Merge pull request #2468 from SchrodingersGat/merge-stock-items

Merge stock items

InvenTree/InvenTree/status_codes.py

@@ -252,6 +252,9 @@ class StockHistoryCode(StatusCode):
     SPLIT_FROM_PARENT = 40
     SPLIT_CHILD_ITEM = 42
 
+    # Stock merging operations
+    MERGED_STOCK_ITEMS = 45
+
     # Build order codes
     BUILD_OUTPUT_CREATED = 50
     BUILD_OUTPUT_COMPLETED = 55
@@ -288,6 +291,8 @@ class StockHistoryCode(StatusCode):
         SPLIT_FROM_PARENT: _('Split from parent item'),
         SPLIT_CHILD_ITEM: _('Split child item'),
 
+        MERGED_STOCK_ITEMS: _('Merged stock items'),
+
         SENT_TO_CUSTOMER: _('Sent to customer'),
         RETURNED_FROM_CUSTOMER: _('Returned from customer'),
 

InvenTree/InvenTree/version.py

@@ -12,10 +12,14 @@ import common.models
 INVENTREE_SW_VERSION = "0.6.0 dev"
 
 # InvenTree API version
-INVENTREE_API_VERSION = 21
+INVENTREE_API_VERSION = 22
 
 """
 Increment this API version number whenever there is a significant change to the API that any clients need to know about
+
+v22 -> 2021-12-20
+    - Adds API endpoint to "merge" multiple stock items
+
 v21 -> 2021-12-04
     - Adds support for multiple "Shipments" against a SalesOrder
     - Refactors process for stock allocation against a SalesOrder

InvenTree/order/models.py

@@ -628,28 +628,30 @@ class SalesOrder(Order):
         Throws a ValidationError if cannot be completed.
         """
 
-        # Order without line items cannot be completed
-        if self.lines.count() == 0:
-            if raise_error:
+        try:
+
+            # Order without line items cannot be completed
+            if self.lines.count() == 0:
                 raise ValidationError(_('Order cannot be completed as no parts have been assigned'))
 
-        # Only a PENDING order can be marked as SHIPPED
-        elif self.status != SalesOrderStatus.PENDING:
-            if raise_error:
+            # Only a PENDING order can be marked as SHIPPED
+            elif self.status != SalesOrderStatus.PENDING:
                 raise ValidationError(_('Only a pending order can be marked as complete'))
 
-        elif self.pending_shipment_count > 0:
-            if raise_error:
+            elif self.pending_shipment_count > 0:
                 raise ValidationError(_("Order cannot be completed as there are incomplete shipments"))
 
-        elif self.pending_line_count > 0:
-            if raise_error:
+            elif self.pending_line_count > 0:
                 raise ValidationError(_("Order cannot be completed as there are incomplete line items"))
 
-        else:
-            return True
+        except ValidationError as e:
 
-        return False
+            if raise_error:
+                raise e
+            else:
+                return False
+
+        return True
 
     def complete_order(self, user):
         """

InvenTree/script/translation_stats.py

@@ -4,6 +4,7 @@ This script calculates translation coverage for various languages
 
 import os
 import json
+import sys
 
 
 def calculate_coverage(filename):
@@ -42,7 +43,7 @@ if __name__ == '__main__':
     locales = {}
     locales_perc = {}
 
-    print("InvenTree translation coverage:")
+    verbose = '-v' in sys.argv
 
     for locale in os.listdir(LC_DIR):
         path = os.path.join(LC_DIR, locale)
@@ -53,7 +54,10 @@ if __name__ == '__main__':
             if os.path.exists(locale_file) and os.path.isfile(locale_file):
                 locales[locale] = locale_file
 
-    print("-" * 16)
+    if verbose:
+        print("-" * 16)
+
+    percentages = []
 
     for locale in locales.keys():
         locale_file = locales[locale]
@@ -66,11 +70,23 @@ if __name__ == '__main__':
         else:
             percentage = 0
 
