# Campaign Service Code Review > How to judge the implementation of an lfx-v2-campaign-service pull request: the Go quality dimensions (correctness, concurrency, error handling, tests, performance, readability, code truthfulness), how to hold the diff to the repo's documented standards, and the security anchors for a service that brokers to paid ad platforms and stores encrypted credentials. Use on every PR that changes code, however small; this is the reviewer's line-level lens. - Skill: `linuxfoundation/campaign-service-code-review` (Agent Skill) - Install (CLI): `npx skillmds@latest add linuxfoundation/campaign-service-code-review` - Raw SKILL.md: https://api.skillmd.com/api/skills/linuxfoundation/campaign-service-code-review/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Marketing & Growth - Author: linuxfoundation (https://skillmd.com/u/linuxfoundation) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/linuxfoundation/campaign-service-code-review --- # Campaign Service Code Review Reviewer scope and the signal bar are owned by the `copilot-code-reviewer` skill (`.github/skills/copilot-code-reviewer/SKILL.md`); this skill covers only the line-level method. A diff alone is not enough: for each non-trivial hunk read the **whole changed function** plus the layers around it — for a handler, the design method and the repository call beneath; for a dispatch change, the orchestrator contract above and the platform client below — and search for **callers and sibling implementations** of the same pattern to confirm the change matches how the repo already does it. Convention drift is a finding even when the code "works", and because the per-provider packages are deliberately parallel the sibling is usually right there: a divergence is either justified in the code or a finding. ## The house standards The repo defines its own standards; hold the diff to them, and name the documented source in any standards finding. Read the parts relevant to the diff before judging, every run, because the standards belong to the repo and move with it. They live in: - **`CLAUDE.md`** — the agent guide: start from the knowledge bundle, and the knowledge-base upkeep contract. - **`README.md`** — the environment-variable contract with its defaults and required sets, the local run and Helm workflows, and the `make` targets. - **`docs/`** — `architecture.md` (the numbered architectural decisions, the persistence model, the authorization model), `api-catalog.md` (the API design rules every endpoint follows, and the endpoint catalog), and `channel-connections-schema.md` (the table definitions). - **`docs/knowledge/`** — the Open Knowledge Format bundle, with concept files covering the service's main packages and its Kubernetes resources: the fastest way to check what a package is *supposed* to do before judging the diff. Enforcement runs in both directions: code that violates a documented standard is a finding, and a documented standard the code has visibly outgrown is a finding against the docs. If a documented convention is wrong for this specific change, say so explicitly and explain the trade, rather than silently waiving or silently enforcing it. Read the rest of this skill as invariants, not as an inventory. This codebase carries deliberate, reasoned exceptions to most of its own patterns, so those sources — not this file — are the authority for the shape a given endpoint, package, or call has today. Check them before calling a deviation a defect: an exception the code justifies is not a finding; one that has quietly lost its justification is. ## Quality dimensions Run these on the changed code, scaled to the size of the change: - **Correctness and concurrency.** A context reaches every call that can block and cancellation is honored — except where the code deliberately detaches, a real pattern here for work that must finish after its caller is gone. There, and for a goroutine that outlives its request, the question is whether the work carries its own deadline and a bounded lifetime, not whether it detached. Shared state that is late-bound or swapped at runtime is accessed under the lock that guards it; fan-out across platforms is bounded; every acquired resource is released on every path — `defer` where its lifetime genuinely is the function's, an explicit release per iteration inside a loop or a retry. - **Error handling.** Errors wrapped with `%w` so sentinels survive, failures distinguished by remedy rather than collapsed. A discarded error is a finding when the caller needed it, not on sight — best-effort cleanup and parsing are deliberate here, and an error string that drops detail to avoid carrying a secret is doing its job. The domain package defines the sentinels and the service layer maps them onto the contract's typed errors; a new failure mode reaching the API needs that mapping, or it surfaces as an untyped 500 the published contract never promised. - **Tests.** New or changed behavior needs tests that assert real behavior, not that a mock was called; the repo's style is table-driven Go tests beside the code. A test that introduces shared mutable state without synchronization is a defect whether or not the suite runs under a race detector. Missing tests on a contract-bearing, concurrency-bearing, or security-sensitive path are worth flagging. - **Performance.** Unbounded result sets, a query per row where a set operation would do, an HTTP client or credential decryption rebuilt per request when it could be hoisted, and an outbound call to an ad platform with no timeout — a hung upstream must not become a hung handler. Retries are not universal: whether a call may be retried depends on the upstream operation's idempotency, which the clients decide per method, deliberately. Read the client's own retry path before calling a missing retry a defect — where a retry could double-create, suppressing it is correct and adding one is the finding. - **Readability and structure.** The change reads like the surrounding code; names say what a thing is or does; comments explain *why*; duplicated logic that wants a shared helper is a finding when it traps the next editor. - **Code truthfulness.** Comments and docs match what the code actually does. This repo leans hard on long explanatory comments, so a comment that has silently gone stale is more dangerous here than usual — one describing an invariant the diff just changed is a finding. ## Campaign service specifics worth a second look - **The generated boundary.** `design/` is where the contract is authored; everything under `gen/` is Goa output and is not hand-edited, so editing a generated file is a defect — as is a `design/` change whose regenerated output is missing from the PR, since the build regenerates before compiling and CI will not catch that drift for you. Tests that exercise generated validators belong outside the generated tree. - **Contract, schema, and docs move together.** A new or changed field usually touches the design, a paired up/down migration, the repository's column handling, and the documented schema; a missing down file, or a schema change whose docs are untouched, is worth raising. Storage and contract are deliberately *not* one-to-one, though — internal-only columns exist, and a credential column is one the API must never expose. Ask which surfaces a new column is *meant* to reach, from the documented schema and API design rules. - **Optimistic concurrency.