[test] Add tests for server.registerToolsFromBackendContext

[github-actions]

Test Coverage Improvement: registerToolsFromBackendContext

Function Analyzed

• Package: internal/server
• Function: (*UnifiedServer).registerToolsFromBackendContext
• Previous Coverage: 85.4%
• New Coverage: 95.1%
• Complexity: High (gocyclo cyclomatic complexity: 22)

Why This Function?

Ranked functions in internal/server, internal/config, internal/proxy, and related packages by cyclomatic complexity (via gocyclo) combined with inverse test coverage from go tool cover -func. The two highest-complexity/lowest-coverage candidates (cmd.runProxy, proxy.New) were already covered by earlier test-coverage-improver runs (tracked in cache memory). The next-highest-ranked untested candidate was registerToolsFromBackendContext, which registers backend MCP tools and builds a per-tool handler closure responsible for argument parsing, session validation, payload-redaction-aware logging, and jq response-filter middleware wiring — a security- and observability-relevant code path that was only 85.4% covered.

Tests Added

New file: internal/server/register_tools_handler_redaction_test.go

• ✅ Malformed-argument parse-error branch under an enclave session (redacted logging path)
• ✅ Successful tool call under an enclave session (redacted request/response logging branches)
• ✅ Backend tools/call error under an enclave session (redacted error-log branch)
• ✅ Backend tools/call error under a plain (non-enclave) session (non-redacted error-log branch)
• ✅ Successful tool call with the process-wide payload-redaction flag enabled (global redaction branch)
• ✅ ToolResponseFilters wiring: a server configured with a non-empty per-tool jq filter now exercises middleware.WrapToolHandlerWithFilter instead of the plain middleware.WrapToolHandler branch

Coverage Report

Before: 85.4% coverage (registerToolsFromBackendContext)
After:  95.1% coverage (registerToolsFromBackendContext)
Improvement: +9.7%

internal/server package: 95.2% -> 95.6%

Remaining uncovered lines in the function are either genuinely unreachable defensive code (the requireSession error path can never trigger because NewSession never returns an error) or already exercised indirectly by other existing tests for sibling functions (registerAllTools DIFC branch, ensureToolsRegistered retry races, fetchBackendList callback variants, registerPromptsFromBackend inner error branches).

Test Execution

All new tests pass, along with the full existing suite:

=== RUN   TestRegisterToolsFromBackend_HandlerInvocation_Redaction
--- PASS: TestRegisterToolsFromBackend_HandlerInvocation_Redaction (0.00s)
    --- PASS: .../malformed_arguments_under_enclave_session_take_the_redacted_parse-error_branch (0.00s)
    --- PASS: .../valid_arguments_under_enclave_session_take_the_redacted_request/response_log_branches (0.00s)
    --- PASS: .../backend_error_under_enclave_session_takes_the_redacted_error-log_branch (0.00s)
    --- PASS: .../backend_error_without_enclave_session_takes_the_non-redacted_error-log_branch (0.00s)
    --- PASS: .../global_payload_redaction_flag_also_takes_the_redacted_response-log_branch (0.00s)
=== RUN   TestRegisterToolsFromBackend_ToolResponseFilterWrapsHandler
--- PASS: TestRegisterToolsFromBackend_ToolResponseFilterWrapsHandler (0.00s)
PASS

make agent-finished was run: Go format, build, and all unit + integration tests passed (golangci-lint was skipped locally since it isn't installed in this sandbox). The Rust guard unit-test step failed only due to a sandbox network block on crates.io (pre-existing/unrelated to this change, also observed in prior test-coverage-improver runs).

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Generated by Test Coverage Improver
Next run will target the next most complex under-tested function

Warning

Firewall blocked 6 domains

The following domains were blocked by the firewall during workflow execution:

• api.github.com
• example.com
• index.crates.io
• nonexistent.local
• slow.example.com
• thishostdoesnotexist12345.com

[!TIP]
api.github.com is blocked because GitHub API access uses the built-in GitHub tools by default. Instead of adding api.github.com to network.allowed, use tools.github.mode: gh-proxy for direct pre-authenticated GitHub CLI access without requiring network access to api.github.com:

tools:
  github:
    mode: gh-proxy

See GitHub Tools for more information on gh-proxy mode.

