Support Go 1.18 methods with type parameters

go.mod

@@ -2,4 +2,7 @@ module github.com/axw/gocov
 
 go 1.12
 
-require golang.org/x/tools v0.0.0-20190617190820-da514acc4774
+require (
+ github.com/stretchr/testify v1.7.1
+ golang.org/x/tools v0.0.0-20190617190820-da514acc4774
+)

go.sum

@@ -1,7 +1,18 @@
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.1 h1:5TQK59W5E3v0r2duFAb7P95B6hEeOyEnHRa8MjYSMTY=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20190617190820-da514acc4774 h1:CQVOmarCBFzTx0kbOU0ru54Cvot8SdSrNYjZPhQl+gk=
 golang.org/x/tools v0.0.0-20190617190820-da514acc4774/go.mod h1:/rFqwRUd4F7ZHNgwSSTFct+R/Kf4OFW1sUzUTQQTgfc=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

gocov/convert.go

@@ -189,6 +189,30 @@ type FuncVisitor struct {
  funcs []*FuncExtent
 }
 
+func functionName(f *ast.FuncDecl) string {
+ name := f.Name.Name
+ if f.Recv == nil {
+ return name
+ } else {
+ // Function name is prepended with "T." if there is a receiver, where
+ // T is the type of the receiver, dereferenced if it is a pointer.
+ return exprName(f.Recv.List[0].Type) + "." + name
+ }
+}
+
+func exprName(x ast.Expr) string {
+ switch y := x.(type) {
+ case *ast.StarExpr:
+ return exprName(y.X)
+ case *ast.IndexExpr:
+ return fmt.Sprintf("%s[%s]", exprName(y.X), exprName(y.Index))
+ case *ast.Ident:
+ return y.Name
+ default:
+ return ""
+ }
+}
+
 // Visit implements the ast.Visitor interface.
 func (v *FuncVisitor) Visit(node ast.Node) ast.Visitor {
  var body *ast.BlockStmt
@@ -198,18 +222,7 @@ func (v *FuncVisitor) Visit(node ast.Node) ast.Visitor {
  body = n.Body
  case *ast.FuncDecl:
  body = n.Body
- name = n.Name.Name
- // Function name is prepended with "T." if there is a receiver, where
- // T is the type of the receiver, dereferenced if it is a pointer.
- if n.Recv != nil {
- field := n.Recv.List[0]
- switch recv := field.Type.(type) {
- case *ast.StarExpr:
- name = recv.X.(*ast.Ident).Name + "." + name
- case *ast.Ident:
- name = recv.Name + "." + name
- }
- }
+ name = functionName(n)
  }
  if body != nil {
  start := v.fset.Position(node.Pos())

gocov/convert_test.go

@@ -0,0 +1,40 @@
+package main
+
+import (
+ "go/ast"
+ "go/parser"
+ "go/token"
+ "testing"
+
+ "github.com/stretchr/testify/assert"
+)
+
+func TestExprName(t *testing.T) {
+ source := `
+package foo
+
+func Function() {}
+func (x Foo) Method() {}
+func (x *Foo) PtrMethod() {}
+func (x *Foo[T]) GenericMethod() {}
+`
+
+ fset := token.NewFileSet()
+ parsed, err := parser.ParseFile(fset, "", source, 0)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ function0 := parsed.Decls[0].(*ast.FuncDecl)
+ assert.Equal(t, "Function", functionName(function0))
+
+ function1 := parsed.Decls[1].(*ast.FuncDecl)
+ assert.Equal(t, "Foo.Method", functionName(function1))
+
+ function2 := parsed.Decls[2].(*ast.FuncDecl)
+ assert.Equal(t, "Foo.PtrMethod", functionName(function2))
+
+ function3 := parsed.Decls[3].(*ast.FuncDecl)
+ assert.Equal(t, "Foo[T].GenericMethod", functionName(function3))
+
+}