golang-naming

Community default. A company skill that explicitly supersedes samber/cc-skills-golang@golang-naming skill takes precedence.

Go Naming Conventions

Go favors short, readable names. Capitalization controls visibility — uppercase is exported, lowercase is unexported. All identifiers MUST use MixedCaps, NEVER underscores.

"Clear is better than clever." — Go Proverbs

"Design the architecture, name the components, document the details." — Go Proverbs

To ignore a rule, just add a comment to the code.

Quick Reference

Element	Convention	Example
Package	lowercase, single word, _test suffix OK for test files	json, http, tabwriter, http_test
File	lowercase, underscores OK	user_handler.go
Exported name	UpperCamelCase	ReadAll, HTTPClient
Unexported	lowerCamelCase	parseToken, userCount
Interface	method name + -er	Reader, Closer, Stringer
Struct	MixedCaps noun	Request, FileHeader
Constant	MixedCaps (not ALL_CAPS)	MaxRetries, defaultTimeout
Receiver	1-2 letter abbreviation	func (s *Server), func (b *Buffer)
Error variable	Err prefix	ErrNotFound, ErrTimeout
Error type	Error suffix	PathError, SyntaxError
Constructor	New (single type) or NewTypeName (multi-type)	ring.New, http.NewRequest
Boolean field	is, has, can prefix on fields and methods	isReady, IsConnected()
Test function	Test + function name	TestParseToken
Acronym	all caps or all lower	URL, HTTPServer, xmlParser
Variant: context	WithContext suffix	FetchWithContext, QueryContext
Variant: in-place	In suffix	SortIn(), ReverseIn()
Variant: error	Must prefix	MustParse(), MustLoadConfig()
Option func	With + field name	WithPort(), WithLogger()
Enum (iota)	type name prefix, zero-value = unknown	StatusUnknown at 0, StatusReady
Named return	descriptive, for docs only	(n int, err error)
Error string	lowercase (incl. acronyms), no punctuation	"image: unknown format", "invalid id"
Import alias	short, only on collision	mrand "math/rand", pb "app/proto"
Format func	f suffix	Errorf, Wrapf, Logf
Test table fields	got/expected prefixes	input string, expected int

MixedCaps

All Go identifiers MUST use MixedCaps (or mixedCaps). NEVER use underscores in identifiers — the only exceptions are test function subcases (TestFoo_InvalidInput), generated code, and OS/cgo interop. This is load-bearing, not cosmetic — Go's export mechanism relies on capitalization, and tooling assumes MixedCaps throughout.

// ✓ Good
MaxPacketSize
userCount
parseHTTPResponse

// ✗ Bad — these conventions conflict with Go's export mechanism and tooling expectations
MAX_PACKET_SIZE   // C/Python style
max_packet_size   // snake_case
kMaxBufferSize    // Hungarian notation

Avoid Stuttering

Go call sites always include the package name, so repeating it in the identifier wastes the reader's time — http.HTTPClient forces parsing "HTTP" twice. A name MUST NOT repeat information already present in the package name, type name, or surrounding context.

// Good — clean at the call site
http.Client       // not http.HTTPClient
json.Decoder      // not json.JSONDecoder
user.New()        // not user.NewUser()
config.Parse()    // not config.ParseConfig()

// In package sqldb:
type Connection struct{}  // not DBConnection — "db" is already in the package name

// Anti-stutter applies to ALL exported types, not just the primary struct:
// In package dbpool:
type Pool struct{}        // not DBPool
type Status struct{}      // not PoolStatus — callers write dbpool.Status
type Option func(*Pool)   // not PoolOption

Frequently Missed Conventions

These conventions are correct but non-obvious — they are the most common source of naming mistakes:

Constructor naming: When a package exports a single primary type, the constructor is New(), not NewTypeName(). This avoids stuttering — callers write apiclient.New() not apiclient.NewClient(). Use NewTypeName() only when a package has multiple constructible types (like http.NewRequest, http.NewServeMux).

Boolean struct fields: Unexported boolean fields MUST use is/has/can prefix — isConnected, hasPermission, not bare connected or permission. The exported getter keeps the prefix: IsConnected() bool. This reads naturally as a question and distinguishes booleans from other types.

Error strings are fully lowercase — including acronyms. Write "invalid message id" not "invalid message ID", because error strings are often concatenated with other context (fmt.Errorf("parsing token: %w", err)) and mixed case looks wrong mid-sentence. Sentinel errors should include the package name as prefix: errors.New("apiclient: not found").