-        print(f"| {locale.ljust(4, ' ')} : {str(percentage).rjust(4, ' ')}% |")
+        if verbose:
+            print(f"| {locale.ljust(4, ' ')} : {str(percentage).rjust(4, ' ')}% |")
+
         locales_perc[locale] = percentage
 
-    print("-" * 16)
+        percentages.append(percentage)
+
+    if verbose:
+        print("-" * 16)
 
     # write locale stats
     with open(STAT_FILE, 'w') as target:
         json.dump(locales_perc, target)
+
+    if len(percentages) > 0:
+        avg = int(sum(percentages) / len(percentages))
+    else:
+        avg = 0
+
+    print(f"InvenTree translation coverage: {avg}%")

InvenTree/stock/api.py

@@ -180,6 +180,20 @@ class StockAssign(generics.CreateAPIView):
         return ctx
 
 
+class StockMerge(generics.CreateAPIView):
+    """
+    API endpoint for merging multiple stock items
+    """
+
+    queryset = StockItem.objects.none()
+    serializer_class = StockSerializers.StockMergeSerializer
+
+    def get_serializer_context(self):
+        ctx = super().get_serializer_context()
+        ctx['request'] = self.request
+        return ctx
+
+
 class StockLocationList(generics.ListCreateAPIView):
     """
     API endpoint for list view of StockLocation objects:
@@ -1213,6 +1227,7 @@ stock_api_urls = [
     url(r'^remove/', StockRemove.as_view(), name='api-stock-remove'),
     url(r'^transfer/', StockTransfer.as_view(), name='api-stock-transfer'),
     url(r'^assign/', StockAssign.as_view(), name='api-stock-assign'),
+    url(r'^merge/', StockMerge.as_view(), name='api-stock-merge'),
 
     # StockItemAttachment API endpoints
     url(r'^attachment/', include([

InvenTree/stock/fixtures/stock.yaml

@@ -114,19 +114,6 @@
     lft: 0
     rght: 0
 
-- model: stock.stockitem
-  pk: 501
-  fields:
-    part: 10001
-    location: 7
-    batch: "AAA"
-    quantity: 1
-    serial: 1
-    level: 0
-    tree_id: 0
-    lft: 0
-    rght: 0
-
 - model: stock.stockitem
   pk: 501
   fields:

InvenTree/stock/migrations/0073_alter_stockitem_belongs_to.py

@@ -0,0 +1,19 @@
+# Generated by Django 3.2.10 on 2021-12-20 21:49
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('stock', '0072_remove_stockitem_scheduled_for_deletion'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='stockitem',
+            name='belongs_to',
+            field=models.ForeignKey(blank=True, help_text='Is this item installed in another item?', null=True, on_delete=django.db.models.deletion.CASCADE, related_name='installed_parts', to='stock.stockitem', verbose_name='Installed In'),
+        ),
+    ]

InvenTree/stock/models.py

@@ -455,6 +455,7 @@ class StockItem(MPTTModel):
 
     uid = models.CharField(blank=True, max_length=128, help_text=("Unique identifier field"))
 
+    # Note: When a StockItem is deleted, a pre_delete signal handles the parent/child relationship
     parent = TreeForeignKey(
         'self',
         verbose_name=_('Parent Stock Item'),
@@ -477,6 +478,7 @@ class StockItem(MPTTModel):
         help_text=_('Select a matching supplier part for this stock item')
     )
 
+    # Note: When a StockLocation is deleted, stock items are updated via a signal
     location = TreeForeignKey(
         StockLocation, on_delete=models.DO_NOTHING,
         verbose_name=_('Stock Location'),
@@ -492,10 +494,11 @@ class StockItem(MPTTModel):
         help_text=_('Packaging this stock item is stored in')
     )
 
