Add tests for paginator

paginator/paginator_test.go

@@ -0,0 +1,154 @@
+package paginator
+
+import (
+	"testing"
+
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+func TestSetTotalPages(t *testing.T) {
+	tests := []struct {
+		name         string
+		items        int // total no of items to be set
+		initialTotal int // intital total pages for the testcase
+		expected     int // expected value after SetTotalPages function call
+	}{
+		{"Less than one page", 5, 1, 5},
+		{"Exactly one page", 10, 1, 10},
+		{"More than one page", 15, 1, 15},
+		{"negative value for page", -10, 1, 1},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			model := New()
+			if model.TotalPages != tt.initialTotal {
+				model.SetTotalPages(tt.initialTotal)
+			}
+			model.SetTotalPages(tt.items)
+			if model.TotalPages != tt.expected {
+				t.Errorf("TotalPages = %d, expected %d", model.TotalPages, tt.expected)
+			}
+		})
+	}
+}
+
+func TestPrevPage(t *testing.T) {
+	tests := []struct {
+		name       string
+		totalPages int // Total pages to be set for the testcase
+		page       int // intital page for test
+		expected   int
+	}{
+		{"Go to previous page", 10, 1, 0},
+		{"Stay on first page", 5, 0, 0},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			model := New()
+			model.SetTotalPages(tt.totalPages)
+			model.Page = tt.page
+
+			model, _ = model.Update(tea.KeyMsg{Type: tea.KeyLeft, Alt: false, Runes: []rune{}})
+			if model.Page != tt.expected {
+				t.Errorf("PrevPage() = %d, expected %d", model.Page, tt.expected)
+			}
+		})
+	}
+}
+
+func TestNextPage(t *testing.T) {
+	tests := []struct {
+		name       string
+		totalPages int
+		page       int
+		expected   int
+	}{
+		{"Go to next page", 2, 0, 1},
+		{"Stay on last page", 2, 1, 1},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			model := New()
+			model.SetTotalPages(tt.totalPages)
+			model.Page = tt.page
+
+			model, _ = model.Update(tea.KeyMsg{Type: tea.KeyRight, Alt: false, Runes: []rune{}})
+			if model.Page != tt.expected {
+				t.Errorf("NextPage() = %d, expected %d", model.Page, tt.expected)
+			}
+		})
+	}
+}
+
+func TestOnLastPage(t *testing.T) {
+	tests := []struct {
+		name       string
+		page       int
+		totalPages int
+		expected   bool
+	}{
+		{"On last page", 1, 2, true},
+		{"Not on last page", 0, 2, false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			model := New()
+			model.SetTotalPages(tt.totalPages)
+			model.Page = tt.page
+
+			if result := model.OnLastPage(); result != tt.expected {
+				t.Errorf("OnLastPage() = %t, expected %t", result, tt.expected)
+			}
+		})
+	}
+}
+
+func TestOnFirstPage(t *testing.T) {
+	tests := []struct {
+		name       string
+		page       int
+		totalPages int
+		expected   bool
+	}{
+		{"On first page", 0, 2, true},
+		{"Not on first page", 1, 2, false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			model := New()
+			model.SetTotalPages(tt.totalPages)
+			model.Page = tt.page
+
+			if result := model.OnFirstPage(); result != tt.expected {
+				t.Errorf("OnFirstPage() = %t, expected %t", result, tt.expected)
+			}
+		})
+	}
+}
+
+func TestItemsOnPage(t *testing.T) {
+	testCases := []struct {
+		currentPage   int // current page to be set for the testcase
+		totalPages    int // Total pages to be set for the testcase
+		totalItems    int // Total items
+		expectedItems int // expected items on current page
+	}{
+		{1, 10, 10, 1},
+		{3, 10, 10, 1},
+		{7, 10, 10, 1},
+	}
+
+	for _, tc := range testCases {
+		model := New()
+		model.Page = tc.currentPage
+		model.SetTotalPages(tc.totalPages)
+		if actualItems := model.ItemsOnPage(tc.totalItems); actualItems != tc.expectedItems {
+			t.Errorf("ItemsOnPage() returned %d, expected %d for total items %d", actualItems, tc.expectedItems, tc.totalItems)
+		}
+	}
+}