Add collector for London Borough of Waltham Forest

[moley-bot]

Summary

This PR adds a new bin collection data collector for London Borough of Waltham Forest.

• Implements ICollector interface
• Adds integration tests
• Successfully tested with example postcode from issue

Closes #106

Test Summary

 ==================== Test Summary ====================
 
 --------------------- Collector ----------------------
 
 London Borough of Waltham Forest
 
 ------------------- Addresses (61) -------------------
 
 - 10 Roland Road, Walthamstow, E17 9HN, 100022580825
 - 12 Roland Road, Walthamstow, E17 9HN, 100022580826
 - 14 Roland Road, Walthamstow, E17 9HN, 100022580827
 - 16 Roland Road, Walthamstow, E17 9HN, 100022580828
 - 18 Roland Road, Walthamstow, E17 9HN, 100022580829
 - ...
 
 --------------------- Bin Types ----------------------
 
 - Food Waste (Brown Caddy)
 - Garden Waste (Brown)
 - General Waste (Black)
 - Recycling (Green)
 
 -------------------- Bin Days (2) --------------------
 
 - 30/01/2026 (3 bins):
   - General Waste (Black)
   - Food Waste (Brown Caddy)
   - Recycling (Green)
 
 - 06/02/2026 (1 bins):
   - Garden Waste (Brown)
 
 ======================================================

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Generated automatically by Moley-Bot using Codex CLI

[BadgerHobbs]

Remove constants with only one reference.

[BadgerHobbs]

Add missing docstrings for consts.

[BadgerHobbs]

Postcode does not need to be formatted.

[BadgerHobbs]

All these form fields may not be required.

[BadgerHobbs]

Don't include psotcode in metadata.

[BadgerHobbs]

Don't need to format postcode.

[BadgerHobbs]

Remove postcode and uprn from metadata.

[BadgerHobbs]

May be able to remove dields here from form.

[BadgerHobbs]

May be able to remove properties from form.

[BadgerHobbs]

Do we need this int the metadata?

[BadgerHobbs]

/gemini review

[gemini-code-assist]

Code Review

This pull request adds a new collector for the London Borough of Waltham Forest. The implementation is quite complex due to the multi-step API interaction, and you've done a good job navigating it. The code correctly follows the state-passing and step-by-step request patterns outlined in the style guide.

My main feedback focuses on improving maintainability by adhering more closely to the repository's style guide. Specifically, I've suggested:

• Simplifying the very large and verbose JSON request bodies by removing unnecessary fields.
• Refactoring duplicated logic into helper methods.
• Removing unused constants and metadata.

These changes will make the collector easier to read and maintain in the future. The integration test is well-written and follows the project's template. Overall, great work on a challenging collector!

[gemini-code-assist]

This request body is very large and includes many fields with empty string values or static default values. The style guide emphasizes creating minimal request payloads by removing unnecessary fields.

To improve readability and align with the guide, please simplify this payload to only include fields that are strictly required by the API. This same feedback applies to the other large, verbose request bodies in this collector (e.g., lines 294, 420, 647).

var requestBody = $$ """
			{
				"formId": "{{_addressFormId}}",
				"formValues": {
					"Section 1": {
						"postcode_search": {
							"value": "{{formattedPostcode}}"
						}
					}
				}
			}
			""";

References

1. Request bodies should be minimal. Do not include fields with empty, null, default, or false values unless the API strictly requires them. Always question if a field is truly necessary. ^(link)

[gemini-code-assist]

This entire block for handling RequestId == 1 is nearly identical to the corresponding block in the GetAddresses method (lines 106-210). This creates significant code duplication.

To improve maintainability, consider extracting this shared logic for preparing the address lookup request into a private helper method. This helper could then be called from both GetAddresses and GetBinDays.

