1 files changed, 365 insertions, 0 deletions
diff --git a/libgo/go/cmd/go/internal/modfile/read_test.go b/libgo/go/cmd/go/internal/modfile/read_test.go
new file mode 100644
index 00000000000..8cb1a3908c5
--- /dev/null
+++ b/libgo/go/cmd/go/internal/modfile/read_test.go
@@ -0,0 +1,365 @@
+// 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 modfile
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"reflect"
+	"strings"
+	"testing"
+)
+
+// exists reports whether the named file exists.
+func exists(name string) bool {
+	_, err := os.Stat(name)
+	return err == nil
+}
+
+// Test that reading and then writing the golden files
+// does not change their output.
+func TestPrintGolden(t *testing.T) {
+	outs, err := filepath.Glob("testdata/*.golden")
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, out := range outs {
+		testPrint(t, out, out)
+	}
+}
+
+// testPrint is a helper for testing the printer.
+// It reads the file named in, reformats it, and compares
+// the result to the file named out.
+func testPrint(t *testing.T, in, out string) {
+	data, err := ioutil.ReadFile(in)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+
+	golden, err := ioutil.ReadFile(out)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+
+	base := "testdata/" + filepath.Base(in)
+	f, err := parse(in, data)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+
+	ndata := Format(f)
+
+	if !bytes.Equal(ndata, golden) {
+		t.Errorf("formatted %s incorrectly: diff shows -golden, +ours", base)
+		tdiff(t, string(golden), string(ndata))
+		return
+	}
+}
+
+func TestParseLax(t *testing.T) {
+	badFile := []byte(`module m
+		surprise attack
+		x y (
+			z
+		)
+		exclude v1.2.3
+		replace <-!!!
+	`)
+	_, err := ParseLax("file", badFile, nil)
+	if err != nil {
+		t.Fatalf("ParseLax did not ignore irrelevant errors: %v", err)
+	}
+}
+
+// Test that when files in the testdata directory are parsed
+// and printed and parsed again, we get the same parse tree
+// both times.
+func TestPrintParse(t *testing.T) {
+	outs, err := filepath.Glob("testdata/*")
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, out := range outs {
+		data, err := ioutil.ReadFile(out)
+		if err != nil {
+			t.Error(err)
+			continue
+		}
+
+		base := "testdata/" + filepath.Base(out)
+		f, err := parse(base, data)
+		if err != nil {
+			t.Errorf("parsing original: %v", err)
+			continue
+		}
+
+		ndata := Format(f)
+		f2, err := parse(base, ndata)
+		if err != nil {
+			t.Errorf("parsing reformatted: %v", err)
+			continue
+		}
+
+		eq := eqchecker{file: base}
+		if err := eq.check(f, f2); err != nil {
+			t.Errorf("not equal (parse/Format/parse): %v", err)
+		}
+
+		pf1, err := Parse(base, data, nil)
+		if err != nil {
+			switch base {
+			case "testdata/replace2.in", "testdata/gopkg.in.golden":
+				t.Errorf("should parse %v: %v", base, err)
+			}
+		}
+		if err == nil {
+			pf2, err := Parse(base, ndata, nil)
+			if err != nil {
+				t.Errorf("Parsing reformatted: %v", err)
+				continue
+			}
+			eq := eqchecker{file: base}
+			if err := eq.check(pf1, pf2); err != nil {
+				t.Errorf("not equal (parse/Format/Parse): %v", err)
+			}
+
+			ndata2, err := pf1.Format()
+			if err != nil {
+				t.Errorf("reformat: %v", err)
+			}
+			pf3, err := Parse(base, ndata2, nil)
+			if err != nil {
+				t.Errorf("Parsing reformatted2: %v", err)
+				continue
+			}
+			eq = eqchecker{file: base}
+			if err := eq.check(pf1, pf3); err != nil {
+				t.Errorf("not equal (Parse/Format/Parse): %v", err)
+			}
+			ndata = ndata2
+		}
+
+		if strings.HasSuffix(out, ".in") {
+			golden, err := ioutil.ReadFile(strings.TrimSuffix(out, ".in") + ".golden")
+			if err != nil {
+				t.Error(err)
+				continue
+			}
+			if !bytes.Equal(ndata, golden) {
+				t.Errorf("formatted %s incorrectly: diff shows -golden, +ours", base)
+				tdiff(t, string(golden), string(ndata))
+				return
+			}
+		}
+	}
+}
+
+// An eqchecker holds state for checking the equality of two parse trees.
