liquidity/test: pass full parameters into suggest swaps and add default

As we add more parameters in this PR, we wil want to test values
beyond our default values. This commit updates the suggest swaps test
helper to take a full setup struct, and adds a default set of channels
and rules which will be used in the absense of this setup struct.

liquidity/liquidity_test.go

@@ -351,13 +351,16 @@ func TestRestrictedSuggestions(t *testing.T) {
 				return testCase.loopIn, nil
 			}
 
-			rules := map[lnwire.ShortChannelID]*ThresholdRule{
+			lnd.Channels = testCase.channels
+
+			params := defaultParameters
+			params.ChannelRules = map[lnwire.ShortChannelID]*ThresholdRule{
 				chanID1: chanRule,
 				chanID2: chanRule,
 			}
 
 			testSuggestSwaps(
-				t, cfg, lnd, testCase.channels, rules,
+				t, newSuggestSwapsSetup(cfg, lnd, params),
 				testCase.expected,
 			)
 		})
@@ -397,16 +400,18 @@ func TestSweepFeeLimit(t *testing.T) {
 				loop.DefaultSweepConfTarget, testCase.feeRate,
 			)
 
-			channels := []lndclient.ChannelInfo{
+			lnd.Channels = []lndclient.ChannelInfo{
 				channel1,
 			}
 
-			rules := map[lnwire.ShortChannelID]*ThresholdRule{
+			params := defaultParameters
+			params.ChannelRules = map[lnwire.ShortChannelID]*ThresholdRule{
 				chanID1: chanRule,
 			}
 
 			testSuggestSwaps(
-				t, cfg, lnd, channels, rules, testCase.swaps,
+				t, newSuggestSwapsSetup(cfg, lnd, params),
+				testCase.swaps,
 			)
 		})
 	}
@@ -448,12 +453,15 @@ func TestSuggestSwaps(t *testing.T) {
 		t.Run(testCase.name, func(t *testing.T) {
 			cfg, lnd := newTestConfig()
 
-			channels := []lndclient.ChannelInfo{
+			lnd.Channels = []lndclient.ChannelInfo{
 				channel1,
 			}
 
+			params := defaultParameters
+			params.ChannelRules = testCase.rules
+
 			testSuggestSwaps(
-				t, cfg, lnd, channels, testCase.rules,
+				t, newSuggestSwapsSetup(cfg, lnd, params),
 				testCase.swaps,
 			)
 		})
@@ -513,40 +521,78 @@ func TestFeeLimits(t *testing.T) {
 				return testCase.quote, nil
 			}
 
-			channels := []lndclient.ChannelInfo{
+			lnd.Channels = []lndclient.ChannelInfo{
 				channel1,
 			}
-			rules := map[lnwire.ShortChannelID]*ThresholdRule{
+
+			params := defaultParameters
+			params.ChannelRules = map[lnwire.ShortChannelID]*ThresholdRule{
 				chanID1: chanRule,
 			}
 
 			testSuggestSwaps(
-				t, cfg, lnd, channels, rules, testCase.expected,
+				t, newSuggestSwapsSetup(cfg, lnd, params),
+				testCase.expected,
 			)
 		})
 	}
 }
 
-// testSuggestSwaps tests getting swap suggestions.
-func testSuggestSwaps(t *testing.T, cfg *Config, lnd *test.LndMockServices,
-	channels []lndclient.ChannelInfo,
-	rules map[lnwire.ShortChannelID]*ThresholdRule,
+// testSuggestSwapsSetup contains the elements that are used to create a
+// suggest swaps test.
+type testSuggestSwapsSetup struct {
+	cfg    *Config
+	lnd    *test.LndMockServices
+	params Parameters
+}
+
+// newSuggestSwapsSetup creates a suggest swaps setup struct.
+func newSuggestSwapsSetup(cfg *Config, lnd *test.LndMockServices,
+	params Parameters) *testSuggestSwapsSetup {
+
+	return &testSuggestSwapsSetup{
+		cfg:    cfg,
+		lnd:    lnd,
+		params: params,
+	}
+}
+
+// testSuggestSwaps tests getting swap suggestions. It takes a setup struct
+// which contains custom setup for the test. If this struct is nil, it will
+// use the default parameters and setup two channels (channel1 + channel2) with
+// chanRule set for each.
+func testSuggestSwaps(t *testing.T, setup *testSuggestSwapsSetup,
 	expected []loop.OutRequest) {
 
 	t.Parallel()
 
-	// Create a mock lnd with the set of channels set in our test case and
-	// update our test case lnd to use these channels.
-	lnd.Channels = channels
+	// If our setup struct is nil, we replace it with our default test
+	// values.
+	if setup == nil {
+		cfg, lnd := newTestConfig()
+
+		lnd.Channels = []lndclient.ChannelInfo{
+			channel1, channel2,
+		}
+
+		params := defaultParameters
+		params.ChannelRules = map[lnwire.ShortChannelID]*ThresholdRule{
+			chanID1: chanRule,
+			chanID2: chanRule,
+		}
+
+		setup = &testSuggestSwapsSetup{
+			cfg:    cfg,
+			lnd:    lnd,
+			params: params,
+		}
+	}
 
 	// Create a new manager, get our current set of parameters and update
 	// them to use the rules set by the test.
-	manager := NewManager(cfg)
+	manager := NewManager(setup.cfg)
 
-	currentParams := manager.GetParameters()
-	currentParams.ChannelRules = rules
-
-	err := manager.SetParameters(currentParams)
+	err := manager.SetParameters(setup.params)
 	require.NoError(t, err)
 
 	actual, err := manager.SuggestSwaps(context.Background())