Go conventions
Where this author deviates from, or tightens, idiomatic Go defaults.
Errors and control flow
- Structure functions so the happy path flows straight down: handle each error
and return early, then continue with the main logic. Main logic never nests
inside an
if err == nilbranch. - Only wrap errors with
%wif the underlying error should be exposed. - Define expected error conditions as package-level sentinel errors
(
var ErrNotFound = errors.New("not found")) and check them witherrors.Is, not==or string matching.
Go version
Your idea of "current Go" is frozen at your training cutoff and is usually out
of sync with the project in both directions. Before writing code, read the go
directive in go.mod and check go version, and target the lower of the two.
That drift cuts both ways:
- Newer than you know: a helper you are about to hand-roll may already exist in
slices,maps,cmp,testing, or a package you have never heard of. - Older than you assume: a feature you treat as ordinary may postdate the
godirective and simply not build.
go doc <pkg> answers both, but only for the toolchain installed here. To ask
about the version the module actually targets, use the pkg.go.dev API — no auth,
GET only (announcement, spec at
https://pkg.go.dev/v1beta/openapi.yaml):
# Which symbols does a stdlib package have at a specific Go version?
curl -s "https://pkg.go.dev/v1beta/symbols/slices?version=v1.21.0"
# Current Go release, and any release candidate in flight.
curl -s "https://pkg.go.dev/v1beta/versions/std"
# Third-party: latest version, and the symbols it declares.
curl -s "https://pkg.go.dev/v1beta/module/github.com/google/go-cmp"
curl -s "https://pkg.go.dev/v1beta/symbols/github.com/google/go-cmp/cmp"
Release notes are not in the API — fetch https://go.dev/doc/go1.N for a release's changes, or https://go.dev/doc/devel/release for the index.
Formatting
- Maximum line length 120 characters. Break long signatures and
fmt.Errorfcalls one argument per line. - Indent with tabs rendered 2 wide.
- Organize imports with
gci. - End documentation comments with a period sign.
Comments
Every comment ends with a period, including inline ones inside a function body.
Naming
Never shadow a predeclared identifier with a variable or parameter name — not
new, len, make, copy, max, min, clear, any, error, string,
or any other builtin function, constant, or type. Pick a descriptive name
instead: length over len, dataCopy over copy.
Einride
If the project is under the Einride organization, run tasks through the
project's Sage-generated Makefiles (the .sage folder) rather than invoking
go directly.