Added pager tests.

controller/controller_test.go

@@ -30,6 +30,6 @@ func TestMain(m *testing.M) {
 }
 
 func newContext(url string) echo.Context {
-	req := httptest.NewRequest(http.MethodPost, url, strings.NewReader(""))
+	req := httptest.NewRequest(http.MethodGet, url, strings.NewReader(""))
 	return c.Web.NewContext(req, httptest.NewRecorder())
 }

controller/page.go

@@ -104,26 +104,26 @@ type Page struct {
 	}
 }
 
-// NewPage creates and initiatizes a new page for a given request context
-func NewPage(c echo.Context) Page {
+// NewPage creates and initiatizes a new Page for a given request context
+func NewPage(ctx echo.Context) Page {
 	p := Page{
-		Context:    c,
-		ToURL:      c.Echo().Reverse,
-		Path:       c.Request().URL.Path,
-		URL:        c.Request().URL.String(),
+		Context:    ctx,
+		ToURL:      ctx.Echo().Reverse,
+		Path:       ctx.Request().URL.Path,
+		URL:        ctx.Request().URL.String(),
 		StatusCode: http.StatusOK,
-		Pager:      NewPager(c),
+		Pager:      NewPager(ctx, DefaultItemsPerPage),
 		Headers:    make(map[string]string),
-		RequestID:  c.Response().Header().Get(echo.HeaderXRequestID),
+		RequestID:  ctx.Response().Header().Get(echo.HeaderXRequestID),
 	}
 
 	p.IsHome = p.Path == "/"
 
-	if csrf := c.Get(echomw.DefaultCSRFConfig.ContextKey); csrf != nil {
+	if csrf := ctx.Get(echomw.DefaultCSRFConfig.ContextKey); csrf != nil {
 		p.CSRF = csrf.(string)
 	}
 
-	if u := c.Get(context.AuthenticatedUserKey); u != nil {
+	if u := ctx.Get(context.AuthenticatedUserKey); u != nil {
 		p.IsAuth = true
 	}
 

controller/page_test.go

@@ -23,7 +23,7 @@ func TestNewPage(t *testing.T) {
 	assert.Equal(t, "/", p.Path)
 	assert.Equal(t, "/", p.URL)
 	assert.Equal(t, http.StatusOK, p.StatusCode)
-	assert.Equal(t, NewPager(ctx), p.Pager)
+	assert.Equal(t, NewPager(ctx, DefaultItemsPerPage), p.Pager)
 	assert.Empty(t, p.Headers)
 	assert.True(t, p.IsHome)
 	assert.False(t, p.IsAuth)

controller/pager.go

@@ -10,23 +10,35 @@ import (
 const (
 	// DefaultItemsPerPage stores the default amount of items per page
 	DefaultItemsPerPage = 20
+
+	// PageQueryKey stores the query key used to indicate the current page
+	PageQueryKey = "page"
 )
 
+// Pager provides a mechanism to allow a user to page results via a query parameter
 type Pager struct {
-	Items        int
-	Page         int
+	// Items stores the total amount of items in the result set
+	Items int
+
+	// Page stores the current page number
+	Page int
+
+	// ItemsPerPage stores the amount of items to display per page
 	ItemsPerPage int
-	Pages        int
+
+	// Pages stores the total amount of pages in the result set
+	Pages int
 }
 
-func NewPager(c echo.Context) Pager {
+// NewPager creates a new Pager
+func NewPager(ctx echo.Context, itemsPerPage int) Pager {
 	p := Pager{
-		ItemsPerPage: DefaultItemsPerPage,
+		ItemsPerPage: itemsPerPage,
 		Page:         1,
 	}
 
-	if page := c.QueryParam("page"); page != "" {
-		if pageInt, err := strconv.Atoi(page); err != nil {
+	if page := ctx.QueryParam(PageQueryKey); page != "" {
+		if pageInt, err := strconv.Atoi(page); err == nil {
 			if pageInt > 0 {
 				p.Page = pageInt
 			}
@@ -36,6 +48,9 @@ func NewPager(c echo.Context) Pager {
 	return p
 }
 
+// SetItems sets the amount of items in total for the pager and calculate the amount
+// of total pages based off on the item per page.
+// This should be used rather than setting either items or pages directly.
 func (p *Pager) SetItems(items int) {
 	p.Items = items
 	p.Pages = int(math.Ceil(float64(items) / float64(p.ItemsPerPage)))
@@ -45,14 +60,18 @@ func (p *Pager) SetItems(items int) {
 	}
 }
 
+// IsBeginning determines if the pager is at the beginning of the pages
 func (p *Pager) IsBeginning() bool {
 	return p.Page == 1
 }
 
+// IsEnd determines if the pager is at the end of the pages
 func (p *Pager) IsEnd() bool {
 	return p.Page >= p.Pages
 }
 
+// GetOffset determines the offset of the results in order to get the items for
+// the current page
 func (p *Pager) GetOffset() int {
 	if p.Page == 0 {
 		p.Page = 1

controller/pager_test.go

@@ -0,0 +1,65 @@
+package controller
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNewPager(t *testing.T) {
+	ctx := newContext("/")
+	pgr := NewPager(ctx, 10)
+	assert.Equal(t, 10, pgr.ItemsPerPage)
+	assert.Equal(t, 1, pgr.Page)
+	assert.Equal(t, 0, pgr.Items)
+	assert.Equal(t, 0, pgr.Pages)
+
+	ctx = newContext(fmt.Sprintf("/abc?%s=%d", PageQueryKey, 2))
+	pgr = NewPager(ctx, 10)
+	assert.Equal(t, 2, pgr.Page)
+
+	ctx = newContext(fmt.Sprintf("/abc?%s=%d", PageQueryKey, -2))
+	pgr = NewPager(ctx, 10)
+	assert.Equal(t, 1, pgr.Page)
+}
+
+func TestPager_SetItems(t *testing.T) {
+	ctx := newContext("/")
+	pgr := NewPager(ctx, 20)
+	pgr.SetItems(100)
+	assert.Equal(t, 100, pgr.Items)
+	assert.Equal(t, 5, pgr.Pages)
+}
+
+func TestPager_IsBeginning(t *testing.T) {
+	ctx := newContext("/")
+	pgr := NewPager(ctx, 20)
+	pgr.Pages = 10
+	assert.True(t, pgr.IsBeginning())
+	pgr.Page = 2
+	assert.False(t, pgr.IsBeginning())
+	pgr.Page = 1
+	assert.True(t, pgr.IsBeginning())
+}
+
+func TestPager_IsEnd(t *testing.T) {
+	ctx := newContext("/")
+	pgr := NewPager(ctx, 20)
+	pgr.Pages = 10
+	assert.False(t, pgr.IsEnd())
+	pgr.Page = 10
+	assert.True(t, pgr.IsEnd())
+	pgr.Page = 1
+	assert.False(t, pgr.IsEnd())
+}
+
+func TestPager_GetOffset(t *testing.T) {
+	ctx := newContext("/")
+	pgr := NewPager(ctx, 20)
+	assert.Equal(t, 0, pgr.GetOffset())
+	pgr.Page = 2
+	assert.Equal(t, 20, pgr.GetOffset())
+	pgr.Page = 3
+	assert.Equal(t, 40, pgr.GetOffset())
+}