gather test coverage from gitaly-git2gosmh-git2go-test-coverage

Gathers test coverage from gitaly-git2go by running functionality
in-process as well as in a subprocess.

24 files changed, 294 insertions, 173 deletions

diff --git a/cmd/gitaly-git2go/commit.go b/cmd/gitaly-git2go/command/commit.go
index 3d8ac4c7f..82c388e20 100644
--- a/cmd/gitaly-git2go/commit.go
+++ b/cmd/gitaly-git2go/command/commit.go
@@ -1,13 +1,13 @@
 // +build static,system_libgit2
 
-package main
+package command
 
 import (
 	"context"
 	"flag"
 	"io"
 
-	"gitlab.com/gitlab-org/gitaly/cmd/gitaly-git2go/commit"
+	"gitlab.com/gitlab-org/gitaly/cmd/gitaly-git2go/command/commit"
 )
 
 type commitSubcommand struct{}
diff --git a/cmd/gitaly-git2go/commit/change_file_mode.go b/cmd/gitaly-git2go/command/commit/change_file_mode.go
index 17200ee37..17200ee37 100644
--- a/cmd/gitaly-git2go/commit/change_file_mode.go
+++ b/cmd/gitaly-git2go/command/commit/change_file_mode.go
diff --git a/cmd/gitaly-git2go/commit/commit.go b/cmd/gitaly-git2go/command/commit/commit.go
index 90862e1a7..8d00b7d04 100644
--- a/cmd/gitaly-git2go/commit/commit.go
+++ b/cmd/gitaly-git2go/command/commit/commit.go
@@ -8,6 +8,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"log"
 
 	git "github.com/libgit2/git2go/v30"
 	"gitlab.com/gitlab-org/gitaly/internal/git2go"
@@ -62,6 +63,14 @@ func commit(ctx context.Context, params git2go.CommitParams) (string, error) {
 		}
 	}
 
+	if false {
+		log.Printf("never covered")
+	}
+
+	if true {
+		log.Printf("covered")
+	}
+
 	for _, action := range params.Actions {
 		if err := apply(action, repo, index); err != nil {
 			return "", fmt.Errorf("apply action %T: %w", action, err)
diff --git a/cmd/gitaly-git2go/commit/create_directory.go b/cmd/gitaly-git2go/command/commit/create_directory.go
index c7059c0a3..c7059c0a3 100644
--- a/cmd/gitaly-git2go/commit/create_directory.go
+++ b/cmd/gitaly-git2go/command/commit/create_directory.go
diff --git a/cmd/gitaly-git2go/commit/create_file.go b/cmd/gitaly-git2go/command/commit/create_file.go
index 62bc6f61b..62bc6f61b 100644
--- a/cmd/gitaly-git2go/commit/create_file.go
+++ b/cmd/gitaly-git2go/command/commit/create_file.go
diff --git a/cmd/gitaly-git2go/commit/delete_file.go b/cmd/gitaly-git2go/command/commit/delete_file.go
index 0c9df3be6..0c9df3be6 100644
--- a/cmd/gitaly-git2go/commit/delete_file.go
+++ b/cmd/gitaly-git2go/command/commit/delete_file.go
diff --git a/cmd/gitaly-git2go/commit/move_file.go b/cmd/gitaly-git2go/command/commit/move_file.go
index e9c115083..e9c115083 100644
--- a/cmd/gitaly-git2go/commit/move_file.go
+++ b/cmd/gitaly-git2go/command/commit/move_file.go
diff --git a/cmd/gitaly-git2go/commit/update_file.go b/cmd/gitaly-git2go/command/commit/update_file.go
index 0bf6e7514..0bf6e7514 100644
--- a/cmd/gitaly-git2go/commit/update_file.go
+++ b/cmd/gitaly-git2go/command/commit/update_file.go
diff --git a/cmd/gitaly-git2go/commit/validate.go b/cmd/gitaly-git2go/command/commit/validate.go
index 8854cdbbe..8854cdbbe 100644
--- a/cmd/gitaly-git2go/commit/validate.go
+++ b/cmd/gitaly-git2go/command/commit/validate.go
diff --git a/cmd/gitaly-git2go/conflicts.go b/cmd/gitaly-git2go/command/conflicts.go
index 85f3c5a9c..5ae3fb71e 100644
--- a/cmd/gitaly-git2go/conflicts.go
+++ b/cmd/gitaly-git2go/command/conflicts.go
@@ -1,6 +1,6 @@
 // +build static,system_libgit2
 
