trailofbits.go.iterate-over-empty-map.iterate-over-empty-collection

rules:
  - id: iterate-over-empty-collection
    patterns:
      - pattern: |
          $C = make(map[$T1] $T2, ...)
          ...
          for $K := range $C { ... }
      - pattern-not: |
          $C = make(map[$T1] $T2, ...)
          ...
          $C[$X] = $V
          ...
          for $K := range $C { ... }
      - pattern-not: |
          $C = make(map[$T1] $T2, ...)
          ...
          $C[$X]++
          ...
          for $K := range $C { ... }
      - pattern-not: |
          $C = make(map[$T1] $T2, ...)
          ...
          $C[$X]--
          ...
          for $K := range $C { ... }
      - pattern-not: |
          $C = make(map[$T1] $T2, ...)
          ...
          $CODEC.Unmarshal($C)
          ...
          for $K := range $C { ... }
    message: >
      Iteration over a possibly empty map `$C`. This is likely a bug or
      redundant code.
    languages:
      - go
    severity: ERROR
    metadata:
      license: CC-BY-NC-SA-4.0