.config/coc/extensions/coc-go-data/tools/pkg/mod/honnef.co/go/tools@v0.0.1-2020.1.5/staticcheck/testdata/src/CheckSelfAssignment/CheckSelfAssignment.go

   1 package pkg
   2
   3 func fn(x int) {
   4         var z int
   5         var y int
   6         x = x             // want `self-assignment`
   7         y = y             // want `self-assignment`
   8         y, x, z = y, x, 1 // want `self-assignment of y to y` `self-assignment of x to x`
   9         y = x
  10         _ = y
  11         _ = x
  12         _ = z
  13         func() {
  14                 x := x
  15                 println(x)
  16         }()
  17 }
  18
  19 func fn1() {
  20         var (
  21                 x  []byte
  22                 ch chan int
  23         )
  24         x[42] = x[42]                         // want `self-assignment`
  25         x[pure(42)] = x[pure(42)]             // want `self-assignment`
  26         x[pure(pure(42))] = x[pure(pure(42))] // want `self-assignment`
  27         x[impure(42)] = x[impure(42)]
  28         x[impure(pure(42))] = x[impure(pure(42))]
  29         x[pure(impure(42))] = x[pure(impure(42))]
  30         x[pure(<-ch)] = x[pure(<-ch)]
  31         x[pure(pure(<-ch))] = x[pure(pure(<-ch))]
  32         x[<-ch] = x[<-ch]
  33
  34         type T struct {
  35                 x []int
  36         }
  37         var ts []T
  38         ts[impure(42)].x = ts[impure(42)].x
  39         m := map[*int]int{}
  40         m[ptr1()] = m[ptr1()]
  41         m[ptr2()] = m[ptr2()]
  42         m[new(int)] = m[new(int)]
  43
  44         m2 := map[int]int{}
  45         m2[len(x)] = m2[len(x)] // want `self-assignment`
  46
  47         gen1()[0] = gen1()[0]
  48         gen2(0)[0] = gen2(0)[0] // want `self-assignment`
  49         gen3(0)[0] = gen3(0)[0]
  50 }
  51
  52 func ptr1() *int {
  53         return new(int)
  54 }
  55
  56 func ptr2() *int {
  57         x := 0
  58         return &x
  59 }
  60
  61 func gen1() []int {
  62         return nil
  63 }
  64
  65 func gen2(x int) []int {
  66         return nil
  67 }
  68
  69 func gen3(x int) []int {
  70         return make([]int, 0)
  71 }
  72
  73 func pure(n int) int {
  74         return n
  75 }
  76
  77 func impure(n int) int {
  78         println(n)
  79         return n
  80 }