Simplify Make Slice

ID

go.simplify_make_slice

Severity

low

Remediation Complexity

trivial

Remediation Risk

low

Remediation Effort

low

Resource

Code Smell

Language

Go

Tags

CWE:1164, code-style, readability

Description

Reports a range loop that copies every element of one slice onto another with append, where a single append with a spread would do the whole job.

Rationale

dst = append(dst, src…​) concatenates two slices in one call. Spelling it out as a loop is more code, slower (no bulk growth) and obscures the intent. The rule fires only when source and destination resolve to the same slice element type and the destination is not the slice being ranged; differing element types or unresolved types are left alone.

func fn(src, dst []int) {
    for _, v := range src { // FLAW — dst = append(dst, src...)
        dst = append(dst, v)
    }
    _ = dst
}

Remediation

Replace the loop with dst = append(dst, src…​).

References