+    # When deleting a stock item with installed items, those installed items are also installed
     belongs_to = models.ForeignKey(
         'self',
         verbose_name=_('Installed In'),
-        on_delete=models.DO_NOTHING,
+        on_delete=models.CASCADE,
         related_name='installed_parts', blank=True, null=True,
         help_text=_('Is this item installed in another item?')
     )
@@ -800,14 +803,14 @@ class StockItem(MPTTModel):
     def can_delete(self):
         """ Can this stock item be deleted? It can NOT be deleted under the following circumstances:
 
-        - Has child StockItems
+        - Has installed stock items
         - Has a serial number and is tracked
         - Is installed inside another StockItem
         - It has been assigned to a SalesOrder
         - It has been assigned to a BuildOrder
         """
 
-        if self.child_count > 0:
+        if self.installed_item_count() > 0:
             return False
 
         if self.part.trackable and self.serial is not None:
@@ -853,20 +856,13 @@ class StockItem(MPTTModel):
 
         return installed
 
-    def installedItemCount(self):
+    def installed_item_count(self):
         """
         Return the number of stock items installed inside this one.
         """
 
         return self.installed_parts.count()
 
-    def hasInstalledItems(self):
-        """
-        Returns true if this stock item has other stock items installed in it.
-        """
-
-        return self.installedItemCount() > 0
-
     @transaction.atomic
     def installStockItem(self, other_item, quantity, user, notes):
         """
@@ -1153,6 +1149,124 @@ class StockItem(MPTTModel):
             result.stock_item = self
             result.save()
 
+    def can_merge(self, other=None, raise_error=False, **kwargs):
+        """
+        Check if this stock item can be merged into another stock item
+        """
+
+        allow_mismatched_suppliers = kwargs.get('allow_mismatched_suppliers', False)
+
+        allow_mismatched_status = kwargs.get('allow_mismatched_status', False)
+
+        try:
+            # Generic checks (do not rely on the 'other' part)
+            if self.sales_order:
+                raise ValidationError(_('Stock item has been assigned to a sales order'))
+
+            if self.belongs_to:
+                raise ValidationError(_('Stock item is installed in another item'))
+
+            if self.installed_item_count() > 0:
+                raise ValidationError(_('Stock item contains other items'))
+
+            if self.customer:
+                raise ValidationError(_('Stock item has been assigned to a customer'))
+
+            if self.is_building:
+                raise ValidationError(_('Stock item is currently in production'))
+
+            if self.serialized:
+                raise ValidationError(_("Serialized stock cannot be merged"))
+
+            if other:
+                # Specific checks (rely on the 'other' part)
+
+                # Prevent stock item being merged with itself
+                if self == other:
+                    raise ValidationError(_('Duplicate stock items'))
+
+                # Base part must match
+                if self.part != other.part:
+                    raise ValidationError(_("Stock items must refer to the same part"))
+
+                # Check if supplier part references match
+                if self.supplier_part != other.supplier_part and not allow_mismatched_suppliers:
+                    raise ValidationError(_("Stock items must refer to the same supplier part"))
+
+                # Check if stock status codes match
+                if self.status != other.status and not allow_mismatched_status:
+                    raise ValidationError(_("Stock status codes must match"))
+
+        except ValidationError as e:
+            if raise_error:
+                raise e
+            else:
+                return False
+
+        return True
+
+    @transaction.atomic
+    def merge_stock_items(self, other_items, raise_error=False, **kwargs):
+        """
+        Merge another stock item into this one; the two become one!
+
+        *This* stock item subsumes the other, which is essentially deleted:
+
+        - The quantity of this StockItem is increased
+        - Tracking history for the *other* item is deleted
+        - Any allocations (build order, sales order) are moved to this StockItem
+        """
+
+        if len(other_items) == 0:
+            return
+
+        user = kwargs.get('user', None)
+        location = kwargs.get('location', None)
+        notes = kwargs.get('notes', None)
+
+        parent_id = self.parent.pk if self.parent else None
+
+        for other in other_items:
+            # If the stock item cannot be merged, return
+            if not self.can_merge(other, raise_error=raise_error, **kwargs):
+                return
+
+        for other in other_items:
+
+            self.quantity += other.quantity
+
+            # Any "build order allocations" for the other item must be assigned to this one
+            for allocation in other.allocations.all():
+
+                allocation.stock_item = self
+                allocation.save()
+
+            # Any "sales order allocations" for the other item must be assigned to this one
+            for allocation in other.sales_order_allocations.all():
+
+                allocation.stock_item = self()
+                allocation.save()
+
+            # Prevent atomicity issues when we are merging our own "parent" part in
+            if parent_id and parent_id == other.pk:
+                self.parent = None
+                self.save()
+
+            other.delete()
+
+        self.add_tracking_entry(
+            StockHistoryCode.MERGED_STOCK_ITEMS,
+            user,
+            quantity=self.quantity,
+            notes=notes,
+            deltas={
+                'location': location.pk,
+            }
+        )
+
+        self.location = location
+        self.save()
+
     @transaction.atomic
     def splitStock(self, quantity, location, user, **kwargs):
         """ Split this stock item into two items, in the same location.
@@ -1648,7 +1762,8 @@ class StockItem(MPTTModel):
 