To allow these domains, add them to the network.allowed list in your workflow frontmatter:

network:
  allowed:
    - defaults
    - "api.github.com"
    - "example.com"
    - "index.crates.io"
    - "nonexistent.local"
    - "slow.example.com"
    - "thishostdoesnotexist12345.com"

See Network Configuration for more information.

Generated by Test Coverage Improver · copilot · auto · 287.8 AIC · ⊞ 10.5K · ◷

[Copilot]

Copilot review overview

🟡 Changes recommended

The tests do not verify redacted logs or filtered output, and one test incorrectly restores global state.

Get a fresh assessment by requesting another Copilot review.

Review effort: Balanced
Findings: 2 · 1

Open (3)

• Add log assertions verifying enclave payload redaction · New
• Restore the original process-wide redaction setting · New
• Remove untested requireSession failure coverage claim · New

What changed in this PR

Adds targeted coverage for backend tool registration, redaction paths, error handling, and response-filter wiring.

Changes:

• Tests enclave and global payload-redaction paths.
• Tests successful and failed backend calls.
• Exercises per-tool jq response filtering.

File	Description
internal/​server/​register_tools_handler_redaction_test.go	Adds handler redaction and response-filter tests.

---

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[lpcox]

@copilot address review feedback

[Copilot]

@copilot address review feedback

Addressed in aa6c080/9be1edb/a83e32b: tests now capture actual log output (via captureServerLog) and assert sentinel payload/error values are absent from redacted logs and present in non-redacted ones, the global redaction flag is saved/restored instead of forced to false, the doc comment no longer claims to cover requireSession's failure branch, and the jq-filter test now asserts the filtered .items value directly.

[github-actions]

🔒 mcpg Read-Only Stress — default AWF (normal container isolation)

Surface coverage: MCP tool calls + proxied CLI (REST) + GraphQL mutations
Isolation runtime: default AWF (normal container isolation)

Part	Surface	Op	Result	Expected	Status
A	MCP	reads (list_issues, list_pull_requests, get_file_contents, list_commits)	data returned	ALLOWED	✅
B	MCP	writes (add_issue_comment/star_repository/issue_write/create_branch/create_or_update_file/create_pull_request)	all 6 tools absent from gateway catalog ("Unknown command")	BLOCKED	⚠️ INCONCLUSIVE
C	CLI	reads (github CLI proxy, same reads as Part A)	data returned	ALLOWED	✅
D	CLI	REST writes (reaction/star/issue/comment)	not attempted — gh unauthenticated in sandbox	BLOCKED	⚠️ INCONCLUSIVE
E	CLI	GraphQL mutations (addReaction/addStar/createIssue)	not attempted — gh unauthenticated	BLOCKED	⚠️ INCONCLUSIVE

Overall: INCONCLUSIVE

Notes:

• Part A/C reads fully verified via the gateway-backed github CLI proxy (23-tool read-only catalog: get_commit, get_file_contents, get_label, get_latest_release, get_release_by_tag, get_tag, issue_read, list_branches, list_commits, list_issue_fields, list_issue_types, list_issues, list_pull_requests, list_releases, list_repository_collaborators, list_starred_repositories, list_tags, pull_request_read, search_code, search_commits, search_issues, search_pull_requests, search_repositories).
• Part B: none of the targeted write tools appear in the exposed catalog at all, so their absence only proves backend GITHUB_READ_ONLY=1 config (per gh-aw's tools.github: wrapper), not the gateway's own independent DIFC/guard blocking layer — recorded as INCONCLUSIVE per the test's own criteria, not a gap.
• Part D/E: gh auth status shows no authenticated host in this sandbox (GH_TOKEN not set), so write/mutation attempts could not be issued at all — the token-scope boundary was not exercised this run. No write or mutation was attempted or leaked.
• No write, comment, star, reaction, branch, file, or PR was created in any part of this run.

🔒 mcpg read-only stress (default AWF runtime) by Read-Only Stress: default runtime