Merge pull request #185 from griffindy/dg-add-reset

Add support for libgit2's git_reset.

reset.go

@@ -0,0 +1,26 @@
+package git
+
+/*
+#include <git2.h>
+*/
+import "C"
+import "runtime"
+
+type ResetType int
+
+const (
+	ResetSoft  ResetType = C.GIT_RESET_SOFT
+	ResetMixed ResetType = C.GIT_RESET_MIXED
+	ResetHard  ResetType = C.GIT_RESET_HARD
+)
+
+func (r *Repository) ResetToCommit(commit *Commit, resetType ResetType, opts *CheckoutOpts) error {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+	ret := C.git_reset(r.ptr, commit.gitObject.ptr, C.git_reset_t(resetType), opts.toC())
+
+	if ret < 0 {
+		return MakeGitError(ret)
+	}
+	return nil
+}

reset_test.go

@@ -0,0 +1,45 @@
+package git
+
+import (
+	"io/ioutil"
+	"testing"
+)
+
+func TestResetToCommit(t *testing.T) {
+	repo := createTestRepo(t)
+	seedTestRepo(t, repo)
+	// create commit to reset to
+	commitId, _ := updateReadme(t, repo, "testing reset")
+	// create commit to reset from
+	nextCommitId, _ := updateReadme(t, repo, "will be reset")
+
+	// confirm that we wrote "will be reset" to the readme
+	newBytes, err := ioutil.ReadFile(pathInRepo(repo, "README"))
+	checkFatal(t, err)
+	if string(newBytes) != "will be reset" {
+		t.Fatalf("expected %s to equal 'will be reset'", string(newBytes))
+	}
+
+	// confirm that the head of the repo is the next commit id
+	head, err := repo.Head()
+	checkFatal(t, err)
+	if head.Target().String() != nextCommitId.String() {
+		t.Fatalf(
+			"expected to be at latest commit %s, but was %s",
+			nextCommitId.String(),
+			head.Target().String(),
+		)
+	}
+
+	commitToResetTo, err := repo.LookupCommit(commitId)
+	checkFatal(t, err)
+
+	repo.ResetToCommit(commitToResetTo, ResetHard, &CheckoutOpts{})
+
+	// check that the file now reads "testing reset" like it did before
+	bytes, err := ioutil.ReadFile(pathInRepo(repo, "README"))
+	checkFatal(t, err)
+	if string(bytes) != "testing reset" {
+		t.Fatalf("expected %s to equal 'testing reset'", string(bytes))
+	}
+}