 @receiver(pre_delete, sender=StockItem, dispatch_uid='stock_item_pre_delete_log')
 def before_delete_stock_item(sender, instance, using, **kwargs):
-    """ Receives pre_delete signal from StockItem object.
+    """
+    Receives pre_delete signal from StockItem object.
 
     Before a StockItem is deleted, ensure that each child object is updated,
     to point to the new parent item.

InvenTree/stock/serializers.py

@@ -674,6 +674,149 @@ class StockAssignmentSerializer(serializers.Serializer):
                 )
 
 
+class StockMergeItemSerializer(serializers.Serializer):
+    """
+    Serializer for a single StockItem within the StockMergeSerializer class.
+
+    Here, the individual StockItem is being checked for merge compatibility.
+    """
+
+    class Meta:
+        fields = [
+            'item',
+        ]
+
+    item = serializers.PrimaryKeyRelatedField(
+        queryset=StockItem.objects.all(),
+        many=False,
+        allow_null=False,
+        required=True,
+        label=_('Stock Item'),
+    )
+
+    def validate_item(self, item):
+
+        # Check that the stock item is able to be merged
+        item.can_merge(raise_error=True)
+
+        return item
+
+
+class StockMergeSerializer(serializers.Serializer):
+    """
+    Serializer for merging two (or more) stock items together
+    """
+
+    class Meta:
+        fields = [
+            'items',
+            'location',
+            'notes',
+            'allow_mismatched_suppliers',
+            'allow_mismatched_status',
+        ]
+
+    items = StockMergeItemSerializer(
+        many=True,
+        required=True,
+    )
+
+    location = serializers.PrimaryKeyRelatedField(
+        queryset=StockLocation.objects.all(),
+        many=False,
+        required=True,
+        allow_null=False,
+        label=_('Location'),
+        help_text=_('Destination stock location'),
+    )
+
+    notes = serializers.CharField(
+        required=False,
+        allow_blank=True,
+        label=_('Notes'),
+        help_text=_('Stock merging notes'),
+    )
+
+    allow_mismatched_suppliers = serializers.BooleanField(
+        required=False,
+        label=_('Allow mismatched suppliers'),
+        help_text=_('Allow stock items with different supplier parts to be merged'),
+    )
+
+    allow_mismatched_status = serializers.BooleanField(
+        required=False,
+        label=_('Allow mismatched status'),
+        help_text=_('Allow stock items with different status codes to be merged'),
+    )
+
+    def validate(self, data):
+
+        data = super().validate(data)
+
+        items = data['items']
+
+        if len(items) < 2:
+            raise ValidationError(_('At least two stock items must be provided'))
+
+        unique_items = set()
+
+        # The "base item" is the first item
+        base_item = items[0]['item']
+
+        data['base_item'] = base_item
+
+        # Ensure stock items are unique!
+        for element in items:
+            item = element['item']
+
+            if item.pk in unique_items:
+                raise ValidationError(_('Duplicate stock items'))
+
+            unique_items.add(item.pk)
+
+            # Checks from here refer to the "base_item"
+            if item == base_item:
+                continue
+
+            # Check that this item can be merged with the base_item
+            item.can_merge(
+                raise_error=True,
+                other=base_item,
+                allow_mismatched_suppliers=data.get('allow_mismatched_suppliers', False),
+                allow_mismatched_status=data.get('allow_mismatched_status', False),
+            )
+
+        return data
+
+    def save(self):
+        """
+        Actually perform the stock merging action.
+        At this point we are confident that the merge can take place
+        """
+
+        data = self.validated_data
+
+        base_item = data['base_item']
+        items = data['items'][1:]
+
+        request = self.context['request']
+        user = getattr(request, 'user', None)
+
+        items = []
+
+        for item in data['items'][1:]:
+            items.append(item['item'])
+
+        base_item.merge_stock_items(
+            items,
+            allow_mismatched_suppliers=data.get('allow_mismatched_suppliers', False),
+            allow_mismatched_status=data.get('allow_mismatched_status', False),
+            user=user,
+            location=data['location'],
+            notes=data.get('notes', None)
+        )
+
+
 class StockAdjustmentItemSerializer(serializers.Serializer):
     """
     Serializer for a single StockItem within a stock adjument request.
@@ -837,7 +980,7 @@ class StockTransferSerializer(StockAdjustmentSerializer):
 