** Rows carry a version that powers ETag and `If-Match`, with distinct statuses for a missing precondition and a stale one. That contract governs the *conditional* paths only; check the documented API design rules for the shape an endpoint is meant to have rather than assuming every mutation is conditional. A conditional path that skips the precondition, or fails to distinguish "not found" from "version mismatch", breaks a contract the callers depend on. - **Connection identity is keyed on the project.** That identifier scopes the rows and is the exact-match key the dispatch path joins on, so a change to how it is validated or normalised on any route changes which records are reachable — say so rather than treating it as a validation tweak. The uniqueness the schema enforces on it is narrower than "one row per provider, ever": read the migration that creates the constraint, which is the DDL that actually runs. The schema doc and the migrations do not currently agree on this, so treat the migration as the answer and the disagreement as a doc-drift finding in its own right — a pointer into a stale doc is how a reviewer ends up confidently wrong. - **Startup and shutdown are load-bearing.** The service supports a database cold start: it boots serving the contract's typed 503, retries in the background, and late-binds live backends without a pod restart; a migration failure a retry could never clear is deliberately not retried. The shutdown budget is arithmetic between named constants, so changing one of those timeouts is a behavior change even when the code compiles — ask whether it is stated, intentional, and bounded in blast radius. - **The probes mean different things.** Liveness is process-only and must not acquire a database dependency; readiness reflects the database when one is configured. A database-less run is supported, not broken — a change that makes readiness fail in that mode, or couples liveness to the pool, breaks how Kubernetes treats the pod. - **Configuration.** CLI flags win over environment variables, which win over defaults, and a partially supplied database configuration is rejected at startup rather than silently half-applied. The server and database settings resolve their environment-variable names through the shared constants package rather than string literals at the use site; that convention is not repo-wide, so judge a new setting against how its own package resolves configuration and against the documented environment-variable contract. - **Logging.** Structured `slog`, using the context-carrying call forms wherever a request context is in hand, so the request ID the middleware attaches lands on the line, and the plain forms where there genuinely is none. An unstructured message where fields belong, or a log line carrying a credential, a key, or a DSN, is a finding. So is printing to stdout from the service; in a command whose output *is* stdout, it is the point. - **Knowledge-base upkeep.** The agent guide asks a merged change to leave the knowledge bundle current — concept file updated, containing index bullet updated only when a concept was added, renamed, or re-described, dated change log entry appended — and expects the bundle validated rather than regenerated, because the generator overwrites hand-edited concept files. Read the guide for the contract as it stands, note a genuinely missing update, and never ask for a regeneration. ## Security anchors Hold these lines on any diff that touches them: - **Credentials are encrypted in the application, before storage.** The encryption key comes from the environment and is deliberately never given to the database. Any path that would write a credential unencrypted, return one in a response body, or put one in a log or an error message is a security defect. Responses report *whether* a connection holds credentials, not the credentials themselves — preserve that shape. Credential-shaped literals in tests are judged on whether they are real, per the repository anchor below. - **Secrets stay out of logs and out of error strings.** The config type does carry secret material — the composed database DSN, password included, and the credential encryption key — and keeps it out of formatted output by masking those fields in its own formatting methods. That holds only where it is actually reached: a new secret-bearing field the masking misses, a formatting path that sidesteps the type's own, or an error or log line interpolating a DSN or a key, defeats it. Prefer a purpose-built safe-to-log accessor over formatting the config itself. - **Secrets stay out of the repository.** No *real* credential in source, fixtures, values files, or tests. Unmistakably fake test data is expected and is never a finding on its own — the crypto round-trip and the platform client tests cannot be written without credential-shaped inputs. A sample key for local development is acceptable only while unmistakably marked non-production. - **Authorization happens at the gateway, not in this process.** Heimdall authenticates and OpenFGA authorizes on a project relation before a request arrives, so the in-process JWT handling exists to require a token's presence and extract principal claims for *attribution*. Do not let a diff turn those claims into an authorization decision or trusted identity, or make a route reachable off that path. Be careful how you cite this: the security scheme in `design/` and the handler that implements it currently describe in-process validation differently, and the repo has not settled which is intended. Treat that as an open question rather than a decided contract — a diff that deepens reliance on claims the process has not verified is a finding, and one that closes the gap is a change to the authentication boundary and should read like one. - **The chart's route and its authorization rules must stay in agreement.** They are two hand-maintained matchers over the same path set, coupled only by a parity test in the chart. Because the rule engine is default-deny, a path the route forwards but no rule authorizes becomes unreachable rather than open, and the inverse edit is dead config; either drift is a finding, so any new endpoint family needs both sides considered. - **SQL is parameterized for values, and identifiers come from fixed internal allowlists.** The repositories build per-provider statements from compile-time column and table names while binding every value as a placeholder. New query code must keep that split; an identifier assembled from anything a caller can influence is an injection finding, and a suppressed linter warning on such a line needs its justification checked, not assumed. - **Migrations are paired and run at startup.** An irreversible or unpaired migration, or one that takes a lock the startup deadline cannot absorb, is a production risk worth raising even though it will pass CI. ## Judgment calls - **Point at the working pattern.** When the diff violates a pattern, cite the sibling provider, repository, or adapter that gets it right rather than describing an abstract ideal. - **Do not propose rewrites of a sound approach**, and do not suggest change for its own sake; working, readable code needs no improvement. The repetitive per-provider shape in this repo is intentional — do not ask for it to be collapsed. - **Know your limits.** Comment only on what you can establish from the code in front of you; a judgment resting on a surface you cannot read does not clear the confidence bar in `copilot-code-reviewer`, hedged or not.