issue48471.go

     1  // errorcheck
     2  
     3  // Copyright 2021 The Go Authors. All rights reserved.
     4  // Use of this source code is governed by a BSD-style
     5  // license that can be found in the LICENSE file.
     6  
     7  package p
     8  
     9  type I interface{ M(int) }
    10  
    11  type T struct{}
    12  
    13  type T2 struct{}
    14  
    15  func (*T2) m(int)
    16  
    17  type T3 struct{}
    18  
    19  func (*T3) M(string) {}
    20  
    21  type T4 struct{}
    22  
    23  func (*T4) M(int)
    24  
    25  type T5 struct{}
    26  
    27  func (T5) m(int) {}
    28  
    29  type T6 struct{}
    30  
    31  func (T6) m(int) string { return "" }
    32  
    33  func f(I)
    34  
    35  func g() {
    36  	f(new(T)) // ERROR "cannot use new\(T\) \(.*type \*T\) as I value in argument to f: \*T does not implement I \(missing method M\)"
    37  
    38  	var i I
    39  	i = new(T)    // ERROR "cannot use new\(T\) \(.*type \*T\) as I value in assignment: \*T does not implement I \(missing method M\)"
    40  	i = I(new(T)) // ERROR "cannot convert new\(T\) \(.*type \*T\) to type I: \*T does not implement I \(missing method M\)"
    41  	i = new(T2)   // ERROR "cannot use new\(T2\) \(.*type \*T2\) as I value in assignment: \*T2 does not implement I \(missing method M\)\n\t\thave m\(int\)\n\t\twant M\(int\)"
    42  
    43  	i = new(T3) // ERROR "cannot use new\(T3\) \(.*type \*T3\) as I value in assignment: \*T3 does not implement I \(wrong type for method M\)\n\t\thave M\(string\)\n\t\twant M\(int\)"
    44  
    45  	i = T4{}   // ERROR "cannot use T4\{\} \(.*type T4\) as I value in assignment: T4 does not implement I \(method M has pointer receiver\)"
    46  	i = new(I) // ERROR "cannot use new\(I\) \(.*type \*I\) as I value in assignment: \*I does not implement I \(type \*I is pointer to interface, not interface\)"
    47  
    48  	_ = i.(*T2) // ERROR "impossible type assertion: i.\(\*T2\)\n\t\*T2 does not implement I \(missing method M\)\n\t\thave m\(int\)\n\t\twant M\(int\)"
    49  	_ = i.(*T3) // ERROR "impossible type assertion: i.\(\*T3\)\n\t\*T3 does not implement I \(wrong type for method M\)\n\t\thave M\(string\)\n\t\twant M\(int\)"
    50  	_ = i.(T5)  // ERROR ""impossible type assertion: i.\(T5\)\n\tT5 does not implement I \(missing method M\)\n\t\thave m\(int\)\n\t\twant M\(int\)"
    51  	_ = i.(T6)  // ERROR "impossible type assertion: i.\(T6\)\n\tT6 does not implement I \(missing method M\)\n\t\thave m\(int\) string\n\t\twant M\(int\)"
    52  
    53  	var t *T4
    54  	t = i // ERROR "cannot use i \(variable of type I\) as \*T4 value in assignment: need type assertion"
    55  	_ = t
    56  }
    57
View as plain text