-package main
+package command
 
 import (
 	"context"
diff --git a/cmd/gitaly-git2go/conflicts_test.go b/cmd/gitaly-git2go/command/conflicts_test.go
index 4cef16c12..5d81dc2b7 100644
--- a/cmd/gitaly-git2go/conflicts_test.go
+++ b/cmd/gitaly-git2go/command/conflicts_test.go
@@ -1,6 +1,6 @@
 // +build static,system_libgit2
 
-package main
+package command
 
 import (
 	"testing"
diff --git a/cmd/gitaly-git2go/command/main.go b/cmd/gitaly-git2go/command/main.go
new file mode 100644
index 000000000..15a07851b
--- /dev/null
+++ b/cmd/gitaly-git2go/command/main.go
@@ -0,0 +1,69 @@
+// +build static,system_libgit2
+
+package command
+
+import (
+	"context"
+	"errors"
+	"flag"
+	"fmt"
+	"io"
+)
+
+// Process encapsulates process global state.
+type Process struct {
+	Args   []string
+	Stdin  io.Reader
+	Stdout io.Writer
+	Stderr io.Writer
+}
+
+type subcmd interface {
+	Flags() *flag.FlagSet
+	Run(ctx context.Context, stdin io.Reader, stdout io.Writer) error
+}
+
+var subcommands = map[string]subcmd{
+	"conflicts": &conflictsSubcommand{},
+	"commit":    commitSubcommand{},
+	"merge":     &mergeSubcommand{},
+	"revert":    &revertSubcommand{},
+}
+
+const programName = "gitaly-git2go"
+
+func Main(p Process) int {
+	if err := main(p); err != nil {
+		fmt.Fprintf(p.Stderr, err.Error()+"\n")
+		return 1
+	}
+
+	return 0
+}
+
+func main(p Process) error {
+	flags := flag.NewFlagSet(programName, flag.ExitOnError)
+	flags.Parse(p.Args)
+
+	if flags.NArg() < 2 {
+		return errors.New("missing subcommand")
+	}
+
+	subcmd, ok := subcommands[flags.Arg(1)]
+	if !ok {
+		return fmt.Errorf("unknown subcommand: %q", flags.Arg(1))
+	}
+
+	subcmdFlags := subcmd.Flags()
+	subcmdFlags.Parse(flags.Args()[2:])
+
+	if subcmdFlags.NArg() != 0 {
+		return fmt.Errorf("%s: trailing arguments", subcmdFlags.Name())
+	}
+
+	if err := subcmd.Run(context.Background(), p.Stdin, p.Stdout); err != nil {
+		return fmt.Errorf("%s: %s", subcmdFlags.Name(), err)
+	}
+
+	return nil
+}
diff --git a/cmd/gitaly-git2go/main_test.go b/cmd/gitaly-git2go/command/main_test.go
index e9552633b..9b366a67e 100644
--- a/cmd/gitaly-git2go/main_test.go
+++ b/cmd/gitaly-git2go/command/main_test.go
@@ -1,6 +1,6 @@
 // +build static,system_libgit2
 
-package main
+package command
 
 import (
 	"os"
diff --git a/cmd/gitaly-git2go/merge.go b/cmd/gitaly-git2go/command/merge.go
index 5a9f10a73..c0d9b7b32 100644
--- a/cmd/gitaly-git2go/merge.go
+++ b/cmd/gitaly-git2go/command/merge.go
@@ -1,6 +1,6 @@
 // +build static,system_libgit2
 
