cmd/testscript: initial commit (#41)

cmd/testscript/help.go

@@ -0,0 +1,117 @@
+package main
+
+import (
+	"fmt"
+	"io"
+)
+
+func mainUsage(f io.Writer) {
+	fmt.Fprint(f, mainHelp)
+}
+
+var mainHelp = `
+The testscript command runs github.com/rogpeppe/go-internal/testscript scripts
+in a fresh temporary work directory tree.
+
+Usage:
+    testscript [-v] files...
+
+The testscript command is designed to make it easy to create self-contained
+reproductions of command sequences.
+
+Each file is opened as a script and run as described in the documentation for
+github.com/rogpeppe/go-internal/testscript. The special filename "-" is
+interpreted as the standard input.
+
+As a special case, supporting files/directories in the .gomodproxy subdirectory
+will be served via a github.com/rogpeppe/go-internal/goproxytest server which
+is available to each script via the GOPROXY environment variable. The contents
+of the .gomodproxy subdirectory are not available to the script except via the
+proxy server. See the documentation for
+github.com/rogpeppe/go-internal/goproxytest for details on the format of these
+files/directories.
+
+Examples
+========
+
+The following example, fruit.txt, shows a simple reproduction that includes
+.gomodproxy supporting files:
+
+    go get -m fruit.com
+    go list fruit.com/...
+    stdout 'fruit.com/fruit'
+
+    -- go.mod --
+    module mod
+
+    -- .gomodproxy/fruit.com_v1.0.0/.mod --
+    module fruit.com
+
+    -- .gomodproxy/fruit.com_v1.0.0/.info --
+    {"Version":"v1.0.0","Time":"2018-10-22T18:45:39Z"}
+
+    -- .gomodproxy/fruit.com_v1.0.0/fruit/fruit.go --
+    package fruit
+
+    const Name = "Apple"
+
+Running testscript -v fruit.txt we get:
+
+    ...
+    > go get -m fruit.com
+    [stderr]
+    go: finding fruit.com v1.0.0
+
+    > go list fruit.com/...
+    [stdout]
+    fruit.com/fruit
+
+    [stderr]
+    go: downloading fruit.com v1.0.0
+
+    > stdout 'fruit.com/fruit'
+    PASS
+
+
+The following example, goimports.txt, shows a simple reproduction involving
+goimports:
+
+    go install golang.org/x/tools/cmd/goimports
+
+    # check goimports help information
+    exec goimports -d main.go
+    stdout 'import "math"'
+
+    -- go.mod --
+    module mod
+
+    require golang.org/x/tools v0.0.0-20181221235234-d00ac6d27372
+
+    -- main.go --
+    package mod
+
+    const Pi = math.Pi
+
+Running testscript -v goimports.txt we get:
+
+    ...
+    > go install golang.org/x/tools/cmd/goimports
+    [stderr]
+    go: finding golang.org/x/tools v0.0.0-20181221235234-d00ac6d27372
+    go: downloading golang.org/x/tools v0.0.0-20181221235234-d00ac6d27372
+
+    # check goimports help information (0.015s)
+    > exec goimports -d main.go
+    [stdout]
+    diff -u main.go.orig main.go
+    --- main.go.orig        2019-01-08 16:03:35.861907738 +0000
+    +++ main.go     2019-01-08 16:03:35.861907738 +0000
+    @@ -1,3 +1,5 @@
+     package mod
+
+    +import "math"
+    +
+     const Pi = math.Pi
+    > stdout 'import "math"'
+    PASS
+`[1:]

