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// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package typeutil_test
import (
"go/ast"
"go/importer"
"go/parser"
"go/token"
"go/types"
"strings"
"testing"
"golang.org/x/tools/go/types/typeutil"
)
func TestStaticCallee(t *testing.T) {
const src = `package p
import "fmt"
type T int
func g(int)
var f = g
var x int
type s struct{ f func(int) }
func (s) g(int)
type I interface{ f(int) }
var a struct{b struct{c s}}
func calls() {
g(x) // a declared func
s{}.g(x) // a concrete method
a.b.c.g(x) // same
fmt.Println(x) // declared func, qualified identifier
}
func noncalls() {
_ = T(x) // a type
f(x) // a var
panic(x) // a built-in
s{}.f(x) // a field
I(nil).f(x) // interface method
}
`
// parse
fset := token.NewFileSet()
f, err := parser.ParseFile(fset, "p.go", src, 0)
if err != nil {
t.Fatal(err)
}
// type-check
info := &types.Info{
Uses: make(map[*ast.Ident]types.Object),
Selections: make(map[*ast.SelectorExpr]*types.Selection),
}
cfg := &types.Config{Importer: importer.For("source", nil)}
if _, err := cfg.Check("p", fset, []*ast.File{f}, info); err != nil {
t.Fatal(err)
}
for _, decl := range f.Decls {
if decl, ok := decl.(*ast.FuncDecl); ok && strings.HasSuffix(decl.Name.Name, "calls") {
wantCallee := decl.Name.Name == "calls" // false within func noncalls()
ast.Inspect(decl.Body, func(n ast.Node) bool {
if call, ok := n.(*ast.CallExpr); ok {
fn := typeutil.StaticCallee(info, call)
if fn == nil && wantCallee {
t.Errorf("%s: StaticCallee returned nil",
fset.Position(call.Lparen))
} else if fn != nil && !wantCallee {
t.Errorf("%s: StaticCallee returned %s, want nil",
fset.Position(call.Lparen), fn)
}
}
return true
})
}
}
}
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