-package main
+package command
 
 import (
 	"context"
diff --git a/cmd/gitaly-git2go/merge_test.go b/cmd/gitaly-git2go/command/merge_test.go
index c201560a0..c77d4cb0f 100644
--- a/cmd/gitaly-git2go/merge_test.go
+++ b/cmd/gitaly-git2go/command/merge_test.go
@@ -1,6 +1,6 @@
 // +build static,system_libgit2
 
-package main
+package command
 
 import (
 	"testing"
diff --git a/cmd/gitaly-git2go/revert.go b/cmd/gitaly-git2go/command/revert.go
index 110d50309..c18b147af 100644
--- a/cmd/gitaly-git2go/revert.go
+++ b/cmd/gitaly-git2go/command/revert.go
@@ -1,6 +1,6 @@
 // +build static,system_libgit2
 
-package main
+package command
 
 import (
 	"context"
diff --git a/cmd/gitaly-git2go/revert_test.go b/cmd/gitaly-git2go/command/revert_test.go
index 6c62b9f93..555d2fa25 100644
--- a/cmd/gitaly-git2go/revert_test.go
+++ b/cmd/gitaly-git2go/command/revert_test.go
@@ -1,6 +1,6 @@
 // +build static,system_libgit2
 
-package main
+package command
 
 import (
 	"testing"
diff --git a/cmd/gitaly-git2go/util.go b/cmd/gitaly-git2go/command/util.go
index a315c5f3a..f5a8937dd 100644
--- a/cmd/gitaly-git2go/util.go
+++ b/cmd/gitaly-git2go/command/util.go
@@ -1,6 +1,6 @@
 // +build static,system_libgit2
 
-package main
+package command
 
 import (
 	"fmt"
diff --git a/cmd/gitaly-git2go/main.go b/cmd/gitaly-git2go/main.go
index cfe5e5cde..aa13c1506 100644
--- a/cmd/gitaly-git2go/main.go
+++ b/cmd/gitaly-git2go/main.go
@@ -1,55 +1,17 @@
 // +build static,system_libgit2
-
 package main
 
 import (
-	"context"
-	"flag"
-	"fmt"
-	"io"
 	"os"
-)
-
-type subcmd interface {
-	Flags() *flag.FlagSet
-	Run(ctx context.Context, stdin io.Reader, stdout io.Writer) error
-}
-
-var subcommands = map[string]subcmd{
-	"conflicts": &conflictsSubcommand{},
-	"commit":    commitSubcommand{},
-	"merge":     &mergeSubcommand{},
-	"revert":    &revertSubcommand{},
-}
-
-const programName = "gitaly-git2go"
 
-func fatalf(format string, args ...interface{}) {
-	fmt.Fprintf(os.Stderr, format+"\n", args...)
-	os.Exit(1)
-}
+	"gitlab.com/gitlab-org/gitaly/cmd/gitaly-git2go/command"
+)
 
 func main() {
-	flags := flag.NewFlagSet(programName, flag.ExitOnError)
-	flags.Parse(os.Args)
-
-	if flags.NArg() < 2 {
-		fatalf("missing subcommand")
-	}
-
-	subcmd, ok := subcommands[flags.Arg(1)]
-	if !ok {
-		fatalf("unknown subcommand: %q", flags.Arg(1))
-	}
-
-	subcmdFlags := subcmd.Flags()
-	subcmdFlags.Parse(flags.Args()[2:])
-
-	if subcmdFlags.NArg() != 0 {
-		fatalf("%s: trailing arguments", subcmdFlags.Name())
-	}
-
-	if err := subcmd.Run(context.Background(), os.Stdin, os.Stdout); err != nil {
-		fatalf("%s: %s", subcmdFlags.Name(), err)
-	}
+	os.Exit(command.Main(command.Process{
+		Args:   os.Args,
+		Stdin:  os.Stdin,
+		Stdout: os.Stdout,
+		Stderr: os.Stderr,
+	}))
 }
diff --git a/internal/git2go/commit.go b/internal/git2go/commit.go
index ee24862d9..5b8fc430e 100644
--- a/internal/git2go/commit.go
+++ b/internal/git2go/commit.go
@@ -55,7 +55,7 @@ func (b Executor) Commit(ctx context.Context, params CommitParams) (string, erro
 		return "", err
 	}
 
