refactor package rtree towards testability

7 files changed, 109 insertions, 118 deletions

diff --git a/main.go b/main.go
index 03dc9de..ea34c2e 100644
--- a/main.go
+++ b/main.go
@@ -23,19 +23,10 @@ import (
 	"os"
 	"path/filepath"
 
-	"github.com/majewsky/gofu/pkg/cli"
-	"github.com/majewsky/gofu/pkg/earlyerrors"
 	"github.com/majewsky/gofu/pkg/rtree"
 )
 
 func main() {
-	if len(earlyerrors.Get()) > 0 {
-		for _, msg := range earlyerrors.Get() {
-			cli.Interface.ShowError(msg)
-		}
-		os.Exit(255)
-	}
-
 	os.Exit(execApplet(filepath.Base(os.Args[0]), os.Args[1:], true))
 }
 
diff --git a/pkg/earlyerrors/errors.go b/pkg/earlyerrors/errors.go
deleted file mode 100644
index edde0f8..0000000
--- a/pkg/earlyerrors/errors.go
+++ /dev/null
@@ -1,42 +0,0 @@
-/*******************************************************************************
-*
-* Copyright 2017 Stefan Majewsky <majewsky@gmx.net>
-*
-* This program is free software: you can redistribute it and/or modify it under
-* the terms of the GNU General Public License as published by the Free Software
-* Foundation, either version 3 of the License, or (at your option) any later
-* version.
-*
-* This program is distributed in the hope that it will be useful, but WITHOUT ANY
-* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
-* A PARTICULAR PURPOSE. See the GNU General Public License for more details.
-*
-* You should have received a copy of the GNU General Public License along with
-* this program. If not, see <http://www.gnu.org/licenses/>.
-*
-*******************************************************************************/
-
-//Package earlyerrors can be used to cache errors that occurred during func
-//init(). These errors can then be displayed by func main().
-package earlyerrors
-
-import "fmt"
-
-var errs []string
-
-//Put submits an error message.
-func Put(err string) {
-	if err != "" {
-		errs = append(errs, err)
-	}
-}
-
-//Putf builds and submits an error message.
-func Putf(err string, args ...interface{}) {
-	Put(fmt.Sprintf(err, args...))
-}
-
-//Get returns all collected errors, or an empty slice if there were none.
-func Get() []string {
-	return errs
-}
diff --git a/pkg/rtree/index.go b/pkg/rtree/index.go
index 49ef385..c7d6097 100644
--- a/pkg/rtree/index.go
+++ b/pkg/rtree/index.go
@@ -29,7 +29,6 @@ import (
 	"strings"
 
 	"github.com/majewsky/gofu/pkg/cli"
-	"github.com/majewsky/gofu/pkg/earlyerrors"
 
 	yaml "gopkg.in/yaml.v2"
 )
@@ -39,22 +38,10 @@ type Index struct {
 	Repos []*Repo `yaml:"repos"`
 }
 
-var indexPath string
-
-func init() {
-	homeDir := os.Getenv("HOME")
-	if homeDir == "" {
-		earlyerrors.Put("$HOME is not set (rtree needs the HOME variable to locate its index file)")
-	} else {
-		indexPath = filepath.Join(homeDir, ".rtree/index.yaml")
-	}
-}
-
 //ReadIndex reads the index file.
 func ReadIndex() (*Index, []error) {
 	//read contents of index file
-	path := indexPath
-	buf, err := ioutil.ReadFile(path)
+	buf, err := ioutil.ReadFile(IndexPath)
 	if err != nil {
 		if os.IsNotExist(err) {
 			return &Index{Repos: nil}, nil
@@ -73,7 +60,7 @@ func ReadIndex() (*Index, []error) {
 	var errs []error
 	missing := func(key string, args ...interface{}) {
 		errs = append(errs, fmt.Errorf("read %s: missing \"%s\"",
-			path, fmt.Sprintf(key, args...),
+			IndexPath, fmt.Sprintf(key, args...),
 		))
 	}
 	for idx, repo := range index.Repos {
@@ -110,12 +97,11 @@ func (i *Index) Write() error {
 		return err
 	}
 