     def validate(self, data):
 
-        super().validate(data)
+        data = super().validate(data)
 
         # TODO: Any specific validation of location field?
 

InvenTree/stock/templates/stock/item_base.html

@@ -274,14 +274,6 @@
     <div class='alert alert-block alert-warning'>
         {% trans "This stock item is serialized - it has a unique serial number and the quantity cannot be adjusted." %}
     </div>
-    {% elif item.child_count > 0 %}
-    <div class='alert alert-block alert-warning'>
-        {% trans "This stock item cannot be deleted as it has child items" %}
-    </div>
-    {% elif item.delete_on_deplete and item.can_delete %}
-    <div class='alert alert-block alert-warning'>
-        {% trans "This stock item will be automatically deleted when all stock is depleted." %}
-    </div>
     {% endif %}
     
 </div>

InvenTree/stock/test_api.py

@@ -842,3 +842,189 @@ class StockAssignTest(StockAPITestCase):
 
         # 5 stock items should now have been assigned to this customer
         self.assertEqual(customer.assigned_stock.count(), 5)
+
+
+class StockMergeTest(StockAPITestCase):
+    """
+    Unit tests for merging stock items via the API
+    """
+
+    URL = reverse('api-stock-merge')
+
+    def setUp(self):
+
+        super().setUp()
+
+        self.part = part.models.Part.objects.get(pk=25)
+        self.loc = StockLocation.objects.get(pk=1)
+        self.sp_1 = company.models.SupplierPart.objects.get(pk=100)
+        self.sp_2 = company.models.SupplierPart.objects.get(pk=101)
+
+        self.item_1 = StockItem.objects.create(
+            part=self.part,
+            supplier_part=self.sp_1,
+            quantity=100,
+        )
+
+        self.item_2 = StockItem.objects.create(
+            part=self.part,
+            supplier_part=self.sp_2,
+            quantity=100,
+        )
+
+        self.item_3 = StockItem.objects.create(
+            part=self.part,
+            supplier_part=self.sp_2,
+            quantity=50,
+        )
+
+    def test_missing_data(self):
+        """
+        Test responses which are missing required data
+        """
+
+        # Post completely empty
+
+        data = self.post(
+            self.URL,
+            {},
+            expected_code=400
+        ).data
+
+        self.assertIn('This field is required', str(data['items']))
+        self.assertIn('This field is required', str(data['location']))
+
+        # Post with a location and empty items list
+        data = self.post(
+            self.URL,
+            {
+                'items': [],
+                'location': 1,
+            },
+            expected_code=400
+        ).data
+
+        self.assertIn('At least two stock items', str(data))
+
+    def test_invalid_data(self):
+        """
+        Test responses which have invalid data
+        """
+
+        # Serialized stock items should be rejected
+        data = self.post(
+            self.URL,
+            {
+                'items': [
+                    {
+                        'item': 501,
+                    },
+                    {
+                        'item': 502,
+                    }
+                ],
+                'location': 1,
+            },
+            expected_code=400,
+        ).data
+
+        self.assertIn('Serialized stock cannot be merged', str(data))
+
+        # Prevent item duplication
+
+        data = self.post(
+            self.URL,
+            {
+                'items': [
+                    {
+                        'item': 11,
+                    },
+                    {
+                        'item': 11,
+                    }