-	output, err := run(ctx, b.binaryPath, input, "commit")
+	output, err := b.run(ctx, b.binaryPath, input, "commit")
 	if err != nil {
 		return "", err
 	}
diff --git a/internal/git2go/commit_test.go b/internal/git2go/commit_test.go
index 6a1eea7a0..85df5e689 100644
--- a/internal/git2go/commit_test.go
+++ b/internal/git2go/commit_test.go
@@ -1,12 +1,10 @@
-package git2go
+package git2go_test
 
 import (
 	"bytes"
 	"context"
 	"errors"
 	"fmt"
-	"os"
-	"path/filepath"
 	"strconv"
 	"strings"
 	"testing"
@@ -14,31 +12,27 @@ import (
 
 	"github.com/stretchr/testify/require"
 	"gitlab.com/gitlab-org/gitaly/internal/git"
-	"gitlab.com/gitlab-org/gitaly/internal/gitaly/config"
+	"gitlab.com/gitlab-org/gitaly/internal/git2go"
 	"gitlab.com/gitlab-org/gitaly/internal/testhelper"
 )
 
-func TestMain(m *testing.M) {
-	testhelper.Configure()
-	testhelper.ConfigureGitalyGit2Go()
-	os.Exit(m.Run())
-}
-
 type commit struct {
 	Parent    string
-	Author    Signature
-	Committer Signature
+	Author    git2go.Signature
+	Committer git2go.Signature
 	Message   string
 }
 
-func TestExecutor_Commit(t *testing.T) {
+func TestExecutor_Commit(t *testing.T) { testExecutors(t, testExecutor_Commit) }
+
+func testExecutor_Commit(t *testing.T, executor git2go.Executor) {
 	const (
 		DefaultMode    = "100644"
 		ExecutableMode = "100755"
 	)
 
 	type step struct {
-		actions     []Action
+		actions     []git2go.Action
 		error       error
 		treeEntries []testhelper.TreeEntry
 	}
@@ -57,8 +51,6 @@ func TestExecutor_Commit(t *testing.T) {
 	updatedFile, err := repo.WriteBlob(ctx, "file", bytes.NewBufferString("updated"))
 	require.NoError(t, err)
 
