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// Copyright 2013 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 astutil_test
// This file defines tests of PathEnclosingInterval.
// TODO(adonovan): exhaustive tests that run over the whole input
// tree, not just handcrafted examples.
import (
"bytes"
"fmt"
"go/ast"
"go/parser"
"go/token"
"strings"
"testing"
"golang.org/x/tools/go/ast/astutil"
)
// pathToString returns a string containing the concrete types of the
// nodes in path.
func pathToString(path []ast.Node) string {
var buf bytes.Buffer
fmt.Fprint(&buf, "[")
for i, n := range path {
if i > 0 {
fmt.Fprint(&buf, " ")
}
fmt.Fprint(&buf, strings.TrimPrefix(fmt.Sprintf("%T", n), "*ast."))
}
fmt.Fprint(&buf, "]")
return buf.String()
}
// findInterval parses input and returns the [start, end) positions of
// the first occurrence of substr in input. f==nil indicates failure;
// an error has already been reported in that case.
//
func findInterval(t *testing.T, fset *token.FileSet, input, substr string) (f *ast.File, start, end token.Pos) {
f, err := parser.ParseFile(fset, "<input>", input, 0)
if err != nil {
t.Errorf("parse error: %s", err)
return
}
i := strings.Index(input, substr)
if i < 0 {
t.Errorf("%q is not a substring of input", substr)
f = nil
return
}
filePos := fset.File(f.Package)
return f, filePos.Pos(i), filePos.Pos(i + len(substr))
}
// Common input for following tests.
const input = `
// Hello.
package main
import "fmt"
func f() {}
func main() {
z := (x + y) // add them
f() // NB: ExprStmt and its CallExpr have same Pos/End
}
`
func TestPathEnclosingInterval_Exact(t *testing.T) {
// For the exact tests, we check that a substring is mapped to
// the canonical string for the node it denotes.
tests := []struct {
substr string // first occurrence of this string indicates interval
node string // complete text of expected containing node
}{
{"package",
input[11 : len(input)-1]},
{"\npack",
input[11 : len(input)-1]},
{"main",
"main"},
{"import",
"import \"fmt\""},
{"\"fmt\"",
"\"fmt\""},
{"\nfunc f() {}\n",
"func f() {}"},
{"x ",
"x"},
{" y",
"y"},
{"z",
"z"},
{" + ",
"x + y"},
{" :=",
"z := (x + y)"},
{"x + y",
"x + y"},
{"(x + y)",
"(x + y)"},
{" (x + y) ",
"(x + y)"},
{" (x + y) // add",
"(x + y)"},
{"func",
"func f() {}"},
{"func f() {}",
"func f() {}"},
{"\nfun",
"func f() {}"},
{" f",
"f"},
}
for _, test := range tests {
f, start, end := findInterval(t, new(token.FileSet), input, test.substr)
if f == nil {
continue
}
path, exact := astutil.PathEnclosingInterval(f, start, end)
if !exact {
t.Errorf("PathEnclosingInterval(%q) not exact", test.substr)
continue
}
if len(path) == 0 {
if test.node != "" {
t.Errorf("PathEnclosingInterval(%q).path: got [], want %q",
test.substr, test.node)
}
continue
}
if got := input[path[0].Pos():path[0].End()]; got != test.node {
t.Errorf("PathEnclosingInterval(%q): got %q, want %q (path was %s)",
test.substr, got, test.node, pathToString(path))
continue
}
}
}
func TestPathEnclosingInterval_Paths(t *testing.T) {
// For these tests, we check only the path of the enclosing
// node, but not its complete text because it's often quite
// large when !exact.
tests := []struct {
substr string // first occurrence of this string indicates interval
path string // the pathToString(),exact of the expected path
}{
{"// add",
"[BlockStmt FuncDecl File],false"},
{"(x + y",
"[ParenExpr AssignStmt BlockStmt FuncDecl File],false"},
{"x +",
"[BinaryExpr ParenExpr AssignStmt BlockStmt FuncDecl File],false"},
{"z := (x",
"[AssignStmt BlockStmt FuncDecl File],false"},
{"func f",
"[FuncDecl File],false"},
{"func f()",
"[FuncDecl File],false"},
{" f()",
"[FuncDecl File],false"},
{"() {}",
"[FuncDecl File],false"},
{"// Hello",
"[File],false"},
{" f",
"[Ident FuncDecl File],true"},
{"func ",
"[FuncDecl File],true"},
{"mai",
"[Ident File],true"},
{"f() // NB",
"[CallExpr ExprStmt BlockStmt FuncDecl File],true"},
}
for _, test := range tests {
f, start, end := findInterval(t, new(token.FileSet), input, test.substr)
if f == nil {
continue
}
path, exact := astutil.PathEnclosingInterval(f, start, end)
if got := fmt.Sprintf("%s,%v", pathToString(path), exact); got != test.path {
t.Errorf("PathEnclosingInterval(%q): got %q, want %q",
test.substr, got, test.path)
continue
}
}
}