Merge pull request #6 from nrfta/feat/add-sort-by

Add sort by to paging

models.go

@@ -2,8 +2,20 @@ package paging
 
 // PageArgs is used as the query inputs
 type PageArgs struct {
-	First *int    `json:"first,omitempty"`
-	After *string `json:"after,omitempty"`
+	First      *int    `json:"first,omitempty"`
+	After      *string `json:"after,omitempty"`
+	sortByCols []string
+	isDesc     bool
+}
+
+func WithSortBy(pa *PageArgs, isDesc bool, cols ...string) *PageArgs {
+	if pa == nil {
+		pa = &PageArgs{}
+	}
+
+	pa.isDesc = isDesc
+	pa.sortByCols = cols
+	return pa
 }
 
 // PageInfo is the base struct for building PageInfo. It expects inline functions for all the fields

offset_paginator.go

@@ -1,6 +1,8 @@
 package paging
 
 import (
+	"strings"
+
 	"github.com/volatiletech/sqlboiler/v4/queries/qm"
 )
 
@@ -11,6 +13,7 @@ type OffsetPaginator struct {
 	Limit    int
 	Offset   int
 	PageInfo PageInfo
+	orderBy  string
 }
 
 // NewOffsetPaginator creates a new offset paginator
@@ -34,10 +37,20 @@ func NewOffsetPaginator(
 
 	offset := DecodeOffsetCursor(page.After)
 
+	orderBy := "created_at"
+	if len(page.sortByCols) > 0 {
+		orderBy = strings.Join(page.sortByCols, ", ")
+	}
+
+	if page.isDesc {
+		orderBy = orderBy + " DESC"
+	}
+
 	return OffsetPaginator{
 		Limit:    limit,
 		Offset:   offset,
 		PageInfo: NewOffsetBasedPageInfo(&limit, totalCount, offset),
+		orderBy:  orderBy,
 	}
 }
 
@@ -46,5 +59,6 @@ func (p *OffsetPaginator) QueryMods() []qm.QueryMod {
 	return []qm.QueryMod{
 		qm.Offset(p.Offset),
 		qm.Limit(p.Limit),
+		qm.OrderBy(p.orderBy),
 	}
 }

orderby_test.go

@@ -0,0 +1,116 @@
+package paging
+
+import (
+	"testing"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+func TestGoPaging(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "GoPaging Suite")
+}
+
+var _ = Describe("Order By clause", func() {
+	var (
+		pa   *PageArgs
+		cols []string
+	)
+
+	BeforeEach(func() {
+		first := 0
+		after := "after"
+		pa = &PageArgs{
+			After: &after,
+			First: &first,
+		}
+		cols = []string{"col1", "col2"}
+	})
+
+	Describe("WithSortBy", func() {
+		It("should handle a nil PageArgs arg", func() {
+			pa := WithSortBy(nil, true, "col1")
+			Expect(pa).ToNot(BeNil())
+		})
+	})
+
+	It("should have zero values for basic PageArgs", func() {
+		Expect(pa.sortByCols).To(BeNil())
+		Expect(pa.isDesc).To(BeFalse())
+	})
+
+	Describe("Default", func() {
+		It("should use `created_at` for default orderby column", func() {
+			sut := NewOffsetPaginator(pa, 5)
+
+			Expect(sut.orderBy).To(Equal("created_at"))
+		})
+	})
+
+	Describe("Desc Flag & Cols", func() {
+		Describe("Desc = true", func() {
+			It("should set the PageArgs fields", func() {
+				pa = WithSortBy(pa, true, cols...)
+
+				Expect(pa.isDesc).To(BeTrue())
+				Expect(pa.sortByCols).To(ContainElements(cols))
+			})
+
+			It("should set the OffsetPaginator `orderBy` field", func() {
+				pa = WithSortBy(pa, true, cols...)
+				sut := NewOffsetPaginator(pa, 5)
+
+				Expect(sut.orderBy).To(Equal("col1, col2 DESC"))
+			})
+		})
+
+		Describe("Desc = false", func() {
+			It("should set the PageArgs fields", func() {
+				pa = WithSortBy(pa, false, cols...)
+
+				Expect(pa.isDesc).To(BeFalse())
+				Expect(pa.sortByCols).To(ContainElements(cols))
+			})
+
+			It("should set the OffsetPaginator `orderBy` field", func() {
+				pa = WithSortBy(pa, false, cols...)
+				sut := NewOffsetPaginator(pa, 5)
+
+				Expect(sut.orderBy).To(Equal("col1, col2"))
+			})
+		})
+	})
+
+	Describe("Desc Flag only", func() {
+		Describe("Desc = true", func() {
+			It("should set the PageArgs fields", func() {
+				pa = WithSortBy(pa, true)
+
+				Expect(pa.isDesc).To(BeTrue())
+			})
+
+			It("should set the OffsetPaginator `orderBy` field", func() {
+				pa = WithSortBy(pa, true)
+				sut := NewOffsetPaginator(pa, 5)
+
+				Expect(sut.orderBy).To(Equal("created_at DESC"))
+			})
+		})
+
+		Describe("Desc = false", func() {
+			It("should set the PageArgs fields", func() {
+				pa = WithSortBy(pa, false)
+
+				Expect(pa.isDesc).To(BeFalse())
+			})
+
+			It("should set the OffsetPaginator `orderBy` field", func() {
+				pa = WithSortBy(pa, false)
+				sut := NewOffsetPaginator(pa, 5)
+
+				Expect(sut.orderBy).To(Equal("created_at"))
+			})
+		})
+	})
+})

go_paging_suite_test.go → tests/go_paging_suite_test.go

@@ -9,5 +9,5 @@ import (
 
 func TestGoPaging(t *testing.T) {
 	RegisterFailHandler(Fail)
-	RunSpecs(t, "GoPaging Suite")
+	RunSpecs(t, "GoPaging Test Suite")
 }

offset_paginator_test.go → tests/offset_paginator_test.go

@@ -74,5 +74,8 @@ var _ = Describe("OffsetPaginator", func() {
 
 		qm2 := reflect.TypeOf(mods[1]).String()
 		Expect(qm2).To(Equal("qm.limitQueryMod"))
+
+		qm3 := reflect.TypeOf(mods[2]).String()
+		Expect(qm3).To(Equal("qm.orderByQueryMod"))
 	})
 })