move plumbing from top level package to plumbing (#183)

* plumbing: rename Object -> EncodedObject.

* plumbing/storer: rename ObjectStorer -> EncodedObjectStorer.

* move difftree to plumbing/difftree.

* move diff -> utils/diff

* make Object/Tag/Blob/Tree/Commit/File depend on storer.

* Object and its implementations now depend only on
  storer.EncodedObjectStorer, not git.Repository.
* Tests are decoupled accordingly.

* move Object/Commit/File/Tag/Tree to plumbing/object.

* move Object/Commit/File/Tag/Tree to plumbing/object.
* move checkClose to utils/ioutil.

* move RevListObjects to plumbing/revlist.Objects.

* move DiffTree to plumbing/difftree package.

* rename files with plural nouns to singular

* plumbing/object: add GetBlob/GetCommit/GetTag/GetTree.

1 files changed, 249 insertions, 0 deletions

diff --git a/plumbing/object/file_test.go b/plumbing/object/file_test.go
new file mode 100644
index 0000000..f734455
--- /dev/null
+++ b/plumbing/object/file_test.go
@@ -0,0 +1,249 @@
+package object
+
+import (
+	"io"
+
+	"gopkg.in/src-d/go-git.v4/fixtures"
+	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/storer"
+	"gopkg.in/src-d/go-git.v4/storage/filesystem"
+
+	. "gopkg.in/check.v1"
+)
+
+type FileSuite struct {
+	BaseObjectsSuite
+}
+
+var _ = Suite(&FileSuite{})
+
+type fileIterExpectedEntry struct {
+	Name string
+	Hash string
+}
+
+var fileIterTests = []struct {
+	repo   string // the repo name as in localRepos
+	commit string // the commit to search for the file
+	files  []fileIterExpectedEntry
+}{
+	{"https://github.com/git-fixtures/basic.git", "6ecf0ef2c2dffb796033e5a02219af86ec6584e5", []fileIterExpectedEntry{
+		{".gitignore", "32858aad3c383ed1ff0a0f9bdf231d54a00c9e88"},
+		{"CHANGELOG", "d3ff53e0564a9f87d8e84b6e28e5060e517008aa"},
+		{"LICENSE", "c192bd6a24ea1ab01d78686e417c8bdc7c3d197f"},
+		{"binary.jpg", "d5c0f4ab811897cadf03aec358ae60d21f91c50d"},
+		{"go/example.go", "880cd14280f4b9b6ed3986d6671f907d7cc2a198"},
+		{"json/long.json", "49c6bb89b17060d7b4deacb7b338fcc6ea2352a9"},
+		{"json/short.json", "c8f1d8c61f9da76f4cb49fd86322b6e685dba956"},
+		{"php/crappy.php", "9a48f23120e880dfbe41f7c9b7b708e9ee62a492"},
+		{"vendor/foo.go", "9dea2395f5403188298c1dabe8bdafe562c491e3"},
+	}},
+}
+
+func (s *FileSuite) TestIter(c *C) {
+	for i, t := range fileIterTests {
+		f := fixtures.ByURL(t.repo).One()
+		sto, err := filesystem.NewStorage(f.DotGit())
+		c.Assert(err, IsNil)
+
+		h := plumbing.NewHash(t.commit)
+		commit, err := GetCommit(sto, h)
+		c.Assert(err, IsNil, Commentf("subtest %d: %v (%s)", i, err, t.commit))
+
+		tree, err := commit.Tree()
+		c.Assert(err, IsNil)
+
+		iter := NewFileIter(sto, tree)
+		for k := 0; k < len(t.files); k++ {
+			exp := t.files[k]
+			file, err := iter.Next()
+			c.Assert(err, IsNil, Commentf("subtest %d, iter %d, err=%v", i, k, err))
+			c.Assert(file.Mode.String(), Equals, "-rw-r--r--")
+			c.Assert(file.Hash.IsZero(), Equals, false)
+			c.Assert(file.Hash, Equals, file.ID())
+			c.Assert(file.Name, Equals, exp.Name, Commentf("subtest %d, iter %d, name=%s, expected=%s", i, k, file.Name, exp.Hash))
+			c.Assert(file.Hash.String(), Equals, exp.Hash, Commentf("subtest %d, iter %d, hash=%v, expected=%s", i, k, file.Hash.String(), exp.Hash))
+		}
+		_, err = iter.Next()
+		c.Assert(err, Equals, io.EOF)
+	}
+}
+
+var contentsTests = []struct {
+	repo     string // the repo name as in localRepos
+	commit   string // the commit to search for the file
+	path     string // the path of the file to find
+	contents string // expected contents of the file
+}{
+	{
+		"https://github.com/git-fixtures/basic.git",
+		"b029517f6300c2da0f4b651b8642506cd6aaf45d",
+		".gitignore",
+		`*.class
+
+# Mobile Tools for Java (J2ME)
+.mtj.tmp/
+
+# Package Files #
+*.jar
+*.war
+*.ear
+
+# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
+hs_err_pid*
+`,
+	},
+	{
