feat: add the gas estimation API to the signer (#4270)

## Overview

Closes #4258

If there are other places where it would be beneficial to document the
API, please let me know to make the corresponding changes.

(cherry picked from commit eb9f3c2)

pkg/user/signer.go

@@ -1,15 +1,18 @@
 package user
 
 import (
+	"context"
 	"errors"
 	"fmt"
 
+	"github.com/celestiaorg/celestia-app/v3/app/grpc/gasestimation"
 	"github.com/cosmos/cosmos-sdk/client"
 	"github.com/cosmos/cosmos-sdk/crypto/keyring"
 	cryptotypes "github.com/cosmos/cosmos-sdk/crypto/types"
 	sdktypes "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/tx/signing"
 	authsigning "github.com/cosmos/cosmos-sdk/x/auth/signing"
+	"google.golang.org/grpc"
 
 	blobtypes "github.com/celestiaorg/celestia-app/v3/x/blob/types"
 	"github.com/celestiaorg/go-square/v2/share"
@@ -298,3 +301,46 @@ func (s *Signer) getSignatureV2(sequence uint64, pubKey cryptotypes.PubKey, sign
 	}
 	return sigV2
 }
+
+// QueryGasPrice takes a priority and an app gRPC client.
+// Returns the current network gas price corresponding to the provided priority.
+// More on the gas price estimation can be found in docs/architecture/adr-023-gas-used-and-gas-price-estimation.md
+func (s *Signer) QueryGasPrice(
+	ctx context.Context,
+	grpcClient *grpc.ClientConn,
+	priority gasestimation.TxPriority,
+) (float64, error) {
+	estimator := gasestimation.NewGasEstimatorClient(grpcClient)
+	gasPrice, err := estimator.EstimateGasPrice(
+		ctx,
+		&gasestimation.EstimateGasPriceRequest{TxPriority: priority},
+	)
+	if err != nil {
+		return 0, err
+	}
+	return gasPrice.EstimatedGasPrice, nil
+}
+
+// QueryGasUsedAndPrice takes a priority, an app gRPC client, and a transaction bytes.
+// Returns the current network gas price corresponding to the provided priority,
+// and the gas used estimation for the provided transaction bytes.
+// More on the gas estimation can be found in docs/architecture/adr-023-gas-used-and-gas-price-estimation.md
+func (s *Signer) QueryGasUsedAndPrice(
+	ctx context.Context,
+	grpcClient *grpc.ClientConn,
+	priority gasestimation.TxPriority,
+	txBytes []byte,
+) (float64, uint64, error) {
+	estimator := gasestimation.NewGasEstimatorClient(grpcClient)
+	gasEstimation, err := estimator.EstimateGasPriceAndUsage(
+		ctx,
+		&gasestimation.EstimateGasPriceAndUsageRequest{
+			TxPriority: priority,
+			TxBytes:    txBytes,
+		},
+	)
+	if err != nil {
+		return 0, 0, err
+	}
+	return gasEstimation.EstimatedGasPrice, gasEstimation.EstimatedGasUsed, nil
+}

pkg/user/tx_client_test.go

@@ -5,6 +5,9 @@ import (
 	"testing"
 	"time"
 
+	"github.com/celestiaorg/celestia-app/v3/app/grpc/gasestimation"
+	"github.com/stretchr/testify/assert"
+
 	"github.com/celestiaorg/celestia-app/v3/app"
 	"github.com/celestiaorg/celestia-app/v3/app/encoding"
 	"github.com/celestiaorg/celestia-app/v3/pkg/appconsts"
@@ -350,3 +353,29 @@ func setupTxClient(t *testing.T, ttlDuration time.Duration) (encoding.Config, *u
 	require.NoError(t, err)
 	return encCfg, txClient, ctx
 }
+
+func (suite *TxClientTestSuite) TestGasPriceAndUsedEstimate() {
+	t := suite.T()
+	ctx := context.Background()
+	signer := suite.txClient.Signer()
+
+	t.Run("query the gas price from the app gRPC", func(t *testing.T) {
+		gasPrice, err := signer.QueryGasPrice(ctx, suite.ctx.GRPCClient, gasestimation.TxPriority_TX_PRIORITY_HIGH)
+		assert.NoError(t, err)
+		assert.Greater(t, gasPrice, float64(0))
+	})
+
+	t.Run("query the gas price and gas used from the app gRPC", func(t *testing.T) {
+		msg := bank.NewMsgSend(
+			suite.txClient.DefaultAddress(),
+			testnode.RandomAddress().(sdk.AccAddress),
+			sdk.NewCoins(sdk.NewInt64Coin(appconsts.BondDenom, 10)),
+		)
+		rawTx, err := signer.CreateTx([]sdk.Msg{msg})
+		require.NoError(t, err)
+		gasPrice, gasUsed, err := signer.QueryGasUsedAndPrice(ctx, suite.ctx.GRPCClient, gasestimation.TxPriority_TX_PRIORITY_HIGH, rawTx)
+		assert.NoError(t, err)
+		assert.Greater(t, gasPrice, float64(0))
+		assert.Greater(t, gasUsed, uint64(0))
+	})
+}