Add beginnings of new cr command

go/src/infra/tools/cr/cmd/firstrun/firstrun_test.go

Index: go/src/infra/tools/cr/cmd/firstrun/firstrun_test.go
diff --git a/go/src/infra/tools/cr/cmd/firstrun/firstrun_test.go b/go/src/infra/tools/cr/cmd/firstrun/firstrun_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..c21938c3c072969895931e41cdc55e51e4e7f4fd
--- /dev/null
+++ b/go/src/infra/tools/cr/cmd/firstrun/firstrun_test.go
@@ -0,0 +1,119 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// OS-agnostic helper functions which are called from run().
+
+package firstrun
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+type fakeFileInfo struct {
+	name    string
+	size    int64
+	mode    os.FileMode
+	modTime time.Time
+	isDir   bool
+}
+
+func (f fakeFileInfo) Name() string       { return f.name }
+func (f fakeFileInfo) Size() int64        { return f.size }
+func (f fakeFileInfo) Mode() os.FileMode  { return f.mode }
+func (f fakeFileInfo) ModTime() time.Time { return f.modTime }
+func (f fakeFileInfo) IsDir() bool        { return f.isDir }
+func (f fakeFileInfo) Sys() interface{}   { return nil }
+
+func TestCheckNotInstalled(t *testing.T) {
+	t.Parallel()
+	Convey("When checking that cr isn't already installed", t, func() {
+		Convey("an empty $PATH results in an error", func() {
+			getenv = func(s string) string { return "" }
+			path, err := firstrunCheckNotInstalled()
+			So(path, ShouldEqual, "")
+			So(err, ShouldNotBeNil)
+		})
+
+		Convey("paths not ending in cr/bin are ignored", func() {
+			getenv = func(s string) string {
+				paths := []string{
+					filepath.Join("foo", "bar"),
+					filepath.Join("foo", "cr", "bin", "bar"),
+				}
+				return strings.Join(paths, string(os.PathListSeparator))
+			}
+			path, err := firstrunCheckNotInstalled()
+			So(path, ShouldEqual, "")
+			So(err, ShouldBeNil)
+		})
+
+		Convey("multiple candidates are all checked", func() {
+			getenv = func(s string) string {
+				paths := []string{
+					filepath.Join("foo", "cr", "bin"),
+					filepath.Join("foo", "bar", "cr", "bin"),
+				}
+				return strings.Join(paths, string(os.PathListSeparator))
+			}
+
+			Convey("and missing executables are handled", func() {
+				stat = func(s string) (os.FileInfo, error) {
+					return nil, os.ErrNotExist
+				}
+				path, err := firstrunCheckNotInstalled()
+				So(path, ShouldEqual, "")
+				So(err, ShouldBeNil)
+			})
+
+			Convey("and non-executables are ignored", func() {
+				stat = func(s string) (os.FileInfo, error) {
+					return fakeFileInfo{executableName, 64, 0666, time.Now(), false}, nil
+				}
+				path, err := firstrunCheckNotInstalled()
+				So(err, ShouldBeNil)
+				So(path, ShouldEqual, "")
+			})
+
+			Convey("and the only executable is returned", func() {
+				stat = func(s string) (os.FileInfo, error) {
+					if strings.Contains(s, "bar") {
+						return fakeFileInfo{executableName, 64, 0777, time.Now(), false}, nil
+					}
+					return fakeFileInfo{executableName, 64, 0666, time.Now(), false}, nil
+				}
+				path, err := firstrunCheckNotInstalled()
+				So(path, ShouldEqual, filepath.Join("foo", "bar", "cr", "bin", executableName))
+				So(err, ShouldBeNil)
+			})
+
+			Convey("and the first executable is returned", func() {
+				stat = func(s string) (os.FileInfo, error) {
+					return fakeFileInfo{executableName, 64, 0777, time.Now(), false}, nil
+				}
+				path, err := firstrunCheckNotInstalled()
+				So(path, ShouldEqual, filepath.Join("foo", "cr", "bin", executableName))
+				So(err, ShouldBeNil)
+			})
+
+			Convey("and errors are propagated forward", func() {
+				stat = func(s string) (os.FileInfo, error) {
+					if strings.Contains(s, "bar") {
+						return fakeFileInfo{executableName, 64, 0666, time.Now(), false}, nil
+					}
+					return nil, errors.New("some crazy error")
+				}
+				path, err := firstrunCheckNotInstalled()
+				So(path, ShouldEqual, "")
+				So(err, ShouldResemble, errors.New("some crazy error"))
+			})
+		})
+	})
+}