-	executor := New(filepath.Join(config.Config.BinDir, "gitaly-git2go"))
-
 	for _, tc := range []struct {
 		desc  string
 		steps []step
@@ -67,8 +59,8 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "create directory",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateDirectory{Path: "directory"},
+					actions: []git2go.Action{
+						git2go.CreateDirectory{Path: "directory"},
 					},
 					treeEntries: []testhelper.TreeEntry{
 						{Mode: DefaultMode, Path: "directory/.gitkeep"},
@@ -80,11 +72,11 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "create directory created duplicate",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateDirectory{Path: "directory"},
-						CreateDirectory{Path: "directory"},
+					actions: []git2go.Action{
+						git2go.CreateDirectory{Path: "directory"},
+						git2go.CreateDirectory{Path: "directory"},
 					},
-					error: DirectoryExistsError("directory"),
+					error: git2go.DirectoryExistsError("directory"),
 				},
 			},
 		},
@@ -92,18 +84,18 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "create directory existing duplicate",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateDirectory{Path: "directory"},
+					actions: []git2go.Action{
+						git2go.CreateDirectory{Path: "directory"},
 					},
 					treeEntries: []testhelper.TreeEntry{
 						{Mode: DefaultMode, Path: "directory/.gitkeep"},
 					},
 				},
 				{
-					actions: []Action{
-						CreateDirectory{Path: "directory"},
+					actions: []git2go.Action{
+						git2go.CreateDirectory{Path: "directory"},
 					},
-					error: DirectoryExistsError("directory"),
+					error: git2go.DirectoryExistsError("directory"),
 				},
 			},
 		},
@@ -111,18 +103,18 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "create directory with a files name",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateFile{Path: "file", OID: originalFile},
+					actions: []git2go.Action{
+						git2go.CreateFile{Path: "file", OID: originalFile},
 					},
 					treeEntries: []testhelper.TreeEntry{
 						{Mode: DefaultMode, Path: "file", Content: "original"},
 					},
 				},
 				{
-					actions: []Action{
-						CreateDirectory{Path: "file"},
+					actions: []git2go.Action{
+						git2go.CreateDirectory{Path: "file"},
 					},
-					error: FileExistsError("file"),
+					error: git2go.FileExistsError("file"),
 				},
 			},
 		},
@@ -130,8 +122,8 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "create file",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateFile{Path: "file", OID: originalFile},
+					actions: []git2go.Action{
+						git2go.CreateFile{Path: "file", OID: originalFile},
 					},
 					treeEntries: []testhelper.TreeEntry{
 						{Mode: DefaultMode, Path: "file", Content: "original"},
@@ -143,11 +135,11 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "create duplicate file",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateFile{Path: "file", OID: originalFile},
-						CreateFile{Path: "file", OID: updatedFile},
+					actions: []git2go.Action{
+						git2go.CreateFile{Path: "file", OID: originalFile},
+						git2go.CreateFile{Path: "file", OID: updatedFile},
 					},
-					error: FileExistsError("file"),
+					error: git2go.FileExistsError("file"),
 				},
 			},
 		},
@@ -155,9 +147,9 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "create file overwrites directory",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateDirectory{Path: "directory"},
-						CreateFile{Path: "directory", OID: originalFile},
+					actions: []git2go.Action{
+						git2go.CreateDirectory{Path: "directory"},
+						git2go.CreateFile{Path: "directory", OID: originalFile},
 					},
 					treeEntries: []testhelper.TreeEntry{
 						{Mode: DefaultMode, Path: "directory", Content: "original"},
@@ -169,9 +161,9 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "update created file",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateFile{Path: "file", OID: originalFile},
-						UpdateFile{Path: "file", OID: updatedFile},
+					actions: []git2go.Action{
+						git2go.CreateFile{Path: "file", OID: originalFile},
+						git2go.UpdateFile{Path: "file", OID: updatedFile},
 					},
 					treeEntries: []testhelper.TreeEntry{
 						{Mode: DefaultMode, Path: "file", Content: "updated"},
@@ -183,16 +175,16 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "update existing file",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateFile{Path: "file", OID: originalFile},
+					actions: []git2go.Action{
+						git2go.CreateFile{Path: "file", OID: originalFile},
 					},
 					treeEntries: []testhelper.TreeEntry{
