test: add a test for ProcessReceipt function and abstract test cases …

…into a separate file

cmd/handlers/handlers_test.go

@@ -0,0 +1,96 @@
+package handlers
+
+import (
+	"bytes"
+	"encoding/json"
+	"log"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"kweeuhree.receipt-processor-challenge/cmd/helpers"
+	"kweeuhree.receipt-processor-challenge/cmd/utils"
+	"kweeuhree.receipt-processor-challenge/internal/models"
+)
+
+var handlers *Handlers
+var receiptStore *models.ReceiptStore
+
+func TestMain(m *testing.M) {
+	receiptStore = models.NewStore()
+	utils := &utils.Utils{}
+	helpers := &helpers.Helpers{}
+	handlers = NewHandlers(log.Default(), receiptStore, utils, helpers)
+	m.Run()
+}
+
+func TestProcessReceipt(t *testing.T) {
+	tests := []struct {
+		name           string
+		input          ReceiptInput
+		expectedStatus int
+		expectedID     string
+		expectedField  string
+		expectedError  string
+	}{
+		{"Valid receipt", *ValidReceipt, http.StatusOK, "123-qwe-456-rty-7890", "", ""},
+		{"No retailer", *NoRetailerReceipt, http.StatusBadRequest, "", "retailerName", "This field cannot be blank"},
+		{"No items", *NoItemsReceipt, http.StatusBadRequest, "", "items", "This field must have at least one object"},
+		{"No total", *NoTotalReceipt, http.StatusBadRequest, "", "total", "This field cannot be blank"},
+		{"Invalid total", *InvalidTotalReceipt, http.StatusBadRequest, "", "total", "This field must be a valid number"},
+	}
+
+	for _, entry := range tests {
+		t.Run(entry.name, func(t *testing.T) {
+			// Prepare input for the request construction
+			body, err := json.Marshal(entry.input)
+			if err != nil {
+				t.Fatalf("Failed to marshal input: %v", err)
+			}
+			// Create request and response
+			req := httptest.NewRequest("POST", "/receipts/process", bytes.NewBuffer(body))
+			req.Header.Set("Content-Type", "application/json")
+			resp := httptest.NewRecorder()
+
+			// Test ProcessReceipt function
+			handlers.ProcessReceipt(resp, req)
+
+			// Check the response status
+			if status := resp.Code; status != entry.expectedStatus {
+				t.Errorf("Expected status %d, got %d", entry.expectedStatus, status)
+			}
+
+			// Check if response status matches the expected one
+			if entry.expectedStatus == http.StatusOK {
+				// If so, check if the received id matches the expected one
+				var response IdResponse
+				if err := json.NewDecoder(resp.Body).Decode(&response); err != nil {
+					t.Fatalf("Failed to decode response: %v", err)
+				}
+				if response.ID == "" {
+					t.Errorf("Expected id %s, but did not receive any", entry.expectedID)
+				}
+			} else {
+				// If response status does not match, check errors
+				var response map[string]interface{}
+				if err := json.NewDecoder(resp.Body).Decode(&response); err != nil {
+					t.Fatalf("failed to decode error response: %v", err)
+				}
+
+				// Check both field and field error
+				for field, fieldError := range response {
+					if field != entry.expectedField {
+						t.Errorf("Expected %s, received field %s", entry.expectedField, field)
+					}
+					if fieldError != entry.expectedError {
+						t.Errorf("Expected %s, received field %s", entry.expectedError, fieldError)
+					}
+				}
+			}
+
+			t.Cleanup(func() {
+				receiptStore = models.NewStore()
+			})
+		})
+	}
+}

cmd/handlers/handlers_test_cases.go

@@ -0,0 +1,48 @@
+package handlers
+
+import "kweeuhree.receipt-processor-challenge/internal/models"
+
+var ValidReceipt = &ReceiptInput{
+	Retailer:     "Target",
+	PurchaseDate: "2022-01-02",
+	PurchaseTime: "13:13",
+	Total:        "1.25",
+	Items: []models.Item{
+		{ShortDescription: "Pepsi - 12-oz", Price: "1.25"},
+	},
+}
+
+var NoRetailerReceipt = &ReceiptInput{
+	PurchaseDate: "2022-01-02",
+	PurchaseTime: "13:13",
+	Total:        "1.25",
+	Items: []models.Item{
+		{ShortDescription: "Pepsi - 12-oz", Price: "1.25"},
+	},
+}
+
+var NoTotalReceipt = &ReceiptInput{
+	Retailer:     "Target",
+	PurchaseDate: "2022-01-01",
+	PurchaseTime: "12:00",
+	Items: []models.Item{
+		{ShortDescription: "Pepsi - 12-oz", Price: "1.25"},
+	},
+}
+
+var InvalidTotalReceipt = &ReceiptInput{
+	Retailer:     "Target",
+	PurchaseDate: "2022-01-01",
+	PurchaseTime: "12:00",
+	Total:        "hello-world",
+	Items: []models.Item{
+		{ShortDescription: "Pepsi - 12-oz", Price: "1.25"},
+	},
+}
+
+var NoItemsReceipt = &ReceiptInput{
+	Retailer:     "Target",
+	PurchaseDate: "2022-01-01",
+	PurchaseTime: "12:00",
+	Total:        "1.25",
+}