-	path := indexPath
-	err = os.MkdirAll(filepath.Dir(path), 0755)
+	err = os.MkdirAll(filepath.Dir(IndexPath), 0755)
 	if err != nil {
 		return err
 	}
-	err = ioutil.WriteFile(path, buf, 0644)
+	err = ioutil.WriteFile(IndexPath, buf, 0644)
 	if err != nil {
 		return err
 	}
diff --git a/pkg/rtree/init.go b/pkg/rtree/init.go
new file mode 100644
index 0000000..1d2dc10
--- /dev/null
+++ b/pkg/rtree/init.go
@@ -0,0 +1,99 @@
+/*******************************************************************************
+*
+* Copyright 2017 Stefan Majewsky <majewsky@gmx.net>
+*
+* This program is free software: you can redistribute it and/or modify it under
+* the terms of the GNU General Public License as published by the Free Software
+* Foundation, either version 3 of the License, or (at your option) any later
+* version.
+*
+* This program is distributed in the hope that it will be useful, but WITHOUT ANY
+* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+* A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License along with
+* this program. If not, see <http://www.gnu.org/licenses/>.
+*
+*******************************************************************************/
+
+package rtree
+
+import (
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+
+	"github.com/majewsky/gofu/pkg/cli"
+)
+
+//RemoteAlias describes an alias that can be used in a Git remote URL (as
+//defined by the "url.<base>.insteadOf" directive in man:git-config(1)).
+type RemoteAlias struct {
+	Alias       string
+	Replacement string
+}
+
+//IndexPath is where the index file is stored.
+var IndexPath string
+
+//RootPath is the directory below which all repositories are located. Its value
+//is $GOPATH/src to match the repository layout created by `go get`.
+var RootPath string
+
+//RemoteAliases is the list of remote aliases that is used by ExpandRemoteURL().
+var RemoteAliases []*RemoteAlias
+
+//Init initializes the global variables of this package to their standard
+//values, unless they are already populated. Unit tests shall set IndexPath,
+//RootPath etc. before calling Exec(), such that this function becomes a no-op
+//when called by Exec().
+//
+//Returns false if initialization failed.
+func Init() bool {
+	ok := true //until shown otherwise
+
+	if IndexPath == "" {
+		homeDir := os.Getenv("HOME")
+		if homeDir == "" {
+			cli.Interface.ShowError("$HOME is not set (rtree needs the HOME variable to locate its index file)")
+			ok = false //but keep going to report all errors at once
+		} else {
+			IndexPath = filepath.Join(homeDir, ".rtree/index.yaml")
+		}
+	}
+
+	if RootPath == "" {
+		gopath := os.Getenv("GOPATH")
+		if gopath == "" {
+			cli.Interface.ShowError("$GOPATH is not set (rtree needs the GOPATH variable to know where to look for and place repos)")
+			ok = false //but keep going to report all errors at once
+		} else {
+			RootPath = filepath.Join(gopath, "src")
+		}
+	}
+
+	if RemoteAliases == nil {
+		out, err := cli.Interface.CaptureStdout(cli.Command{
+			Program: []string{"git", "config", "--global", "-l"},
+		})
+		if err != nil {
+			cli.Interface.ShowError(err.Error())
+			ok = false //but keep going to report all errors at once
+		}
+
+		rx := regexp.MustCompile(`^url\.([^=]+)\.insteadof=(.+)$`)
+		for _, line := range strings.Split(out, "\n") {
+			match := rx.FindStringSubmatch(line)
+			if match == nil {
+				continue
+			}
+			RemoteAliases = append(RemoteAliases, &RemoteAlias{
+				Alias:       match[2],
+				Replacement: match[1],
+			})
+		}
+	}
+
+	return ok
+}
diff --git a/pkg/rtree/main.go b/pkg/rtree/main.go
index 581fa7e..f08126e 100644
--- a/pkg/rtree/main.go
+++ b/pkg/rtree/main.go
@@ -27,6 +27,10 @@ import (
 //Exec executes the rtree applet and does not return. The argument is os.Args
 //minus the leading "rtree" or "gofu rtree".
 func Exec(args []string) int {
+	if !Init() {
+		return 1
+	}
+
 	if len(args) == 0 {
 		return usage()
 	}
diff --git a/pkg/rtree/remote.go b/pkg/rtree/remote.go
index 8f88deb..0c4e880 100644
--- a/pkg/rtree/remote.go
+++ b/pkg/rtree/remote.go
@@ -23,41 +23,8 @@ import (
 	"path/filepath"
 	"regexp"
 	"strings"
-
-	"github.com/majewsky/gofu/pkg/cli"
-	"github.com/majewsky/gofu/pkg/earlyerrors"
 )
 
-//remoteAlias describes an alias that can be used in a Git remote URL (as
-//defined by the "url.<base>.insteadOf" directive in man:git-config(1)).
-type remoteAlias struct {
-	Alias       string
-	Replacement string
-}
-
-var remoteAliases []*remoteAlias
-
-func init() {
-	out, err := cli.Interface.CaptureStdout(cli.Command{
-		Program: []string{"git", "config", "--global", "-l"},
-	})
-	if err != nil {
-		earlyerrors.Put(err.Error())
-	}
-
-	rx := regexp.MustCompile(`^url\.([^=]+)\.insteadof=(.+)$`)
-	for _, line := range strings.Split(out, "\n") {
-		match := rx.FindStringSubmatch(line)
-		if match == nil {
-			continue
-		}
-		remoteAliases = append(remoteAliases, &remoteAlias{
-			Alias:       match[2],
-			Replacement: match[1],
-		})
-	}
-}
-
 //ExpandRemoteURL derive the canonical URL for a given remote by substituting
 //aliases defined in the system-wide and user-global Git config. For example,
 //with
@@ -68,8 +35,8 @@ func init() {
 //
 //and the input "gh:foo/bar", this function returns "git://github.com/foo/bar".
 func ExpandRemoteURL(remoteURL string) string {
-	var best *remoteAlias
-	for _, current := range remoteAliases {
+	var best *RemoteAlias
+	for _, current := range RemoteAliases {
 		if strings.HasPrefix(remoteURL, current.Alias) {
 			if best == nil || len(best.Alias) < len(current.Alias) {
 				best = current
diff --git a/pkg/rtree/repo.go b/pkg/rtree/repo.go
index 636e3a7..790db92 100644
--- a/pkg/rtree/repo.go
+++ b/pkg/rtree/repo.go
@@ -26,22 +26,8 @@ import (
 	"strings"
 
 	"github.com/majewsky/gofu/pkg/cli"
-	"github.com/majewsky/gofu/pkg/earlyerrors"
 )
 
-//RootPath is the directory below which all repositories are located. Its value
-//is $GOPATH/src to match the repository layout created by `go get`.
-var RootPath string
-
-func init() {
-	gopath := os.Getenv("GOPATH")
-	if gopath == "" {
-		earlyerrors.Put("$GOPATH is not set (rtree needs the GOPATH variable to know where to look for and place repos)")
-	} else {
-		RootPath = filepath.Join(gopath, "src")
-	}
-}
-
 //Repo describes the entry for a repository in the index file.
 type Repo struct {
 	//CheckoutPath shall be relative to the RootPath.