+type eqchecker struct {
+	file string
+	pos  Position
+}
+
+// errorf returns an error described by the printf-style format and arguments,
+// inserting the current file position before the error text.
+func (eq *eqchecker) errorf(format string, args ...interface{}) error {
+	return fmt.Errorf("%s:%d: %s", eq.file, eq.pos.Line,
+		fmt.Sprintf(format, args...))
+}
+
+// check checks that v and w represent the same parse tree.
+// If not, it returns an error describing the first difference.
+func (eq *eqchecker) check(v, w interface{}) error {
+	return eq.checkValue(reflect.ValueOf(v), reflect.ValueOf(w))
+}
+
+var (
+	posType      = reflect.TypeOf(Position{})
+	commentsType = reflect.TypeOf(Comments{})
+)
+
+// checkValue checks that v and w represent the same parse tree.
+// If not, it returns an error describing the first difference.
+func (eq *eqchecker) checkValue(v, w reflect.Value) error {
+	// inner returns the innermost expression for v.
+	// if v is a non-nil interface value, it returns the concrete
+	// value in the interface.
+	inner := func(v reflect.Value) reflect.Value {
+		for {
+			if v.Kind() == reflect.Interface && !v.IsNil() {
+				v = v.Elem()
+				continue
+			}
+			break
+		}
+		return v
+	}
+
+	v = inner(v)
+	w = inner(w)
+	if v.Kind() == reflect.Invalid && w.Kind() == reflect.Invalid {
+		return nil
+	}
+	if v.Kind() == reflect.Invalid {
+		return eq.errorf("nil interface became %s", w.Type())
+	}
+	if w.Kind() == reflect.Invalid {
+		return eq.errorf("%s became nil interface", v.Type())
+	}
+
+	if v.Type() != w.Type() {
+		return eq.errorf("%s became %s", v.Type(), w.Type())
+	}
+
+	if p, ok := v.Interface().(Expr); ok {
+		eq.pos, _ = p.Span()
+	}
+
+	switch v.Kind() {
+	default:
+		return eq.errorf("unexpected type %s", v.Type())
+
+	case reflect.Bool, reflect.Int, reflect.String:
+		vi := v.Interface()
+		wi := w.Interface()
+		if vi != wi {
+			return eq.errorf("%v became %v", vi, wi)
+		}
+
+	case reflect.Slice:
+		vl := v.Len()
+		wl := w.Len()
+		for i := 0; i < vl || i < wl; i++ {
+			if i >= vl {
+				return eq.errorf("unexpected %s", w.Index(i).Type())
+			}
+			if i >= wl {
+				return eq.errorf("missing %s", v.Index(i).Type())
+			}
+			if err := eq.checkValue(v.Index(i), w.Index(i)); err != nil {
+				return err
+			}
+		}
+
+	case reflect.Struct:
+		// Fields in struct must match.
+		t := v.Type()
+		n := t.NumField()
+		for i := 0; i < n; i++ {
+			tf := t.Field(i)
+			switch {
+			default:
+				if err := eq.checkValue(v.Field(i), w.Field(i)); err != nil {
+					return err
+				}
+
+			case tf.Type == posType: // ignore positions
+			case tf.Type == commentsType: // ignore comment assignment
+			}
+		}
+
+	case reflect.Ptr, reflect.Interface:
+		if v.IsNil() != w.IsNil() {
+			if v.IsNil() {
+				return eq.errorf("unexpected %s", w.Elem().Type())
+			}
+			return eq.errorf("missing %s", v.Elem().Type())
+		}
+		if err := eq.checkValue(v.Elem(), w.Elem()); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// diff returns the output of running diff on b1 and b2.
