Clojure Code Review Skill

@./../_shared/clojure-style-guide.md

@./../_shared/clojure-commands.md

Review guidelines

What to flag:

• Check compliance with the Metabase Clojure style guide (included above)

• If CLOJURE_STYLE_GUIDE.adoc exists in the working directory, also check compliance with the community Clojure style guide

• Flag all style guide violations

What NOT to post:

• Do not post comments congratulating someone for trivial changes or for following style guidelines

• Do not post comments confirming things "look good" or telling them they did something correctly

• Only post comments about style violations or potential issues

Example bad code review comments to avoid:

This TODO comment is properly formatted with author and date - nice work!

Good addition of limit 1 to the query - this makes the test more efficient without changing its behavior.

The kondo ignore comment is appropriately placed here

Test name properly ends with -test as required by the style guide.

Special cases:

• Do not post comments about missing parentheses (these will be caught by the linter)

Quick review checklist

Use this to scan through changes efficiently:

Naming

• Descriptive names (no tbl, zs')

• Pure functions named as nouns describing their return value

• kebab-case for all variables and functions

• Side-effect functions end with !

• No namespace-alias repetition in function names

Documentation

• Public vars in src or enterprise/backend/src have useful docstrings

• Docstrings use Markdown conventions

• References use [[other-var]] not backticks

• TODO comments include author and date: ;; TODO (Name 2025-01-01) -- description

Code Organization

• Everything ^:private unless used elsewhere

• No declare when avoidable (public functions near end)

• Functions under 20 lines when possible

• No blank, non-comment lines within definition forms (except pairwise constructs in let/cond)

• Lines ≤ 120 characters

Tests

• Separate deftest forms for distinct test cases

• Pure tests marked ^:parallel

• Test names end in -test or -test-<number>

Modules

• Correct module patterns (OSS: metabase.<module>.*, EE: metabase-enterprise.<module>.*)

• API endpoints in <module>.api namespaces

• Public API in <module>.core with Potemkin

• No cheating module linters with :clj-kondo/ignore [:metabase/modules]

REST API

• Response schemas present (:- <schema>)

• Query params use kebab-case, bodies use snake_case

• Routes use singular nouns (e.g., /api/dashboard/:id)

• GET has no side effects (except analytics)

• Malli schemas detailed and complete

• All new endpoints have tests

MBQL

• No raw MBQL manipulation outside lib, lib-be, or query-processor modules

• Uses Lib and MBQL 5, not legacy MBQL

Database

• Model and table names are singular nouns

• Uses t2/select-one-fn instead of selecting full rows for one column

• Logic in Toucan methods, not helper functions

Drivers

• New multimethods documented in docs/developers-guide/driver-changelog.md

• Passes driver argument to other driver methods (no hardcoded driver names)

• Minimal logic in read-column-thunk

Miscellaneous

• Example data is bird-themed when possible

• Kondo linter suppressions use proper format (not #_:clj-kondo/ignore keyword form)

Pattern matching table

Quick scan for common issues:

Pattern

Issue

calculate-age, get-user

Pure functions should be nouns: age, user

update-db, save-model

Missing ! for side effects: update-db!, save-model!

snake_case_var

Should use kebab-case

Public var without docstring

Add docstring explaining purpose

;; TODO fix this

Missing author/date: ;; TODO (Name 2025-01-01) -- description

(defn foo ...) in namespace used elsewhere

Should be (defn ^:private foo ...)

Function > 20 lines

Consider breaking up into smaller functions

/api/dashboards/:id

Use singular: /api/dashboard/:id

Query params with snake_case

Use kebab-case for query params

New API endpoint without tests

Add tests for the endpoint

Feedback format examples

For style violations:

This pure function should be named as a noun describing its return value. Consider user instead of get-user.

For missing documentation:

This public var needs a docstring explaining its purpose, inputs, and outputs.

For organization issues:

This function is only used in this namespace, so it should be marked ^:private.

For API conventions:

Query parameters should use kebab-case. Change user_id to user-id.