[Feature] Add RMA support (#4488)

* Adds ReturnOrder and ReturnOrderAttachment models

* Adds new 'role' specific for return orders

* Refactor total_price into a mixin

- Required for PurchaseOrder and SalesOrder
- May not be required for ReturnOrder (remains to be seen)

* Adds API endpoints for ReturnOrder

- Add list endpoint
- Add detail endpoint
- Adds required serializer models

* Adds basic "index" page for Return Order model

* Update API version

* Update navbar text

* Add db migration for new "role"

* Add ContactList and ContactDetail API endpoints

* Adds template and JS code for manipulation of contacts

- Display a table
- Create / edit / delete

* Splits order.js into multiple files

- Javascript files was becoming extremely large
- Hard to debug and find code
- Split into purchase_order / return_order / sales_order

* Fix role name (change 'returns' to 'return_order')

- Similar to existing roles for purchase_order and sales_order

* Adds detail page for ReturnOrder

* URL cleanup

- Use <int:pk> instead of complex regex

* More URL cleanup

* Add "return orders" list to company detail page

* Break JS status codes into new javascript file

- Always difficult to track down where these are rendered
- Enough to warrant their own file now

* Add ability to edit return order from detail page

* Database migrations

- Add new ReturnOrder modeles
- Add new 'contact' field to external orders

* Adds "contact" to ReturnOrder

- Implement check to ensure that the selected "contact" matches the selected "company"

* Adjust filters to limit contact options

* Fix typo

* Expose 'contact' field for PurchaseOrder model

* Render contact information

* Add "contact" for SalesOrder

* Adds setting to enable / disable return order functionality

- Simply hides the navigation elements
- API is not disabled

* Support filtering ReturnOrder by 'status'

- Refactors existing filter into the OrderFilter class

* js linting

* More JS linting

* Adds ReturnOrderReport model

* Add serializer for the ReturnOrderReport model

- A little bit of refactoring along the way

* Admin integration for new report model

* Refactoring for report.api

- Adds generic mixins for filtering queryset (based on updates to label.api)
- Reduces repeated code a *lot*

* Exposes API endpoints for ReturnOrderReport

* Adds default example report file for ReturnOrder

- Requires some more work :)

* Refactor report printing javascript code

- Replace all existing functions with 'printReports'

* Improvements for default StockItem test report template

- Fix bug in template
- Handle potential errors in template tags
- Add more helpers to report tags
- Improve test result rendering

* Reduce logging verbosity from weasyprint

* Refactor javascript for label printing

- Consolidate into a single function
- Similar to refactor of report functions

* Add report print button to return order page

* Record user reference when creating via API

* Refactor order serializers

- Move common code into AbstractOrderSerializer class

* Adds extra line item model for the return order

- Adds serializer and API endpoints as appropriate

* Render extra line table for return order

- Refactor existing functions into a single generic function
- Reduces repeated JS code a lot

* Add ability to create a new extra line item

* Adds button for creating a new lien item

* JS linting

* Update test

* Typo fix

(cherry picked from commit 28ac2be35b)

* Enable search for return order

* Don't do pricing (yet) for returnorder extra line table

- Fixes an uncaught error

* Error catching for api.js

* Updates for order models:

- Add 'target_date' field to abstract Order model
- Add IN_PROGRESS status code for return order
- Refactor 'overdue' and 'outstanding' API queries
- Refactor OVERDUE_FILTER on order models
- Refactor is_overdue on order models
- More table filters for return order model

* JS cleanup

* Create ReturnOrderLineItem model

- New type of status label
- Add TotalPriceMixin to ReturnOrder model

* Adds an API serializer for the ReturnOrderLineItem model

* Add API endpoints for ReturnOrderLineItem model

- Including some refactoring along the way

* javascript: refactor loadTableFilters function

- Pass enforced query through to the filters
- Call Object.assign() to construct a superset query
- Removes a lot of code duplication

