refactor: inject deps via context instead of closures

[SamMorrowDrums]

Summary

This refactor changes how dependencies are passed to tool handlers from a closure-based pattern to a context-based pattern. This eliminates the need to create new closures for every tool on each request, which is critical for the remote server where one server instance is created per request.

Problem

In the closure-based pattern, NewTool stored a function that took deps and returned a handler:

// Old pattern - creates closure on every call to Handler(deps)funcNewTool(..., handlerfunc(deps) handlerFn) {
returnServerTool{
Handler: func(depsany) handlerFn {
returnhandler(deps.(ToolDependencies)) // Creates new closure each time
}
}
}

For the remote server with ~89 tools, this meant 178 allocations per request just for tool handler setup.

Solution

The new pattern injects dependencies into the context once, and handlers extract them:

// New pattern - no closure creation at request timefuncNewTool(..., handlerfunc(ctx, deps, req, args) result) {
returnServerTool{
Handler: func(ctxany) handlerFn {
returnfunc(ctx, req) result {
deps:=MustDepsFromContext(ctx) // Extract from contextreturnhandler(ctx, deps, req, args)
}
}
}
}

Benchmark Results

Throughput (89 tools, 5s benchmark, 3 runs)

Benchmark	main (old)	new	Speedup
Sequential	9,345 ns/op	4,250 ns/op	2.2x faster
Parallel	2,751 ns/op	779 ns/op	3.5x faster

Memory

Metric	main	new	Reduction
Bytes/op	7,832 B	2,136 B	73% less
Allocs/op	178	89	50% fewer

Scaling (tools from 13 to 1,300)

Tools	main	new	Speedup	Memory Saved
13	1,261 ns	811 ns	1.6x	54%
65	6,420 ns	3,771 ns	1.7x	54%
130	14,653 ns	7,797 ns	1.9x	54%
650	68,722 ns	38,872 ns	1.8x	54%
1,300	145,135 ns	67,292 ns	2.2x	54%

Changes

New APIs in pkg/github/dependencies.go

• ContextWithDeps(ctx, deps) - inject dependencies into context
• DepsFromContext(ctx) - extract dependencies (returns nil if not present)
• MustDepsFromContext(ctx) - extract dependencies (panics if not present)

Updated in pkg/inventory/server_tool.go

• NewServerToolWithContextHandler - new constructor for context-based handlers
• NewServerToolWithRawContextHandler - new constructor for raw handlers
• Old constructors marked as deprecated

Converted (89 tool handlers across 15 files)

All tool handlers converted from closure pattern to direct context-based pattern.

Test updates (17 test files)

All tests updated to use ContextWithDeps(context.Background(), deps).

Backwards Compatibility

• Old NewServerTool and NewServerToolFromHandler are deprecated but still work
• dynamic_tools.go intentionally uses the old pattern (with nolint comment) since it wraps user-provided handlers

Testing

• All existing tests pass
• script/lint passes
• script/test passes

[Copilot]

Pull request overview

This PR refactors dependency injection from a closure-based pattern to a context-based pattern, improving performance for the remote server by eliminating the need to create closures for each tool on every request. The change reduces allocations from 178 to 89 per request and achieves 2-3.5x throughput improvements.

Key changes:

• Introduces new context-based constructors (NewServerToolWithContextHandler, NewServerToolWithRawContextHandler) that avoid closure creation at registration time
• Changes handler signature from func(deps) handler to func(ctx, deps, req, args) result
• Adds context helper functions ContextWithDeps, DepsFromContext, and MustDepsFromContext in pkg/github/dependencies.go
• Converts all 89 tool handlers across 15 files to use the new pattern
• Updates all test files to inject dependencies via context

Reviewed changes

Copilot reviewed 35 out of 35 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
pkg/inventory/server_tool.go	Adds new context-based constructors; deprecates old closure-based constructors
pkg/github/security_advisories.go	Converts 4 tool handlers from closure to context pattern
pkg/github/security_advisories_test.go	Updates tests to use ContextWithDeps
pkg/github/secret_scanning.go	Converts 2 tool handlers to context pattern
pkg/github/secret_scanning_test.go	Updates tests to use ContextWithDeps
pkg/github/search.go	Converts 4 search tool handlers to context pattern, including helper function refactoring
pkg/github/search_test.go	Updates 5 test cases to use ContextWithDeps
pkg/github/repositories.go	Converts 18 repository tool handlers to context pattern
pkg/github/repositories_test.go	Updates 17 test cases to use ContextWithDeps
pkg/github/pullrequests.go	Converts 10 PR tool handlers to context pattern
pkg/github/pullrequests_test.go	Updates 18 test cases to use ContextWithDeps
pkg/github/projects.go	Converts 8 project tool handlers to context pattern
pkg/github/projects_test.go	Updates 8 test cases to use ContextWithDeps
pkg/github/notifications_test.go	Updates 6 test cases to use ContextWithDeps
pkg/github/labels.go	Converts 3 label tool handlers to context pattern
pkg/github/labels_test.go	Updates 3 test cases to use ContextWithDeps

The refactoring is comprehensive, consistent, and well-executed. All handler conversions follow the same pattern, tests are properly updated, and the deprecated constructors remain for backward compatibility. No issues were identified during the review.