add query for accepted policy

elections/README.md

@@ -44,6 +44,9 @@ near view $CTR proposals '{"prop_id": 2}'
 # accept fair voting policy
 near call $CTR accept_fair_voting_policy '{"policy": "f1c09f8686fe7d0d798517111a66675da0012d8ad1693a47e0e2a7d3ae1c69d4"}' --deposit 0.001 --accountId me.testnet
 
+# query the accepted policy by user it either returns the policy or `None` if user did not accept any policy
+near call $CTR accepted_policy '{"user": "alice.testnet"}' --accountId me.testnet
+
 # vote
 near call $CTR vote '{"prop_id": 1, "vote": ["candidate1.testnet", "candidate3.testnet"]}' --gas 70000000000000 --deposit 0.0005 --accountId me.testnet
 ```

elections/src/lib.rs

@@ -152,6 +152,15 @@ impl Contract {
             )
     }
 
+    /*****************
+     * QUERIES
+     ****************/
+
+    /// Returns the policy if user has accepted it otherwise returns None
+    pub fn accepted_policy(&self, user: AccountId) -> Option<[u8; 32]> {
+        self.accepted_policy.get(&user)
+    }
+
     /*****************
      * PRIVATE
      ****************/
@@ -194,6 +203,7 @@ impl Contract {
 #[cfg(all(test, not(target_arch = "wasm32")))]
 mod unit_tests {
     use near_sdk::{test_utils::VMContextBuilder, testing_env, Gas, VMContext};
+    use uint::hex;
 
     use crate::*;
 
@@ -574,6 +584,23 @@ mod unit_tests {
         ctr.vote(prop_id, vec![candidate(1)]);
     }
 
+    #[test]
+    fn accepted_policy_query() {
+        let (mut ctx, mut ctr) = setup(&admin());
+
+        let mut res = ctr.accepted_policy(admin());
+        assert!(res.is_none());
+        ctx.attached_deposit = ACCEPT_POLICY_COST;
+        testing_env!(ctx.clone());
+        ctr.accept_fair_voting_policy(policy1());
+        res = ctr.accepted_policy(admin());
+        assert!(res.is_some());
+        let mut expected: [u8; 32] = [0u8; 32];
+        let res1 = hex::decode_to_slice(policy1(), &mut expected);
+        assert!(res1.is_ok());
+        assert_eq!(res.unwrap(), expected);
+    }
+
     #[test]
     #[should_panic(expected = "double vote for the same candidate")]
     fn vote_double_vote_same_candidate() {