Implement client functionality for the community pool (cosmos#3939)

Fixes: cosmos#3937

.pending/features/gaiacli/3937-Add-command-to-query-community-pool

@@ -0,0 +1 @@
+#3937 Add command to query community-pool

.pending/features/gaiarest/3937-Add-route-to-fetch-community-pool

@@ -0,0 +1 @@
+#3937 Add route to fetch community-pool

.pending/improvements/sdk/3937-Implement-community-pool-querier

@@ -0,0 +1 @@
+#3937 Implement community pool querier.

client/lcd/swagger-ui/swagger.yaml

@@ -1632,6 +1632,22 @@ paths:
           description: Key password is wrong
         500:
           description: Internal Server Error
+  /distribution/community_pool:
+    get:
+      summary: Community pool parameters
+      tags:
+        - ICS24
+      produces:
+        - application/json
+      responses:
+        200:
+          description: OK
+          schema:
+            type: array
+            items:
+              $ref: "#/definitions/Coin"
+        500:
+          description: Internal Server Error
   /distribution/parameters:
     get:
       summary: Fee distribution parameters

docs/gaia/gaiacli.md

@@ -637,6 +637,14 @@ To check the current distribution parameters, run:
 gaiacli query distr params
 ```
 
+#### Query distribution Community Pool
+
+To query all coins in the community pool which is under Governance control:
+
+```bash
+gaiacli query distr community-pool
+```
+
 #### Query outstanding rewards
 
 To check the current outstanding (un-withdrawn) rewards, run:

x/distribution/client/cli/query.go

@@ -163,3 +163,28 @@ $ gaiacli query distr rewards cosmos1gghjut3ccd8ay0zduzj64hwre2fxs9ld75ru9p cosm
 		},
 	}
 }
+
+// GetCmdQueryCommunityPool returns the command for fetching community pool info
+func GetCmdQueryCommunityPool(queryRoute string, cdc *codec.Codec) *cobra.Command {
+	return &cobra.Command{
+		Use:   "community-pool",
+		Args:  cobra.NoArgs,
+		Short: "Query the amount of coins in the community pool",
+		Long: strings.TrimSpace(`Query all coins in the community pool which is under Governance control.
+
+$ gaiacli query distr community-pool
+`),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			cliCtx := context.NewCLIContext().WithCodec(cdc)
+
+			res, err := cliCtx.QueryWithData(fmt.Sprintf("custom/%s/community_pool", queryRoute), nil)
+			if err != nil {
+				return err
+			}
+
+			var result sdk.DecCoins
+			cdc.MustUnmarshalJSON(res, &result)
+			return cliCtx.PrintOutput(result)
+		},
+	}
+}

x/distribution/client/module_client.go

@@ -31,6 +31,7 @@ func (mc ModuleClient) GetQueryCmd() *cobra.Command {
 		distCmds.GetCmdQueryValidatorCommission(mc.storeKey, mc.cdc),
 		distCmds.GetCmdQueryValidatorSlashes(mc.storeKey, mc.cdc),
 		distCmds.GetCmdQueryDelegatorRewards(mc.storeKey, mc.cdc),
+		distCmds.GetCmdQueryCommunityPool(mc.storeKey, mc.cdc),
 	)...)
 
 	return distQueryCmd

x/distribution/client/rest/query.go

@@ -61,6 +61,12 @@ func registerQueryRoutes(cliCtx context.CLIContext, r *mux.Router,
 		paramsHandlerFn(cliCtx, cdc, queryRoute),
 	).Methods("GET")
 
+	// Get the amount held in the community pool
+	r.HandleFunc(
+		"/distribution/community_pool",
+		communityPoolHandler(cliCtx, cdc, queryRoute),
+	).Methods("GET")
+
 }
 