 						{Mode: DefaultMode, Path: "file", Content: "original"},
 					},
 				},
 				{
-					actions: []Action{
-						UpdateFile{Path: "file", OID: updatedFile},
+					actions: []git2go.Action{
+						git2go.UpdateFile{Path: "file", OID: updatedFile},
 					},
 					treeEntries: []testhelper.TreeEntry{
 						{Mode: DefaultMode, Path: "file", Content: "updated"},
@@ -204,10 +196,10 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "update non-existing file",
 			steps: []step{
 				{
-					actions: []Action{
-						UpdateFile{Path: "non-existing", OID: updatedFile},
+					actions: []git2go.Action{
+						git2go.UpdateFile{Path: "non-existing", OID: updatedFile},
 					},
-					error: FileNotFoundError("non-existing"),
+					error: git2go.FileNotFoundError("non-existing"),
 				},
 			},
 		},
@@ -215,9 +207,9 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "move created file",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateFile{Path: "original-file", OID: originalFile},
-						MoveFile{Path: "original-file", NewPath: "moved-file", OID: originalFile},
+					actions: []git2go.Action{
+						git2go.CreateFile{Path: "original-file", OID: originalFile},
+						git2go.MoveFile{Path: "original-file", NewPath: "moved-file", OID: originalFile},
 					},
 					treeEntries: []testhelper.TreeEntry{
 						{Mode: DefaultMode, Path: "moved-file", Content: "original"},
@@ -229,11 +221,11 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "moving directory fails",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateDirectory{Path: "directory"},
-						MoveFile{Path: "directory", NewPath: "moved-directory"},
+					actions: []git2go.Action{
+						git2go.CreateDirectory{Path: "directory"},
+						git2go.MoveFile{Path: "directory", NewPath: "moved-directory"},
 					},
-					error: FileNotFoundError("directory"),
+					error: git2go.FileNotFoundError("directory"),
 				},
 			},
 		},
@@ -241,16 +233,16 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "move file inferring content",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateFile{Path: "original-file", OID: originalFile},
+					actions: []git2go.Action{
+						git2go.CreateFile{Path: "original-file", OID: originalFile},
 					},
 					treeEntries: []testhelper.TreeEntry{
 						{Mode: DefaultMode, Path: "original-file", Content: "original"},
 					},
 				},
 				{
-					actions: []Action{
-						MoveFile{Path: "original-file", NewPath: "moved-file"},
+					actions: []git2go.Action{
+						git2go.MoveFile{Path: "original-file", NewPath: "moved-file"},
 					},
 					treeEntries: []testhelper.TreeEntry{
 						{Mode: DefaultMode, Path: "moved-file", Content: "original"},
@@ -262,10 +254,10 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "move file with non-existing source",
 			steps: []step{
 				{
-					actions: []Action{
-						MoveFile{Path: "non-existing", NewPath: "destination-file"},
+					actions: []git2go.Action{
+						git2go.MoveFile{Path: "non-existing", NewPath: "destination-file"},
 					},
-					error: FileNotFoundError("non-existing"),
+					error: git2go.FileNotFoundError("non-existing"),
 				},
 			},
 		},
@@ -273,12 +265,12 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "move file with already existing destination file",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateFile{Path: "source-file", OID: originalFile},
-						CreateFile{Path: "already-existing", OID: updatedFile},
-						MoveFile{Path: "source-file", NewPath: "already-existing"},
+					actions: []git2go.Action{
+						git2go.CreateFile{Path: "source-file", OID: originalFile},
+						git2go.CreateFile{Path: "already-existing", OID: updatedFile},
+						git2go.MoveFile{Path: "source-file", NewPath: "already-existing"},
 					},
-					error: FileExistsError("already-existing"),
+					error: git2go.FileExistsError("already-existing"),
 				},
 			},
 		},
@@ -288,10 +280,10 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "move file with already existing destination directory",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateFile{Path: "file", OID: originalFile},
-						CreateDirectory{Path: "already-existing"},
-						MoveFile{Path: "file", NewPath: "already-existing"},
+					actions: []git2go.Action{
+						git2go.CreateFile{Path: "file", OID: originalFile},
+						git2go.CreateDirectory{Path: "already-existing"},
+						git2go.MoveFile{Path: "file", NewPath: "already-existing"},
 					},
 					treeEntries: []testhelper.TreeEntry{
 						{Mode: DefaultMode, Path: "already-existing", Content: "original"},
