Add inventory item API (#43)

* Add an inventory item service to the client that supports list, get, and update

fixtures/inventory_item.json

@@ -0,0 +1,11 @@
+{
+    "inventory_item": {
+      "id": 808950810,
+      "sku": "new sku",
+      "created_at": "2018-10-29T06:05:58-04:00",
+      "updated_at": "2018-10-29T06:05:58-04:00",
+      "cost": "25.00",
+      "tracked": true,
+      "admin_graphql_api_id": "gid://shopify/InventoryItem/808950810"
+    }
+  }

fixtures/inventory_items.json

@@ -0,0 +1,31 @@
+{
+    "inventory_items": [
+      {
+        "id": 39072856,
+        "sku": "IPOD2008GREEN",
+        "created_at": "2018-10-29T06:05:58-04:00",
+        "updated_at": "2018-10-29T06:05:58-04:00",
+        "cost": "25.00",
+        "tracked": true,
+        "admin_graphql_api_id": "gid://shopify/InventoryItem/39072856"
+      },
+      {
+        "id": 457924702,
+        "sku": "IPOD2008BLACK",
+        "created_at": "2018-10-29T06:05:58-04:00",
+        "updated_at": "2018-10-29T06:05:58-04:00",
+        "cost": "25.00",
+        "tracked": true,
+        "admin_graphql_api_id": "gid://shopify/InventoryItem/457924702"
+      },
+      {
+        "id": 808950810,
+        "sku": "IPOD2008PINK",
+        "created_at": "2018-10-29T06:05:58-04:00",
+        "updated_at": "2018-10-29T06:05:58-04:00",
+        "cost": "25.00",
+        "tracked": true,
+        "admin_graphql_api_id": "gid://shopify/InventoryItem/808950810"
+      }
+    ]
+  }

goshopify.go

@@ -73,6 +73,7 @@ type Client struct {
 	Collect                    CollectService
 	Location                   LocationService
 	DiscountCode               DiscountCodeService
+	InventoryItem              InventoryItemService
 }
 
 // A general response error that follows a similar layout to Shopify's response
@@ -213,6 +214,7 @@ func NewClient(app App, shopName, token string) *Client {
 	c.Collect = &CollectServiceOp{client: c}
 	c.Location = &LocationServiceOp{client: c}
 	c.DiscountCode = &DiscountCodeServiceOp{client: c}
+	c.InventoryItem = &InventoryItemServiceOp{client: c}
 
 	return c
 }

inventory_item.go

@@ -0,0 +1,70 @@
+package goshopify
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/shopspring/decimal"
+)
+
+const inventoryItemsBasePath = "admin/inventory_items"
+
+// InventoryItemService is an interface for interacting with the
+// inventory items endpoints of the Shopify API
+// See https://help.shopify.com/en/api/reference/inventory/inventoryitem
+type InventoryItemService interface {
+	List(interface{}) ([]InventoryItem, error)
+	Get(int, interface{}) (*InventoryItem, error)
+	Update(InventoryItem) (*InventoryItem, error)
+}
+
+// InventoryItemServiceOp is the default implementation of the InventoryItemService interface
+type InventoryItemServiceOp struct {
+	client *Client
+}
+
+// InventoryItem represents a Shopify inventory item
+type InventoryItem struct {
+	ID                int              `json:"id,omitempty"`
+	SKU               string           `json:"sku,omitempty"`
+	CreatedAt         *time.Time       `json:"created_at,omitempty"`
+	UpdatedAt         *time.Time       `json:"updated_at,omitempty"`
+	Cost              *decimal.Decimal `json:"cost,omitempty"`
+	Tracked           *bool            `json:"tracked,omitempty"`
+	AdminGraphqlAPIID string           `json:"admin_graphql_api_id,omitempty"`
+}
+
+// InventoryItemResource is used for handling single item requests and responses
+type InventoryItemResource struct {
+	InventoryItem *InventoryItem `json:"inventory_item"`
+}
+
+// InventoryItemsResource is used for handling multiple item responsees
+type InventoryItemsResource struct {
+	InventoryItems []InventoryItem `json:"inventory_items"`
+}
+
+// List inventory items
+func (s *InventoryItemServiceOp) List(options interface{}) ([]InventoryItem, error) {
+	path := fmt.Sprintf("%s.json", inventoryItemsBasePath)
+	resource := new(InventoryItemsResource)
+	err := s.client.Get(path, resource, options)
+	return resource.InventoryItems, err
+}
+
+// Get a inventory item
+func (s *InventoryItemServiceOp) Get(id int, options interface{}) (*InventoryItem, error) {
+	path := fmt.Sprintf("%s/%d.json", inventoryItemsBasePath, id)
+	resource := new(InventoryItemResource)
+	err := s.client.Get(path, resource, options)
+	return resource.InventoryItem, err
+}
+
+// Update a inventory item
+func (s *InventoryItemServiceOp) Update(item InventoryItem) (*InventoryItem, error) {
+	path := fmt.Sprintf("%s/%d.json", inventoryItemsBasePath, item.ID)
+	wrappedData := InventoryItemResource{InventoryItem: &item}
+	resource := new(InventoryItemResource)
+	err := s.client.Put(path, wrappedData, resource)
+	return resource.InventoryItem, err
+}