+func diff(b1, b2 []byte) (data []byte, err error) {
+	f1, err := ioutil.TempFile("", "testdiff")
+	if err != nil {
+		return nil, err
+	}
+	defer os.Remove(f1.Name())
+	defer f1.Close()
+
+	f2, err := ioutil.TempFile("", "testdiff")
+	if err != nil {
+		return nil, err
+	}
+	defer os.Remove(f2.Name())
+	defer f2.Close()
+
+	f1.Write(b1)
+	f2.Write(b2)
+
+	data, err = exec.Command("diff", "-u", f1.Name(), f2.Name()).CombinedOutput()
+	if len(data) > 0 {
+		// diff exits with a non-zero status when the files don't match.
+		// Ignore that failure as long as we get output.
+		err = nil
+	}
+	return
+}
+
+// tdiff logs the diff output to t.Error.
+func tdiff(t *testing.T, a, b string) {
+	data, err := diff([]byte(a), []byte(b))
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	t.Error(string(data))
+}
+
+var modulePathTests = []struct {
+	input    []byte
+	expected string
+}{
+	{input: []byte("module \"github.com/rsc/vgotest\""), expected: "github.com/rsc/vgotest"},
+	{input: []byte("module github.com/rsc/vgotest"), expected: "github.com/rsc/vgotest"},
+	{input: []byte("module  \"github.com/rsc/vgotest\""), expected: "github.com/rsc/vgotest"},
+	{input: []byte("module  github.com/rsc/vgotest"), expected: "github.com/rsc/vgotest"},
+	{input: []byte("module `github.com/rsc/vgotest`"), expected: "github.com/rsc/vgotest"},
+	{input: []byte("module \"github.com/rsc/vgotest/v2\""), expected: "github.com/rsc/vgotest/v2"},
+	{input: []byte("module github.com/rsc/vgotest/v2"), expected: "github.com/rsc/vgotest/v2"},
+	{input: []byte("module \"gopkg.in/yaml.v2\""), expected: "gopkg.in/yaml.v2"},
+	{input: []byte("module gopkg.in/yaml.v2"), expected: "gopkg.in/yaml.v2"},
+	{input: []byte("module \"gopkg.in/check.v1\"\n"), expected: "gopkg.in/check.v1"},
+	{input: []byte("module \"gopkg.in/check.v1\n\""), expected: ""},
+	{input: []byte("module gopkg.in/check.v1\n"), expected: "gopkg.in/check.v1"},
+	{input: []byte("module \"gopkg.in/check.v1\"\r\n"), expected: "gopkg.in/check.v1"},
+	{input: []byte("module gopkg.in/check.v1\r\n"), expected: "gopkg.in/check.v1"},
+	{input: []byte("module \"gopkg.in/check.v1\"\n\n"), expected: "gopkg.in/check.v1"},
+	{input: []byte("module gopkg.in/check.v1\n\n"), expected: "gopkg.in/check.v1"},
+	{input: []byte("module \n\"gopkg.in/check.v1\"\n\n"), expected: ""},
+	{input: []byte("module \ngopkg.in/check.v1\n\n"), expected: ""},
+	{input: []byte("module \"gopkg.in/check.v1\"asd"), expected: ""},
+	{input: []byte("module \n\"gopkg.in/check.v1\"\n\n"), expected: ""},
+	{input: []byte("module \ngopkg.in/check.v1\n\n"), expected: ""},
+	{input: []byte("module \"gopkg.in/check.v1\"asd"), expected: ""},
+	{input: []byte("module  \nmodule a/b/c "), expected: "a/b/c"},
+	{input: []byte("module \"   \""), expected: "   "},
+	{input: []byte("module   "), expected: ""},
+	{input: []byte("module \"  a/b/c  \""), expected: "  a/b/c  "},
+	{input: []byte("module \"github.com/rsc/vgotest1\" // with a comment"), expected: "github.com/rsc/vgotest1"},
+}
+
+func TestModulePath(t *testing.T) {
+	for _, test := range modulePathTests {
+		t.Run(string(test.input), func(t *testing.T) {
+			result := ModulePath(test.input)
+			if result != test.expected {
+				t.Fatalf("ModulePath(%q): %s, want %s", string(test.input), result, test.expected)
+			}
+		})
+	}
+}