Enum zero values: Always place an explicit Unknown/Invalid sentinel at iota position 0. A var s Status silently becomes 0 — if that maps to a real state like StatusReady, code can behave as if a status was deliberately chosen when it wasn't.

Subtest names: Table-driven test case names in t.Run() should be fully lowercase descriptive phrases: "valid id", "empty input" — not "valid ID" or "Valid Input".

Detailed Categories

For complete rules, examples, and rationale, see:

• Packages, Files & Import Aliasing — Package naming (single word, lowercase, no plurals), file naming conventions, import alias patterns (only use on collision to avoid cognitive load), and directory structure.

• Variables, Booleans, Receivers & Acronyms — Scope-based naming (length matches scope: i for 3-line loops, longer names for package-level), single-letter receiver conventions (s for Server), acronym casing (URL not Url, HTTPServer not HttpServer), and boolean naming patterns (isReady, hasPrefix).

• Functions, Methods & Options — Getter/setter patterns (Go omits Get so user.Name() reads naturally), constructor conventions (New or NewTypeName), named returns (for documentation only), format function suffixes (Errorf, Wrapf), and functional options (WithPort, WithLogger).

• Types, Constants & Errors — Interface naming (Reader, Closer suffix with -er), struct naming (nouns, MixedCaps), constants (MixedCaps, not ALL_CAPS), enums (type name prefix like StatusReady), sentinel errors (ErrNotFound variables), error types (PathError suffix), and error message conventions (lowercase, no punctuation).

• Test Naming — Test function naming (TestFunctionName), table-driven test field conventions (input, expected), test helper naming, and subcase naming patterns.

Common Mistakes

Mistake	Fix
ALL_CAPS constants	Go reserves casing for visibility, not emphasis — use MixedCaps (MaxRetries)
GetName() getter	Go omits Get because user.Name() reads naturally at call sites. But Is/Has/Can prefixes are kept for boolean predicates: IsHealthy() bool not Healthy() bool
Url, Http, Json acronyms	Mixed-case acronyms create ambiguity (HttpsUrl — is it Https+Url?). Use all caps or all lower
this or self receiver	Go methods are called frequently — use 1-2 letter abbreviation (s for Server) to reduce visual noise
util, helper packages	These names say nothing about content — use specific names that describe the abstraction
http.HTTPClient stuttering	Package name is always present at call site — http.Client avoids reading "HTTP" twice
user.NewUser() constructor	Single primary type uses New() — user.New() avoids repeating the type name
connected bool field	Bare adjective is ambiguous — use isConnected so the field reads as a true/false question
"invalid message ID" error	Error strings must be fully lowercase including acronyms — "invalid message id"
StatusReady at iota 0	Zero value should be a sentinel — StatusUnknown at 0 catches uninitialized values
"not found" error string	Sentinel errors should include the package name — "mypackage: not found" identifies the origin
userSlice type-in-name	Types encode implementation detail — users describes what it holds, not how
Inconsistent receiver names	Switching names across methods of the same type confuses readers — use one name consistently
snake_case identifiers	Underscores conflict with Go's MixedCaps convention and tooling expectations — use mixedCaps
Long names for short scopes	Name length should match scope — i is fine for a 3-line loop, userIndex is noise
Naming constants by value	Values change, roles don't — DefaultPort survives a port change, Port8080 doesn't
FetchCtx() context variant	WithContext is the standard Go suffix — FetchWithContext() is instantly recognizable
sort() in-place but no In	Readers assume functions return new values. SortIn() signals mutation
parse() panicking on error	MustParse() warns callers that failure panics — surprises belong in the name
Mixing With*, Set*, Use*	Consistency across the codebase — With* is the Go convention for functional options
Plural package names	Go convention is singular (net/url not net/urls) — keeps import paths consistent
Wrapf without f suffix	The f suffix signals format-string semantics — Wrapf, Errorf tell callers to pass format args
Unnecessary import aliases	Aliases add cognitive load. Only alias on collision — mrand "math/rand"
Inconsistent concept names	Using user/account/person for the same concept forces readers to track synonyms — pick one name

Enforce with Linters

Many naming convention issues are caught automatically by linters: revive, predeclared, misspell, errname. See samber/cc-skills-golang@golang-lint skill for configuration and usage.

Cross-References

• → See samber/cc-skills-golang@golang-code-style skill for broader formatting and style decisions
• → See samber/cc-skills-golang@golang-structs-interfaces skill for interface naming depth and receiver design
• → See samber/cc-skills-golang@golang-lint skill for automated enforcement (revive, predeclared, misspell, errname)