Fix linter warnings

Signed-off-by: Youyuan Wu <youyuanwu@outlook.com>

.golangci.yml

@@ -35,6 +35,8 @@ linters:
     - godot
     - exhaustivestruct
     - paralleltest
+    - varnamelen
+    - ireturn
     #- thelper
 
 issues:

date_test.go

@@ -168,6 +168,7 @@ func TestDate_Equal(t *testing.T) {
 	d2 := Date(time.Date(2020, 10, 11, 12, 13, 14, 15, time.UTC))
 	d3 := Date(time.Date(2020, 11, 12, 13, 14, 15, 16, time.UTC))
 
+	//nolint:gocritic
 	assert.True(t, d1.Equal(d1), "Same Date should Equal itself")
 	assert.True(t, d1.Equal(d2), "Date instances should be equal")
 	assert.False(t, d1.Equal(d3), "Date instances should not be equal")

format.go

@@ -76,6 +76,7 @@ type defaultFormats struct {
 
 // NewFormats creates a new formats registry seeded with the values from the default
 func NewFormats() Registry {
+	//nolint:forcetypeassert
 	return NewSeededFormats(Default.(*defaultFormats).data, nil)
 }
 

time_test.go

@@ -320,6 +320,7 @@ func TestDateTime_Equal(t *testing.T) {
 	dt1 := DateTime(time.Now())
 	dt2 := DateTime(time.Time(dt1).Add(time.Second))
 
+	//nolint:gocritic
 	assert.True(t, dt1.Equal(dt1), "DateTime instances should be equal")
 	assert.False(t, dt1.Equal(dt2), "DateTime instances should not be equal")
 }

ulid_test.go

@@ -299,6 +299,7 @@ func TestFormatULID_NewULID_and_Equal(t *testing.T) {
 	ulid2, err := NewULID()
 	assert.NoError(t, err)
 
+	//nolint:gocritic
 	assert.True(t, ulid1.Equal(ulid1), "ULID instances should be equal")
 	assert.False(t, ulid1.Equal(ulid2), "ULID instances should not be equal")