Ineffective Sort

ID

go.ineffective_sort

Severity

low

Remediation Complexity

trivial

Remediation Risk

low

Remediation Effort

low

Resource

Code Smell

Language

Go

Tags

code-style, suspicious

Description

Reports an assignment of the form x = sort.XSlice(x) — with sort.StringSlice, sort.IntSlice or sort.Float64Slice — that re-assigns a slice to itself through one of the sort package’s view types.

Rationale

sort.StringSlice, sort.IntSlice and sort.Float64Slice are types, not functions, so sort.IntSlice(x) is a type conversion that produces a new value of the named slice type without sorting anything. Assigning it straight back to x therefore sorts nothing — the author almost certainly meant to sort x. The in-place helpers (sort.Ints, sort.Strings, sort.Float64s) sort the slice directly; calling the view’s own Sort method (sort.IntSlice(x).Sort()) or using sort.Sort(sort.IntSlice(x)) also sorts in place and is not reported. When x is already declared as the matching view type the conversion is a harmless no-op rather than the sort-nothing mistake, so that case is left alone.

// Bad
a = sort.StringSlice(a)        // FLAW — conversion, sorts nothing

// Good
sort.Strings(a)                // OK — direct in-place helper
sort.IntSlice(xs).Sort()       // OK — the view's Sort method sorts in place
sort.Sort(sort.StringSlice(a)) // OK — sort.Sort sorts via the view

Remediation

Use the dedicated in-place helper (sort.Ints, sort.Strings, sort.Float64s), or sort the slice through the view with sort.Sort(sort.XSlice(x)) or sort.XSlice(x).Sort().

References