GH-749: Update logic for contract existence tests (#384)

Author: utkarshg6

node/tests/contract_test.rs

@@ -14,9 +14,7 @@ fn assert_contract_existence(
     chain: &Chain,
     expected_token_name: &str,
     expected_decimals: u32,
-) -> Result<(), ()> {
-    eprintln!("Starting a new attempt with: '{}'", blockchain_service_url);
-
+) -> Result<(), String> {
     let min_abi_json = r#"[{
         "constant": true,
         "inputs": [],
@@ -54,8 +52,7 @@ fn assert_contract_existence(
     {
         Ok(tn) => tn,
         Err(e) => {
-            eprintln!("Token name query failed due to: {:?}", e);
-            return Err(());
+            return Err(format!("Token name query failed due to: {:?}", e));
         }
     };
     let decimals: u32 = match contract
@@ -64,8 +61,7 @@ fn assert_contract_existence(
     {
         Ok(dec) => dec,
         Err(e) => {
-            eprintln!("Decimals query failed due to: {:?}", e);
-            return Err(());
+            return Err(format!("Decimals query failed due to: {:?}", e));
         }
     };
 
@@ -90,18 +86,22 @@ fn create_contract_interface(transport: Http, chain: &Chain, min_abi_json: &str)
 
 fn assert_contract<'a, F>(blockchain_urls: Vec<&'static str>, chain: &'a Chain, test_performer: F)
 where
-    F: FnOnce(&'static str, &'a Chain) -> Result<(), ()> + Copy,
+    F: FnOnce(&'static str, &'a Chain) -> Result<(), String> + Copy,
 {
-    if !blockchain_urls
-        .iter()
-        .fold(false, |acc, url| match (acc, test_performer(url, chain)) {
-            (true, _) => true,
-            (false, Ok(_)) => true,
-            (false, Err(_)) => false,
-        })
-    {
-        panic!("Test failed on all blockchain services")
+    for blockchain_url in blockchain_urls {
+        eprintln!("Starting a new attempt with: '{}'", blockchain_url);
+        match test_performer(blockchain_url, chain) {
+            Ok(()) => {
+                eprintln!("Attempt Successful!");
+                return;
+            }
+            Err(e) => {
+                eprintln!("Attempt Failed: {:?}", e);
+            }
+        }
     }
+
+    panic!("Test failed on all blockchain services");
 }
 
 #[test]
@@ -144,7 +144,7 @@ fn assert_total_supply(
     blockchain_service_url: &str,
     chain: &Chain,
     expected_total_supply: u64,
-) -> Result<(), ()> {
+) -> Result<(), String> {
     let min_abi_json = r#"[{
        "constant": true,
        "inputs": [],
@@ -169,8 +169,7 @@ fn assert_total_supply(
     {
         Ok(ts) => ts,
         Err(e) => {
-            eprintln!("Total supply query failed due to: {:?}", e);
-            return Err(());
+            return Err(format!("Total supply query failed due to: {:?}", e));
         }
     };
     assert_eq!(