ -418,7 +419,7 @@
                       "val": {
                         "i128": {
                           "hi": 0,
-                          "lo": 0
+                          "lo": 300
                         }
                       }
                     }
@@ -549,6 +550,79 @@
           518400
         ]
       ],
+      [
+        {
+          "contract_data": {
+            "contract": "CBEPDNVYXQGWB5YUBXKJWYJA7OXTZW5LFLNO5JRRGE6Z6C5OSUZPCCEL",
+            "key": {
+              "vec": [
+                {
+                  "symbol": "Balance"
+                },
+                {
+                  "address": "CAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAITA4"
+                }
+              ]
+            },
+            "durability": "persistent"
+          }
+        },
+        [
+          {
+            "last_modified_ledger_seq": 0,
+            "data": {
+              "contract_data": {
+                "ext": "v0",
+                "contract": "CBEPDNVYXQGWB5YUBXKJWYJA7OXTZW5LFLNO5JRRGE6Z6C5OSUZPCCEL",
+                "key": {
+                  "vec": [
+                    {
+                      "symbol": "Balance"
+                    },
+                    {
+                      "address": "CAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAITA4"
+                    }
+                  ]
+                },
+                "durability": "persistent",
+                "val": {
+                  "map": [
+                    {
+                      "key": {
+                        "symbol": "amount"
+                      },
+                      "val": {
+                        "i128": {
+                          "hi": 0,
+                          "lo": 300
+                        }
+                      }
+                    },
+                    {
+                      "key": {
+                        "symbol": "authorized"
+                      },
+                      "val": {
+                        "bool": true
+                      }
+                    },
+                    {
+                      "key": {
+                        "symbol": "clawback"
+                      },
+                      "val": {
+                        "bool": false
+                      }
+                    }
+                  ]
+                }
+              }
+            },
+            "ext": "v0"
+          },
+          518400
+        ]
+      ],
       [
         {
           "contract_data": {
@@ -593,7 +667,7 @@
                       "val": {
                         "i128": {
                           "hi": 0,
-                          "lo": 300
+                          "lo": 0
                         }
                       }
                     },