cmd/testscript/main.go

@@ -0,0 +1,222 @@
+// 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 main
+
+import (
+	"errors"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	"github.com/rogpeppe/go-internal/goproxytest"
+	"github.com/rogpeppe/go-internal/gotooltest"
+	"github.com/rogpeppe/go-internal/testscript"
+	"github.com/rogpeppe/go-internal/txtar"
+)
+
+const (
+	// goModProxyDir is the special subdirectory in a txtar script's supporting files
+	// within which we expect to find github.com/rogpeppe/go-internal/goproxytest
+	// directories.
+	goModProxyDir = ".gomodproxy"
+)
+
+func main() {
+	os.Exit(main1())
+}
+
+func main1() int {
+	if err := mainerr(); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		return 1
+	}
+	return 0
+}
+
+func mainerr() (retErr error) {
+	fs := flag.NewFlagSet(os.Args[0], flag.ContinueOnError)
+	fs.Usage = func() {
+		mainUsage(os.Stderr)
+	}
+	fWork := fs.Bool("work", false, "print temporary work directory and do not remove when done")
+	fVerbose := fs.Bool("v", false, "run tests verbosely")
+	if err := fs.Parse(os.Args[1:]); err != nil {
+		return err
+	}
+
+	td, err := ioutil.TempDir("", "testscript")
+	if err != nil {
+		return fmt.Errorf("unable to create temp dir: %v", err)
+	}
+	fmt.Printf("temporary work directory: %v\n", td)
+	if !*fWork {
+		defer os.RemoveAll(td)
+	}
+
+	files := fs.Args()
+	if len(files) == 0 {
+		files = []string{"-"}
+	}
+
+	for i, fileName := range files {
+		// TODO make running files concurrent by default? If we do, note we'll need to do
+		// something smarter with the runner stdout and stderr below
+		runDir := filepath.Join(td, strconv.Itoa(i))
+		if err := os.Mkdir(runDir, 0777); err != nil {
+			return fmt.Errorf("failed to create a run directory within %v for %v: %v", td, fileName, err)
+		}
+		if err := run(runDir, fileName, *fVerbose); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+var (
+	failedRun = errors.New("failed run")
+	skipRun   = errors.New("skip")
+)
+
+type runner struct {
+	verbose bool
+}
+
+func (r runner) Skip(is ...interface{}) {
+	panic(skipRun)
+}
+
+func (r runner) Fatal(is ...interface{}) {
+	r.Log(is...)
+	r.FailNow()
+}
+
+func (r runner) Parallel() {
+	// No-op for now; we are currently only running a single script in a
+	// testscript instance.
+}
+
+func (r runner) Log(is ...interface{}) {
+	fmt.Print(is...)
+}
+
+func (r runner) FailNow() {
+	panic(failedRun)
+}
+
+func (r runner) Run(n string, f func(t testscript.T)) {
+	// For now we we don't top/tail the run of a subtest. We are currently only
+	// running a single script in a testscript instance, which means that we
+	// will only have a single subtest.
+	f(r)
+}
+
+func (r runner) Verbose() bool {
+	return r.verbose
+}
+
+func run(runDir, fileName string, verbose bool) error {
+	var ar *txtar.Archive
+	var err error
+
+	mods := filepath.Join(runDir, goModProxyDir)
+
+	if err := os.MkdirAll(mods, 0777); err != nil {
+		return fmt.Errorf("failed to create goModProxy dir: %v", err)
+	}
+
+	if fileName == "-" {
+		fileName = "<stdin>"
+		byts, err := ioutil.ReadAll(os.Stdin)
+		if err != nil {
+			return fmt.Errorf("failed to read from stdin: %v", err)
+		}
+		ar = txtar.Parse(byts)
+	} else {
+		ar, err = txtar.ParseFile(fileName)
+	}
+
+	if err != nil {
+		return fmt.Errorf("failed to txtar parse %v: %v", fileName, err)
+	}
+
+	var script, gomodProxy txtar.Archive
+	script.Comment = ar.Comment
+
+	for _, f := range ar.Files {
+		fp := filepath.Clean(filepath.FromSlash(f.Name))
+		parts := strings.Split(fp, string(os.PathSeparator))
+
+		if len(parts) > 1 && parts[0] == goModProxyDir {
+			gomodProxy.Files = append(gomodProxy.Files, f)
+		} else {
+			script.Files = append(script.Files, f)
+		}
+	}
+
+	if txtar.Write(&gomodProxy, runDir); err != nil {
+		return fmt.Errorf("failed to write .gomodproxy files: %v", err)
+	}
+
+	if err := ioutil.WriteFile(filepath.Join(runDir, "script.txt"), txtar.Format(&script), 0666); err != nil {
+		return fmt.Errorf("failed to write script for %v: %v", fileName, err)
+	}
+
+	p := testscript.Params{
+		Dir: runDir,
+	}
+
+	if len(gomodProxy.Files) > 0 {
+		srv, err := goproxytest.NewServer(mods, "")
+		if err != nil {
+			return fmt.Errorf("cannot start proxy for %v: %v", fileName, err)
+		}
+		defer srv.Close()
+
+		currSetup := p.Setup
+
+		p.Setup = func(env *testscript.Env) error {
+			env.Vars = append(env.Vars, "GOPROXY="+srv.URL)
+			if currSetup != nil {
+				return currSetup(env)
+			}
+			return nil
+		}
+	}
+
+	if _, err := exec.LookPath("go"); err == nil {
+		if err := gotooltest.Setup(&p); err != nil {
+			return fmt.Errorf("failed to setup go tool for %v run: %v", fileName, err)
+		}
+	}
+
+	r := runner{
+		verbose: verbose,
+	}
+
+	func() {
+		defer func() {
+			switch recover() {
+			case nil, skipRun:
+			case failedRun:
+				err = failedRun
+			default:
+				panic(fmt.Errorf("unexpected panic: %v [%T]", err, err))
+			}
+		}()
+		testscript.RunT(r, p)
+	}()
+
+	if err != nil {
+		return fmt.Errorf("error running %v in %v\n", fileName, runDir)
+	}
+
+	return nil
+}