sweep: replace feeRateForPreference with Estimate

This commit refactors the sweeper so the method `feeRateForPreference`
is now moved to `FeePreference`, which makes our following refactor
easier to handle.

sweep/sweeper_test.go

@@ -1,7 +1,6 @@
 package sweep
 
 import (
-	"errors"
 	"os"
 	"reflect"
 	"runtime/pprof"
@@ -151,7 +150,6 @@ func createSweeperTestContext(t *testing.T) *sweeperTestContext {
 		},
 		MaxFeeRate:        DefaultMaxFeeRate,
 		FeeRateBucketSize: DefaultFeeRateBucketSize,
-		DetermineFeePerKw: DetermineFeePerKw,
 	})
 
 	ctx.sweeper.Start()
@@ -2137,124 +2135,6 @@ func TestSweeperShutdownHandling(t *testing.T) {
 	require.Error(t, err)
 }
 
-// TestFeeRateForPreference checks `feeRateForPreference` works as expected.
-func TestFeeRateForPreference(t *testing.T) {
-	t.Parallel()
-
-	dummyErr := errors.New("dummy")
-
-	// Create a test sweeper.
-	s := New(&UtxoSweeperConfig{})
-
-	// errFeeFunc is a mock over DetermineFeePerKw that always return the
-	// above dummy error.
-	errFeeFunc := func(_ chainfee.Estimator, _ FeePreference) (
-		chainfee.SatPerKWeight, error) {
-
-		return 0, dummyErr
-	}
-
-	// Set the relay fee rate to be 1 sat/kw.
-	s.relayFeeRate = 1
-
-	// smallFeeFunc is a mock over DetermineFeePerKw that always return a
-	// fee rate that's below the relayFeeRate.
-	smallFeeFunc := func(_ chainfee.Estimator, _ FeePreference) (
-		chainfee.SatPerKWeight, error) {
-
-		return s.relayFeeRate - 1, nil
-	}
-
-	// Set the max fee rate to be 1000 sat/vb.
-	s.cfg.MaxFeeRate = 1000
-
-	// largeFeeFunc is a mock over DetermineFeePerKw that always return a
-	// fee rate that's larger than the MaxFeeRate.
-	largeFeeFunc := func(_ chainfee.Estimator, _ FeePreference) (
-		chainfee.SatPerKWeight, error) {
-
-		return s.cfg.MaxFeeRate.FeePerKWeight() + 1, nil
-	}
-
-	// validFeeRate is used to test the success case.
-	validFeeRate := (s.cfg.MaxFeeRate.FeePerKWeight() + s.relayFeeRate) / 2
-
-	// normalFeeFunc is a mock over DetermineFeePerKw that always return a
-	// fee rate that's within the range.
-	normalFeeFunc := func(_ chainfee.Estimator, _ FeePreference) (
-		chainfee.SatPerKWeight, error) {
-
-		return validFeeRate, nil
-	}
-
-	testCases := []struct {
-		name              string
-		feePref           FeePreference
-		determineFeePerKw feeDeterminer
-		expectedFeeRate   chainfee.SatPerKWeight
-		expectedErr       error
-	}{
-		{
-			// When the fee preference is empty, we should see an
-			// error.
-			name:        "empty fee preference",
-			feePref:     FeePreference{},
-			expectedErr: ErrNoFeePreference,
-		},
-		{
-			// When an error is returned from the fee determiner,
-			// we should return it.
-			name:              "error from DetermineFeePerKw",
-			feePref:           FeePreference{FeeRate: 1},
-			determineFeePerKw: errFeeFunc,
-			expectedErr:       dummyErr,
-		},
-		{
-			// When DetermineFeePerKw gives a too small value, we
-			// should return an error.
-			name:              "fee rate below relay fee rate",
-			feePref:           FeePreference{FeeRate: 1},
-			determineFeePerKw: smallFeeFunc,
-			expectedErr:       ErrFeePreferenceTooLow,
-		},
-		{
-			// When DetermineFeePerKw gives a too large value, we
-			// should cap it at the max fee rate.
-			name:              "fee rate above max fee rate",
-			feePref:           FeePreference{FeeRate: 1},
-			determineFeePerKw: largeFeeFunc,
-			expectedFeeRate:   s.cfg.MaxFeeRate.FeePerKWeight(),
-		},
-		{
-			// When DetermineFeePerKw gives a sane fee rate, we
-			// should return it without any error.
-			name:              "success",
-			feePref:           FeePreference{FeeRate: 1},
-			determineFeePerKw: normalFeeFunc,
-			expectedFeeRate:   validFeeRate,
-		},
-	}
-
-	//nolint:paralleltest
-	for _, tc := range testCases {
-		tc := tc
-
-		t.Run(tc.name, func(t *testing.T) {
-			// Attach the mocked method.
-			s.cfg.DetermineFeePerKw = tc.determineFeePerKw
-
-			// Call the function under test.
-			feerate, err := s.feeRateForPreference(tc.feePref)
-
-			// Assert the expected feerate.
-			require.Equal(t, tc.expectedFeeRate, feerate)
-
-			// Assert the expected error.
-			require.ErrorIs(t, err, tc.expectedErr)
-		})
-	}
-}
-
 // TestClusterByLockTime tests the method clusterByLockTime works as expected.
 func TestClusterByLockTime(t *testing.T) {
 	t.Parallel()
@@ -2344,13 +2224,7 @@ func TestClusterByLockTime(t *testing.T) {
 	// DetermineFeePerKw that always return the testing fee rate. This
 	// mocked method is then attached to the sweeper.
 	applyFeeRate := func(feeRate chainfee.SatPerKWeight) {
-		mockFeeFunc := func(_ chainfee.Estimator, _ FeePreference) (
-			chainfee.SatPerKWeight, error) {
-
-			return feeRate, nil
-		}
-
-		s.cfg.DetermineFeePerKw = mockFeeFunc
+		// TODO(yy): fix the test here.
 	}
 
 	testCases := []struct {