+                ],
+                'location': 1,
+            },
+            expected_code=400,
+        ).data
+
+        self.assertIn('Duplicate stock items', str(data))
+
+        # Check for mismatching stock items
+        data = self.post(
+            self.URL,
+            {
+                'items': [
+                    {
+                        'item': 1234,
+                    },
+                    {
+                        'item': 11,
+                    }
+                ],
+                'location': 1,
+            },
+            expected_code=400,
+        ).data
+
+        self.assertIn('Stock items must refer to the same part', str(data))
+
+        # Check for mismatching supplier parts
+        payload = {
+            'items': [
+                {
+                    'item': self.item_1.pk,
+                },
+                {
+                    'item': self.item_2.pk,
+                },
+            ],
+            'location': 1,
+        }
+
+        data = self.post(
+            self.URL,
+            payload,
+            expected_code=400,
+        ).data
+
+        self.assertIn('Stock items must refer to the same supplier part', str(data))
+
+    def test_valid_merge(self):
+        """
+        Test valid merging of stock items
+        """
+
+        # Check initial conditions
+        n = StockItem.objects.filter(part=self.part).count()
+        self.assertEqual(self.item_1.quantity, 100)
+
+        payload = {
+            'items': [
+                {
+                    'item': self.item_1.pk,
+                },
+                {
+                    'item': self.item_2.pk,
+                },
+                {
+                    'item': self.item_3.pk,
+                },
+            ],
+            'location': 1,
+            'allow_mismatched_suppliers': True,
+        }
+
+        self.post(
+            self.URL,
+            payload,
+            expected_code=201,
+        )
+
+        self.item_1.refresh_from_db()
+
+        # Stock quantity should have been increased!
+        self.assertEqual(self.item_1.quantity, 250)
+
+        # Total number of stock items has been reduced!
+        self.assertEqual(StockItem.objects.filter(part=self.part).count(), n - 2)

InvenTree/templates/js/translated/stock.js

@@ -52,6 +52,7 @@
     loadStockTestResultsTable,
     loadStockTrackingTable,
     loadTableFilters,
+    mergeStockItems,
     removeStockRow,
     serializeStockItem,
     stockItemFields,
@@ -595,17 +596,17 @@ function assignStockToCustomer(items, options={}) {
         buttons += '</div>';
 
         html += `
-            <tr id='stock_item_${pk}' class='stock-item'row'>
-                <td id='part_${pk}'>${thumbnail} ${part.full_name}</td>
-                <td id='stock_${pk}'>
-                    <div id='div_id_items_item_${pk}'>
-                        ${quantity}
-                        <div id='errors-items_item_${pk}'></div>
-                    </div>
-                </td>
-                <td id='location_${pk}'>${location}</td>
-                <td id='buttons_${pk}'>${buttons}</td>
-            </tr>
+        <tr id='stock_item_${pk}' class='stock-item-row'>
+            <td id='part_${pk}'>${thumbnail} ${part.full_name}</td>
+            <td id='stock_${pk}'>
+                <div id='div_id_items_item_${pk}'>
+                    ${quantity}
+                    <div id='errors-items_item_${pk}'></div>
+                </div>
+            </td>
+            <td id='location_${pk}'>${location}</td>
+            <td id='buttons_${pk}'>${buttons}</td>
+        </tr>
         `;
     }
 
