CRT-A0004 · Empty string test can be improved

concourse / concourse

Active

Empty string test can be improved CRT-A0004

Anti-pattern

Major

4 months ago — 4 years old

replace len(value) == 0 with value == ""

 48			labelSet[chunkKey] = value[:valueLen]
 49			value = value[valueLen:]
 50
 51			if len(value) == 0 { 52				break
 53			}
 54

replace len(token) == 0 with token == ""

fly/commands/login.go

295		}
296		tokenBytes, err := pty.ReadLine(os.Stdin)
297		token := strings.TrimSpace(string(tokenBytes))
298		if len(token) == 0 && err == io.EOF {299			return
300		}
301		if err != nil && err != io.EOF {

replace len(w.GardenAddr) == 0 with w.GardenAddr == ""

atc/worker.go

66		return ErrInvalidWorkerVersion
67	}
68
69	if len(w.GardenAddr) == 0 {70		return ErrMissingWorkerGardenAddress
71	}
72

replace len(row.BuildStatus) != 0 with row.BuildStatus != ""

atc/scheduler/algorithm/table_helpers_test.go

815	}
816
817	buildStatus := "succeeded"
818	if len(row.BuildStatus) != 0 {819		buildStatus = row.BuildStatus
820	}
821

replace len(input.Version.Pinned) != 0 with input.Version.Pinned != ""

atc/scheduler/algorithm/table_helpers_test.go

170			JobID:           setup.jobIDs.ID(CurrentJobName),
171		}
172
173		if len(input.Version.Pinned) != 0 {174			inputConfigs[i].PinnedVersion = atc.Version{"ver": input.Version.Pinned}
175
176			setup.insertPinned(setup.resourceIDs.ID(input.Resource), atc.Version{"ver": input.Version.Pinned})

Description

It is not recommended to use len for empty string test.

A string can be tested for its emptiness either by treating it as a slice and calculating the length of the slice, or by treating it as a string and directly comparing the value. While both produce identical code when compiled, it makes more sense to treat a string as itself, than a slice, for the sake of comparison of values.

Bad practice

len(s) == 0

concourse / concourse

Bad practice

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