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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 g[A any, P interface{ctype1| ~ctype2}](a1 A, p1 P) {}
type PT[T constraint] struct{ t T }
var v GT[targ1]
var h = g[ targ2, targ3]
`
func TestPathEnclosingInterval_Exact(t *testing.T) {
type testCase struct {
substr string // first occurrence of this string indicates interval
node string // complete text of expected containing node
}
dup := func(s string) testCase { return testCase{s, s} }
// For the exact tests, we check that a substring is mapped to
// the canonical string for the node it denotes.
tests := []testCase{
{"package",
input[11 : len(input)-1]},
{"\npack",
input[11 : len(input)-1]},
dup("main"),
{"import",
"import \"fmt\""},
dup("\"fmt\""),
{"\nfunc f() {}\n",
"func f() {}"},
{"x ",
"x"},
{" y",
"y"},
dup("z"),
{" + ",
"x + y"},
{" :=",
"z := (x + y)"},
dup("x + y"),
dup("(x + y)"),
{" (x + y) ",
"(x + y)"},
{" (x + y) // add",
"(x + y)"},
{"func",
"func f() {}"},
dup("func f() {}"),
{"\nfun",
"func f() {}"},
{" f",
"f"},
dup("[A any, P interface{ctype1| ~ctype2}]"),
{"[", "[A any, P interface{ctype1| ~ctype2}]"},
dup("A"),
{" any", "any"},
dup("ctype1"),
{"|", "ctype1| ~ctype2"},
dup("ctype2"),
{"~", "~ctype2"},
dup("~ctype2"),
{" ~ctype2", "~ctype2"},
{"]", "[A any, P interface{ctype1| ~ctype2}]"},
dup("a1"),
dup("a1 A"),
dup("(a1 A, p1 P)"),
dup("type PT[T constraint] struct{ t T }"),
dup("PT"),
dup("[T constraint]"),
dup("constraint"),
dup("targ1"),
{" targ2", "targ2"},
dup("g[ targ2, targ3]"),
}
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) {
type testCase struct {
substr string // first occurrence of this string indicates interval
path string // the pathToString(),exact of the expected path
}
// 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 := []testCase{
{"// 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"},
{" any", "[Ident Field FieldList FuncDecl File],true"},
{"|", "[BinaryExpr Field FieldList InterfaceType Field FieldList FuncDecl File],true"},
{"ctype2",
"[Ident UnaryExpr BinaryExpr Field FieldList InterfaceType Field FieldList FuncDecl File],true"},
{"a1", "[Ident Field FieldList FuncDecl File],true"},
{"PT[T constraint]", "[TypeSpec GenDecl File],false"},
{"[T constraint]", "[FieldList TypeSpec GenDecl File],true"},
{"targ2", "[Ident IndexListExpr ValueSpec GenDecl 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
}
}
}