inventory_item_test.go

@@ -0,0 +1,116 @@
+package goshopify
+
+import (
+	"testing"
+
+	httpmock "gopkg.in/jarcoal/httpmock.v1"
+)
+
+func inventoryItemTests(t *testing.T, item *InventoryItem) {
+	if item == nil {
+		t.Errorf("InventoryItem is nil")
+		return
+	}
+
+	expectedInt := 808950810
+	if item.ID != expectedInt {
+		t.Errorf("InventoryItem.ID returned %+v, expected %+v", item.ID, expectedInt)
+	}
+
+	expectedSKU := "new sku"
+	if item.SKU != expectedSKU {
+		t.Errorf("InventoryItem.SKU sku is %+v, expected %+v", item.SKU, expectedSKU)
+	}
+
+	if item.Cost == nil {
+		t.Errorf("InventoryItem.Cost is nil")
+		return
+	}
+
+	expectedCost := 25.00
+	costFloat, _ := item.Cost.Float64()
+	if costFloat != expectedCost {
+		t.Errorf("InventoryItem.Cost (float) is %+v, expected %+v", costFloat, expectedCost)
+	}
+}
+
+func inventoryItemsTests(t *testing.T, items []InventoryItem) {
+	expectedLen := 3
+	if len(items) != expectedLen {
+		t.Errorf("InventoryItems list lenth is %+v, expected %+v", len(items), expectedLen)
+	}
+}
+
+func TestInventoryItemsList(t *testing.T) {
+	setup()
+	defer teardown()
+
+	httpmock.RegisterResponder("GET", "https://fooshop.myshopify.com/admin/inventory_items.json",
+		httpmock.NewBytesResponder(200, loadFixture("inventory_items.json")))
+
+	items, err := client.InventoryItem.List(nil)
+	if err != nil {
+		t.Errorf("InventoryItems.List returned error: %v", err)
+	}
+
+	inventoryItemsTests(t, items)
+}
+
+func TestInventoryItemsListWithIDs(t *testing.T) {
+	setup()
+	defer teardown()
+
+	params := map[string]string{
+		"ids": "1,2",
+	}
+	httpmock.RegisterResponderWithQuery(
+		"GET",
+		"https://fooshop.myshopify.com/admin/inventory_items.json",
+		params,
+		httpmock.NewBytesResponder(200, loadFixture("inventory_items.json")),
+	)
+
+	options := ListOptions{
+		IDs: []int{1, 2},
+	}
+
+	items, err := client.InventoryItem.List(options)
+	if err != nil {
+		t.Errorf("InventoryItems.List returned error: %v", err)
+	}
+
+	inventoryItemsTests(t, items)
+}
+
+func TestInventoryItemGet(t *testing.T) {
+	setup()
+	defer teardown()
+
+	httpmock.RegisterResponder("GET", "https://fooshop.myshopify.com/admin/inventory_items/1.json",
+		httpmock.NewBytesResponder(200, loadFixture("inventory_item.json")))
+
+	item, err := client.InventoryItem.Get(1, nil)
+	if err != nil {
+		t.Errorf("InventoryItem.Get returned error: %v", err)
+	}
+
+	inventoryItemTests(t, item)
+}
+func TestInventoryItemUpdate(t *testing.T) {
+	setup()
+	defer teardown()
+
+	httpmock.RegisterResponder("PUT", "https://fooshop.myshopify.com/admin/inventory_items/1.json",
+		httpmock.NewBytesResponder(200, loadFixture("inventory_item.json")))
+
+	item := InventoryItem{
+		ID: 1,
+	}
+
+	updatedItem, err := client.InventoryItem.Update(item)
+	if err != nil {
+		t.Errorf("InentoryItem.Update returned error: %v", err)
+	}
+
+	inventoryItemTests(t, updatedItem)
+}