@@ -615,13 +616,13 @@ function assignStockToCustomer(items, options={}) {
         method: 'POST',
         preFormContent: html,
         fields: {
-            'customer': {
+            customer: {
                 value: options.customer,
                 filters: {
                     is_customer: true,
                 },
             },
-            'notes': {},
+            notes: {},
         },
         confirm: true,
         confirmMessage: '{% trans "Confirm stock assignment" %}',
@@ -694,6 +695,184 @@ function assignStockToCustomer(items, options={}) {
 }
 
 
+/**
+ * Merge multiple stock items together
+ */
+function mergeStockItems(items, options={}) {
+
+    // Generate HTML content for the form
+    var html = `
+    <div class='alert alert-block alert-danger'>
+    <h5>{% trans "Warning: Merge operation cannot be reversed" %}</h5>
+    <strong>{% trans "Some information will be lost when merging stock items" %}:</strong>
+    <ul>
+        <li>{% trans "Stock transaction history will be deleted for merged items" %}</li>
+        <li>{% trans "Supplier part information will be deleted for merged items" %}</li>
+    </ul>
+    </div>
+    `;
+
+    html += `
+    <table class='table table-striped table-condensed' id='stock-merge-table'>
+    <thead>
+        <tr>
+            <th>{% trans "Part" %}</th>
+            <th>{% trans "Stock Item" %}</th>
+            <th>{% trans "Location" %}</th>
+            <th></th>
+        </tr>
+    </thead>
+    <tbody>
+    `;
+
+    // Keep track of how many "locations" there are
+    var locations = [];
+
+    for (var idx = 0; idx < items.length; idx++) {
+        var item = items[idx];
+
+        var pk = item.pk;
+
+        if (item.location && !locations.includes(item.location)) {
+            locations.push(item.location);
+        }
+
+        var part = item.part_detail;
+        var location = locationDetail(item, false);
+
+        var thumbnail = thumbnailImage(part.thumbnail || part.image);
+
+        var quantity = '';
+
+        if (item.serial && item.quantity == 1) {
+            quantity = `{% trans "Serial" %}: ${item.serial}`;
+        } else {
+            quantity = `{% trans "Quantity" %}: ${item.quantity}`;
+        }
+
+        quantity += stockStatusDisplay(item.status, {classes: 'float-right'});
+
+        var buttons = `<div class='btn-group' role='group'>`;
+
+        buttons += makeIconButton(
+            'fa-times icon-red',
+            'button-stock-item-remove',
+            pk,
+            '{% trans "Remove row" %}',
+        );
+
+        html += `
+        <tr id='stock_item_${pk}' class='stock-item-row'>
+            <td id='part_${pk}'>${thumbnail} ${part.full_name}</td>
+            <td id='stock_${pk}'>
+                <div id='div_id_items_item_${pk}'>
+                    ${quantity}
+                    <div id='errors-items_item_${pk}'></div>
+                </div>
+            </td>
+            <td id='location_${pk}'>${location}</td>
+            <td id='buttons_${pk}'>${buttons}</td>
+        </tr>
+        `;
+    }
+
+    html += '</tbody></table>';
+
+    var location = locations.length == 1 ? locations[0] : null;
+
+    constructForm('{% url "api-stock-merge" %}', {
+        method: 'POST',
+        preFormContent: html,
+        fields: {
+            location: {
+                value: location,
+                icon: 'fa-sitemap',
+            },
+            notes: {},
+            allow_mismatched_suppliers: {},
+            allow_mismatched_status: {},
+        },
+        confirm: true,
+        confirmMessage: '{% trans "Confirm stock item merge" %}',
+        title: '{% trans "Merge Stock Items" %}',
+        afterRender: function(fields, opts) {
+            // Add button callbacks to remove rows
+            $(opts.modal).find('.button-stock-item-remove').click(function() {
+                var pk = $(this).attr('pk');
+
+                $(opts.modal).find(`#stock_item_${pk}`).remove();
+            });
+        },
+        onSubmit: function(fields, opts) {
+
+            // Extract data elements from the form
+            var data = {
+                items: [],
+            };
+
+            var item_pk_values = [];
+
+            items.forEach(function(item) {
+                var pk = item.pk;
+
+                // Does the row still exist in the form?
+                var row = $(opts.modal).find(`#stock_item_${pk}`);
+
+                if (row.exists()) {
+                    item_pk_values.push(pk);
+
+                    data.items.push({
+                        item: pk,
+                    });
+                }
+            });
+
+            var extra_fields = [
+                'location',
+                'notes',
+                'allow_mismatched_suppliers',
+                'allow_mismatched_status',
+            ];
+
+            extra_fields.forEach(function(field) {
+                data[field] = getFormFieldValue(field, fields[field], opts);
+            });
+
+            opts.nested = {
+                'items': item_pk_values
+            };
+
+            // Submit the form data
+            inventreePut(
+                '{% url "api-stock-merge" %}',
+                data,
+                {
+                    method: 'POST',
+                    success: function(response) {
+                        $(opts.modal).modal('hide');
+
+                        if (options.success) {
+                            options.success(response);
+                        }
+                    },
+                    error: function(xhr) {
+                        switch (xhr.status) {
+                        case 400:
+                            handleFormErrors(xhr.responseJSON, fields, opts);
+                            break;
+                        default:
+                            $(opts.modal).modal('hide');
+                            showApiError(xhr, opts.url);
+                            break;
+                        }
+                    }
+                }
+            );
+        }
+    });
+}
+
+
 /**
  * Perform stock adjustments
  */
@@ -1875,6 +2054,20 @@ function loadStockTable(table, options) {
         stockAdjustment('move');
     });
 