* Refactor hard-coded URLS to use {% url %} lookup

- Forces error if the URL is wrong
- If we ever change the URL, will still work

* Implement creation of new return order line items

* Adds 'part_detail' annotation to ReturnOrderLineItem serializer

- Required for rendering part information

* javascript: refactor method for creating a group of buttons in a table

* javascript: refactor common buttons with helper functions

* Allow edit and delete of return order line items

* Add form option to automatically reload a table on success

- Pass table name to options.refreshTable

* JS linting

* Add common function for createExtraLineItem

* Refactor loading of attachment tables

- Setup drag-and-drop as part of core function

* CI fixes

* Refactoring out some more common API endpoint code

* Update migrations

* Fix permission typo

* Refactor for unit testing code

* Add unit tests for Contact model

* Tests for returnorder list API

* Annotate 'line_items' to ReturnOrder serializer

* Driving the refactor tractor

* More unit tests for the ReturnOrder API endpoints

* Refactor "print orders" button for various order tables

- Move into "setupFilterList" code (generic)

* add generic 'label printing' button to table actions buttons

* Refactor build output table

* Refactoring icon generation for js

* Refactoring for Part API

* Fix database model type for 'received_date'

* Add API endpoint to "issue" a ReturnOrder

* Improvements for stock tracking table

- Add new status codes
- Add rendering for SalesOrder
- Add rendering for ReturnOrder
- Fix status badges

* Adds functionality to receive line items against a return order

* Add endpoints for completing and cancelling orders

* Add option to allow / prevent editing of ReturnOrder after completed

* js linting

* Wrap "add extra line" button in setting check

* Updates to order/admin.py

* Remove inline admin for returnorderline model

* Updates to pass CI

* Serializer fix

* order template fixes

* Unit test fix

* Fixes for ReturnOrder.receive_line_item

* Unit testing for receiving line items against an RMA

* Improve example report for return order

* Extend unit tests for reporting

* Cleanup here and there

* Unit testing for order views

* Clear "sales_order" field when returning against ReturnOrder

* Add 'location' to deltas when returning from customer

* Bug fix for unit test

InvenTree/report/tests.py

@@ -29,6 +29,20 @@ class ReportTagTest(TestCase):
         """Enable or disable debug mode for reports"""
         InvenTreeSetting.set_setting('REPORT_DEBUG_MODE', value, change_user=None)
 
+    def test_getindex(self):
+        """Tests for the 'getindex' template tag"""
+
+        fn = report_tags.getindex
+        data = [1, 2, 3, 4, 5, 6]
+
+        # Out of bounds or invalid
+        self.assertEqual(fn(data, -1), None)
+        self.assertEqual(fn(data, 99), None)
+        self.assertEqual(fn(data, 'xx'), None)
+
+        for idx in range(len(data)):
+            self.assertEqual(fn(data, idx), data[idx])
+
     def test_getkey(self):
         """Tests for the 'getkey' template tag"""
 
@@ -419,7 +433,7 @@ class BOMReportTest(ReportTest):
 
 
 class PurchaseOrderReportTest(ReportTest):
-    """Unit test class fort he PurchaseOrderReport model"""
+    """Unit test class for the PurchaseOrderReport model"""
     model = report_models.PurchaseOrderReport
 
     list_url = 'api-po-report-list'
@@ -446,3 +460,18 @@ class SalesOrderReportTest(ReportTest):
         self.copyReportTemplate('inventree_so_report.html', 'sales order report')
 
         return super().setUp()
+
+
+class ReturnOrderReportTest(ReportTest):
+    """Unit tests for the ReturnOrderReport model"""
+
+    model = report_models.ReturnOrderReport
+    list_url = 'api-return-order-report-list'
+    detail_url = 'api-return-order-report-detail'
+    print_url = 'api-return-order-report-print'
+
+    def setUp(self):
+        """Setup function for the ReturnOrderReport tests"""
+        self.copyReportTemplate('inventree_return_order_report.html', 'return order report')
+
+        return super().setUp()