+		"https://github.com/git-fixtures/basic.git",
+		"6ecf0ef2c2dffb796033e5a02219af86ec6584e5",
+		"CHANGELOG",
+		`Initial changelog
+`,
+	},
+}
+
+func (s *FileSuite) TestContents(c *C) {
+	for i, t := range contentsTests {
+		f := fixtures.ByURL(t.repo).One()
+		sto, err := filesystem.NewStorage(f.DotGit())
+		c.Assert(err, IsNil)
+
+		h := plumbing.NewHash(t.commit)
+		commit, err := GetCommit(sto, h)
+		c.Assert(err, IsNil, Commentf("subtest %d: %v (%s)", i, err, t.commit))
+
+		file, err := commit.File(t.path)
+		c.Assert(err, IsNil)
+		content, err := file.Contents()
+		c.Assert(err, IsNil)
+		c.Assert(content, Equals, t.contents, Commentf(
+			"subtest %d: commit=%s, path=%s", i, t.commit, t.path))
+	}
+}
+
+var linesTests = []struct {
+	repo   string   // the repo name as in localRepos
+	commit string   // the commit to search for the file
+	path   string   // the path of the file to find
+	lines  []string // expected lines in the file
+}{
+	{
+		"https://github.com/git-fixtures/basic.git",
+		"b029517f6300c2da0f4b651b8642506cd6aaf45d",
+		".gitignore",
+		[]string{
+			"*.class",
+			"",
+			"# Mobile Tools for Java (J2ME)",
+			".mtj.tmp/",
+			"",
+			"# Package Files #",
+			"*.jar",
+			"*.war",
+			"*.ear",
+			"",
+			"# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml",
+			"hs_err_pid*",
+		},
+	},
+	{
+		"https://github.com/git-fixtures/basic.git",
+		"6ecf0ef2c2dffb796033e5a02219af86ec6584e5",
+		"CHANGELOG",
+		[]string{
+			"Initial changelog",
+		},
+	},
+}
+
+func (s *FileSuite) TestLines(c *C) {
+	for i, t := range linesTests {
+		f := fixtures.ByURL(t.repo).One()
+		sto, err := filesystem.NewStorage(f.DotGit())
+		c.Assert(err, IsNil)
+
+		h := plumbing.NewHash(t.commit)
+		commit, err := GetCommit(sto, h)
+		c.Assert(err, IsNil, Commentf("subtest %d: %v (%s)", i, err, t.commit))
+
+		file, err := commit.File(t.path)
+		c.Assert(err, IsNil)
+		lines, err := file.Lines()
+		c.Assert(err, IsNil)
+		c.Assert(lines, DeepEquals, t.lines, Commentf(
+			"subtest %d: commit=%s, path=%s", i, t.commit, t.path))
+	}
+}
+
+var ignoreEmptyDirEntriesTests = []struct {
+	repo   string // the repo name as in localRepos
+	commit string // the commit to search for the file
+}{
+	{
+		"https://github.com/cpcs499/Final_Pres_P.git",
+		"70bade703ce556c2c7391a8065c45c943e8b6bc3",
+		// the Final dir in this commit is empty
+	},
+}
+
+// It is difficult to assert that we are ignoring an (empty) dir as even
+// if we don't, no files will be found in it.
+//
+// At least this test has a high chance of panicking if
+// we don't ignore empty dirs.
+func (s *FileSuite) TestIgnoreEmptyDirEntries(c *C) {
+	for i, t := range ignoreEmptyDirEntriesTests {
+		f := fixtures.ByURL(t.repo).One()
+		sto, err := filesystem.NewStorage(f.DotGit())
+		c.Assert(err, IsNil)
+
+		h := plumbing.NewHash(t.commit)
+		commit, err := GetCommit(sto, h)
+		c.Assert(err, IsNil, Commentf("subtest %d: %v (%s)", i, err, t.commit))
+
+		tree, err := commit.Tree()
+		c.Assert(err, IsNil)
+
+		iter := tree.Files()
+		defer iter.Close()
+		for file, err := iter.Next(); err == nil; file, err = iter.Next() {
+			_, _ = file.Contents()
+			// this would probably panic if we are not ignoring empty dirs
+		}
+	}
+}
+
+func (s *FileSuite) TestFileIter(c *C) {
+	hash := plumbing.NewHash("1669dce138d9b841a518c64b10914d88f5e488ea")
+	commit, err := GetCommit(s.Storer, hash)
+	c.Assert(err, IsNil)
+
+	tree, err := commit.Tree()
+	c.Assert(err, IsNil)
+
+	expected := []string{
+		".gitignore",
+		"CHANGELOG",
+		"LICENSE",
+		"binary.jpg",
+	}
+
+	var count int
+	i := tree.Files()
+	i.ForEach(func(f *File) error {
+		c.Assert(f.Name, Equals, expected[count])
+		count++
+		return nil
+	})
+
+	c.Assert(count, Equals, 4)
+
+	count = 0
+	i = tree.Files()
+	i.ForEach(func(f *File) error {
+		count++
+		return storer.ErrStop
+	})
+
+	c.Assert(count, Equals, 1)
+}