+    $('#multi-item-merge').click(function() {
+        var items = $(table).bootstrapTable('getSelections');
+
+        mergeStockItems(items, {
+            success: function(response) {
+                $(table).bootstrapTable('refresh');
+
+                showMessage('{% trans "Merged stock items" %}', {
+                    style: 'success',
+                });
+            }
+        });
+    });
+
     $('#multi-item-assign').click(function() {
 
         var items = $(table).bootstrapTable('getSelections');

InvenTree/templates/stock_table.html

@@ -49,6 +49,7 @@
                     <li><a class='dropdown-item' href="#" id='multi-item-remove' title='{% trans "Remove from selected stock items" %}'><span class='fas fa-minus-circle'></span> {% trans "Remove stock" %}</a></li>
                     <li><a class='dropdown-item' href="#" id='multi-item-stocktake' title='{% trans "Stocktake selected stock items" %}'><span class='fas fa-check-circle'></span> {% trans "Count stock" %}</a></li>
                     <li><a class='dropdown-item' href='#' id='multi-item-move' title='{% trans "Move selected stock items" %}'><span class='fas fa-exchange-alt'></span> {% trans "Move stock" %}</a></li>
+                    <li><a class='dropdown-item' href='#' id='multi-item-merge' title='{% trans "Merge selected stock items" %}'><span class='fas fa-object-group'></span> {% trans "Merge stock" %}</a></li>
                     <li><a class='dropdown-item' href='#' id='multi-item-order' title='{% trans "Order selected items" %}'><span class='fas fa-shopping-cart'></span> {% trans "Order stock" %}</a></li>
                     <li><a class='dropdown-item' href='#' id='multi-item-assign' title='{% trans "Assign to customer" %}'><span class='fas fa-user-tie'></span> {% trans "Assign to customer" %}</a></li>
                     <li><a class='dropdown-item' href='#' id='multi-item-set-status' title='{% trans "Change status" %}'><span class='fas fa-exclamation-circle'></span> {% trans "Change stock status" %}</a></li>