Add fetch

Also add a test. Man, this took forever to implement.

commit_test.go

@@ -13,7 +13,7 @@ import (
 	"gotest.tools/v3/assert"
 )
 
-func prepareFixture(t *testing.T, name string) string {
+func PrepareFixture(t *testing.T, name string) string {
 	newRepoPath, err := ioutil.TempDir(os.TempDir(), name)
 	assert.NilError(t, err)
 
@@ -28,7 +28,7 @@ func prepareFixture(t *testing.T, name string) string {
 }
 
 func Test_NoChanges(t *testing.T) {
-	repoPath := prepareFixture(t, "no_changes")
+	repoPath := PrepareFixture(t, "no_changes")
 
 	err := commit(repoPath)
 	assert.NilError(t, err)
@@ -43,7 +43,7 @@ func Test_NoChanges(t *testing.T) {
 }
 
 func Test_NewFile(t *testing.T) {
-	repoPath := prepareFixture(t, "new_file")
+	repoPath := PrepareFixture(t, "new_file")
 
 	err := commit(repoPath)
 	assert.NilError(t, err)
@@ -58,7 +58,7 @@ func Test_NewFile(t *testing.T) {
 }
 
 func Test_OneFileChange(t *testing.T) {
-	repoPath := prepareFixture(t, "one_file_change")
+	repoPath := PrepareFixture(t, "one_file_change")
 
 	err := commit(repoPath)
 	assert.NilError(t, err)
@@ -73,7 +73,7 @@ func Test_OneFileChange(t *testing.T) {
 }
 
 func Test_MultipleFileChange(t *testing.T) {
-	repoPath := prepareFixture(t, "multiple_file_change")
+	repoPath := PrepareFixture(t, "multiple_file_change")
 
 	err := commit(repoPath)
 	assert.NilError(t, err)

fetch.go

@@ -0,0 +1,29 @@
+package main
+
+import (
+	"github.com/ztrue/tracerr"
+	"gopkg.in/src-d/go-git.v4"
+)
+
+func fetch(repoPath string) error {
+	r, err := git.PlainOpen(repoPath)
+	if err != nil {
+		return tracerr.Wrap(err)
+	}
+
+	remotes, err := r.Remotes()
+	if err != nil {
+		return tracerr.Wrap(err)
+	}
+
+	for _, remote := range remotes {
+		remoteName := remote.Config().Name
+
+		err, _, errB := GitCommand(repoPath, []string{"fetch", remoteName})
+		if err != nil {
+			return tracerr.Errorf("Remote: %s %s %w", remoteName, errB.Bytes(), err)
+		}
+	}
+
+	return nil
+}

fetch_test.go

@@ -0,0 +1,69 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	cp "github.com/otiai10/copy"
+	"gopkg.in/src-d/go-git.v4"
+	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gotest.tools/v3/assert"
+)
+
+func PrepareMultiFixtures(t *testing.T, name string, deps []string) string {
+	newTestDataPath, err := ioutil.TempDir(os.TempDir(), "mutli_fixture")
+	assert.NilError(t, err)
+
+	for _, name := range deps {
+		fixturePath := filepath.Join("testdata", name)
+		newPath := filepath.Join(newTestDataPath, name)
+		err = cp.Copy(fixturePath, newPath)
+		assert.NilError(t, err)
+
+		err = os.Rename(filepath.Join(newPath, ".gitted"), filepath.Join(newPath, ".git"))
+		assert.NilError(t, err)
+	}
+
+	newRepoPath := PrepareFixture(t, name)
+	FixFixtureGitConfig(t, newRepoPath, newTestDataPath)
+
+	return newRepoPath
+}
+
+func FixFixtureGitConfig(t *testing.T, newRepoPath string, testDataPath string) {
+	// Fix remote paths
+	dotGitPath := filepath.Join(newRepoPath, ".git")
+	gitConfigFilePath := filepath.Join(dotGitPath, "config")
+	input, err := ioutil.ReadFile(gitConfigFilePath)
+	assert.NilError(t, err)
+
+	output := bytes.Replace(input, []byte("$TESTDATA$"), []byte(testDataPath), -1)
+
+	err = ioutil.WriteFile(gitConfigFilePath, output, 0666)
+	assert.NilError(t, err)
+}
+
+func Test_SimpleFetch(t *testing.T) {
+	repoPath := PrepareMultiFixtures(t, "simple_fetch", []string{"multiple_file_change"})
+	fmt.Println(repoPath)
+
+	err := fetch(repoPath)
+	assert.NilError(t, err)
+
+	r, err := git.PlainOpen(repoPath)
+	assert.NilError(t, err)
+
+	head, err := r.Head()
+	assert.NilError(t, err)
+
+	assert.Equal(t, head.Hash(), plumbing.NewHash("28cc969d97ddb7640f5e1428bbc8f2947d1ffd57"))
+
+	ref, err := r.Reference(plumbing.NewRemoteReferenceName("origin1", "master"), true)
+	assert.NilError(t, err)
+
+	assert.Equal(t, ref.Hash(), plumbing.NewHash("7058b6b292ee3d1382670334b5f29570a1117ef1"))
+}

testdata/simple_fetch/.gitted/HEAD

@@ -0,0 +1 @@
+ref: refs/heads/master

testdata/simple_fetch/.gitted/config

@@ -0,0 +1,8 @@
+[core]
+	repositoryformatversion = 0
+	filemode = true
+	bare = false
+	logallrefupdates = true
+[remote "origin1"]
+	url = file://$TESTDATA$/multiple_file_change/.git
+	fetch = +refs/heads/*:refs/remotes/origin1/*

testdata/simple_fetch/.gitted/description

@@ -0,0 +1 @@
+Unnamed repository; edit this file 'description' to name the repository.

testdata/simple_fetch/.gitted/packed-refs

@@ -0,0 +1,2 @@
+# pack-refs with: peeled fully-peeled sorted 
+28cc969d97ddb7640f5e1428bbc8f2947d1ffd57 refs/heads/master

testdata/simple_fetch/1.md

@@ -0,0 +1 @@
+1