 // HTTP request handler to query the total rewards balance from all delegations
@@ -207,6 +213,26 @@ func paramsHandlerFn(cliCtx context.CLIContext, cdc *codec.Codec,
 	}
 }
 
+func communityPoolHandler(cliCtx context.CLIContext, cdc *codec.Codec,
+	queryRoute string) http.HandlerFunc {
+
+	return func(w http.ResponseWriter, r *http.Request) {
+		res, err := cliCtx.QueryWithData(fmt.Sprintf("custom/%s/community_pool", queryRoute), nil)
+		if err != nil {
+			rest.WriteErrorResponse(w, http.StatusInternalServerError, err.Error())
+			return
+		}
+
+		var result sdk.DecCoins
+		if err := cdc.UnmarshalJSON(res, &result); err != nil {
+			rest.WriteErrorResponse(w, http.StatusInternalServerError, err.Error())
+			return
+		}
+
+		rest.PostProcessResponse(w, cdc, result, cliCtx.Indent)
+	}
+}
+
 // HTTP request handler to query the outstanding rewards
 func outstandingRewardsHandlerFn(cliCtx context.CLIContext, cdc *codec.Codec,
 	queryRoute string) http.HandlerFunc {

x/distribution/keeper/querier.go

@@ -20,6 +20,7 @@ const (
 	QueryDelegatorTotalRewards       = "delegator_total_rewards"
 	QueryDelegatorValidators         = "delegator_validators"
 	QueryWithdrawAddr                = "withdraw_addr"
+	QueryCommunityPool               = "community_pool"
 
 	ParamCommunityTax        = "community_tax"
 	ParamBaseProposerReward  = "base_proposer_reward"
@@ -54,6 +55,9 @@ func NewQuerier(k Keeper) sdk.Querier {
 		case QueryWithdrawAddr:
 			return queryDelegatorWithdrawAddress(ctx, path[1:], req, k)
 
+		case QueryCommunityPool:
+			return queryCommunityPool(ctx, path[1:], req, k)
+
 		default:
 			return nil, sdk.ErrUnknownRequest("unknown distr query endpoint")
 		}
@@ -314,3 +318,11 @@ func queryDelegatorWithdrawAddress(ctx sdk.Context, _ []string, req abci.Request
 
 	return bz, nil
 }
+
+func queryCommunityPool(ctx sdk.Context, _ []string, req abci.RequestQuery, k Keeper) ([]byte, sdk.Error) {
+	bz, err := k.cdc.MarshalJSON(k.GetFeePoolCommunityCoins(ctx))
+	if err != nil {
+		return nil, sdk.ErrInternal(sdk.AppendMsgToErr("could not marshal result to JSON", err.Error()))
+	}
+	return bz, nil
+}

x/distribution/keeper/querier_test.go

@@ -109,6 +109,19 @@ func getQueriedDelegationRewards(t *testing.T, ctx sdk.Context, cdc *codec.Codec
 	return
 }
 
+func getQueriedCommunityPool(t *testing.T, ctx sdk.Context, cdc *codec.Codec, querier sdk.Querier) (ptr []byte) {
+	query := abci.RequestQuery{
+		Path: strings.Join([]string{custom, types.QuerierRoute, QueryCommunityPool}, ""),
+		Data: []byte{},
+	}
+
+	cp, err := querier(ctx, []string{QueryCommunityPool}, query)
+	require.Nil(t, err)
+	require.Nil(t, cdc.UnmarshalJSON(cp, &ptr))
+
+	return
+}
+
 func TestQueries(t *testing.T) {
 	cdc := codec.New()
 	ctx, _, keeper, sk, _ := CreateTestInputDefault(t, false, 100)
@@ -169,4 +182,8 @@ func TestQueries(t *testing.T) {
 	keeper.AllocateTokensToValidator(ctx, val, tokens)
 	rewards = getQueriedDelegationRewards(t, ctx, cdc, querier, sdk.AccAddress(valOpAddr1), valOpAddr1)
 	require.Equal(t, sdk.DecCoins{{sdk.DefaultBondDenom, sdk.NewDec(initial / 2)}}, rewards)
+
+	// currently community pool hold nothing so we should return null
+	communityPool := getQueriedCommunityPool(t, ctx, cdc, querier)
+	require.Nil(t, communityPool)
 }