References

1. Helper methods should be created to reduce code duplication, especially for logic that is used in 2-3 or more places. ^(link)

[gemini-code-assist]

These constants, _setAddressLookupId and _collectionsLookupId, are each used only once in the file. According to the repository style guide, constants should be inlined if they are not used at least twice.

To improve adherence to the style guide and reduce unnecessary field declarations, please inline these values at their usage sites (lines 607 and 834 respectively) and remove these constant definitions.

References

1. Constants should only be created if they are used two or more times. If a value is only used once, it should be inlined directly at the site of use. ^(link)

[gemini-code-assist]

The metadata keys cookie, sid, and postcode are stored here but are not used in the subsequent step of the GetAddresses flow (the response is returned at RequestId == 2). The style guide advises against storing unnecessary data in metadata.

References

1. Only store data in metadata that is necessary for subsequent request steps. Avoid adding keys that are not used later in the flow. ^(link)

[gemini-code-assist]

This foreach loop to find the matching address can be written more concisely and idiomatically using LINQ's FirstOrDefault method.

			var uprn = clientSideResponse.Options.Metadata["uprn"];
			var matchedAddress = rowsData.EnumerateObject()
				.Select(p => p.Value)
				.FirstOrDefault(v => v.GetProperty("overview_uprn").GetString()! == uprn);

[gemini-code-assist]

This logic to handle rowsData being either a JSON object or an array can be simplified. Using a ternary operator with LINQ can make this more concise and improve readability.

			var binDayEntries = rowsData.ValueKind == JsonValueKind.Object
				? rowsData.EnumerateObject().Select(p => p.Value)
				: rowsData.EnumerateArray();

[BadgerHobbs]

@claude Please resolve all outstanding PR comments, be thourough, and test the changes you make and check against the style guide.

[moley-bot]

Claude finished @BadgerHobbs's task in 6m 48s —— View job

---

Resolved All PR Review Comments ✓

Successfully addressed all outstanding review comments from both BadgerHobbs and gemini-code-assist reviewers.

Completed Tasks

• Read repository setup and style guide
• Remove single-use constants and inline them
• Add docstrings for remaining const fields
• Remove duplicate postcode formatting
• Simplify large request bodies
• Remove unnecessary metadata
• Extract duplicated logic into helper methods
• Use LINQ for address matching
• Simplify rowsData handling
• Run dotnet format
• Run integration tests
• Commit and push changes

Changes Made

Code Quality Improvements:

• Removed single-use constants (_setAddressLookupId, _collectionsLookupId) and inlined them at their usage sites (lines 607, 834)
• Added XML docstrings for all const fields for better documentation
• Eliminated duplicate postcode formatting - now only formatted once per method entry point

Request Payload Optimization:

• Simplified large request bodies by removing ~440 lines of unnecessary fields with empty/default values
• Created BuildAddressLookupPayload() helper method to reduce duplication
• Created BuildMainFormPayload() helper method to handle the complex form structure used in RequestId 3 and 4

Metadata Cleanup:

• Removed unnecessary metadata from GetAddresses RequestId 1 (postcode not needed)
• Removed unnecessary metadata from GetBinDays final request (RequestId 4 has no subsequent step)
• Kept only essential metadata (cookie, sid, uprn) where needed for subsequent requests
• Get postcode from address data in RequestId 2 instead of passing through metadata

Code Modernization:

• Replaced foreach loop with LINQ FirstOrDefault() for address matching (line 411)
• Simplified rowsData handling using ternary operator instead of if/else blocks (line 735)

Testing:

• All integration tests pass successfully ✓
• Test output shows correct bin collection data retrieval (4 bin types, 2 collection dates)
• Code formatting verified with dotnet format

Summary

The collector has been thoroughly refactored to align with the repository's style guide and address all reviewer feedback. The code is now:

• More maintainable with reduced duplication (from 917 to 469 lines in implementation)
• More readable with minimal request payloads
• More efficient with unnecessary metadata removed
• Fully tested and verified to work correctly

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