@@ -303,16 +295,16 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "move file providing content",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateFile{Path: "original-file", OID: originalFile},
+					actions: []git2go.Action{
+						git2go.CreateFile{Path: "original-file", OID: originalFile},
 					},
 					treeEntries: []testhelper.TreeEntry{
 						{Mode: DefaultMode, Path: "original-file", Content: "original"},
 					},
 				},
 				{
-					actions: []Action{
-						MoveFile{Path: "original-file", NewPath: "moved-file", OID: updatedFile},
+					actions: []git2go.Action{
+						git2go.MoveFile{Path: "original-file", NewPath: "moved-file", OID: updatedFile},
 					},
 					treeEntries: []testhelper.TreeEntry{
 						{Mode: DefaultMode, Path: "moved-file", Content: "updated"},
@@ -324,10 +316,10 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "mark non-existing file executable",
 			steps: []step{
 				{
-					actions: []Action{
-						ChangeFileMode{Path: "non-existing"},
+					actions: []git2go.Action{
+						git2go.ChangeFileMode{Path: "non-existing"},
 					},
-					error: FileNotFoundError("non-existing"),
+					error: git2go.FileNotFoundError("non-existing"),
 				},
 			},
 		},
@@ -335,17 +327,17 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "mark executable file executable",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateFile{Path: "file-1", OID: originalFile},
-						ChangeFileMode{Path: "file-1", ExecutableMode: true},
+					actions: []git2go.Action{
+						git2go.CreateFile{Path: "file-1", OID: originalFile},
+						git2go.ChangeFileMode{Path: "file-1", ExecutableMode: true},
 					},
 					treeEntries: []testhelper.TreeEntry{
 						{Mode: ExecutableMode, Path: "file-1", Content: "original"},
 					},
 				},
 				{
-					actions: []Action{
-						ChangeFileMode{Path: "file-1", ExecutableMode: true},
+					actions: []git2go.Action{
+						git2go.ChangeFileMode{Path: "file-1", ExecutableMode: true},
 					},
 					treeEntries: []testhelper.TreeEntry{
 						{Mode: ExecutableMode, Path: "file-1", Content: "original"},
@@ -357,9 +349,9 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "mark created file executable",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateFile{Path: "file-1", OID: originalFile},
-						ChangeFileMode{Path: "file-1", ExecutableMode: true},
+					actions: []git2go.Action{
+						git2go.CreateFile{Path: "file-1", OID: originalFile},
+						git2go.ChangeFileMode{Path: "file-1", ExecutableMode: true},
 					},
 					treeEntries: []testhelper.TreeEntry{
 						{Mode: ExecutableMode, Path: "file-1", Content: "original"},
@@ -371,16 +363,16 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "mark existing file executable",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateFile{Path: "file-1", OID: originalFile},
+					actions: []git2go.Action{
+						git2go.CreateFile{Path: "file-1", OID: originalFile},
 					},
 					treeEntries: []testhelper.TreeEntry{
 						{Mode: DefaultMode, Path: "file-1", Content: "original"},
 					},
 				},
 				{
-					actions: []Action{
-						ChangeFileMode{Path: "file-1", ExecutableMode: true},
+					actions: []git2go.Action{
+						git2go.ChangeFileMode{Path: "file-1", ExecutableMode: true},
 					},
 					treeEntries: []testhelper.TreeEntry{
 						{Mode: ExecutableMode, Path: "file-1", Content: "original"},
@@ -392,10 +384,10 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "move non-existing file",
 			steps: []step{
 				{
-					actions: []Action{
-						MoveFile{Path: "non-existing", NewPath: "destination"},
+					actions: []git2go.Action{
+						git2go.MoveFile{Path: "non-existing", NewPath: "destination"},
 					},
-					error: FileNotFoundError("non-existing"),
+					error: git2go.FileNotFoundError("non-existing"),
 				},
 			},
 		},
@@ -403,12 +395,12 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "move doesn't overwrite a file",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateFile{Path: "file-1", OID: originalFile},
-						CreateFile{Path: "file-2", OID: updatedFile},
-						MoveFile{Path: "file-1", NewPath: "file-2"},
+					actions: []git2go.Action{
+						git2go.CreateFile{Path: "file-1", OID: originalFile},
+						git2go.CreateFile{Path: "file-2", OID: updatedFile},
+						git2go.MoveFile{Path: "file-1", NewPath: "file-2"},
 					},
-					error: FileExistsError("file-2"),
+					error: git2go.FileExistsError("file-2"),
 				},
 			},
 		},
@@ -416,10 +408,10 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "delete non-existing file",
 			steps: []step{
 				{
-					actions: []Action{
-						DeleteFile{Path: "non-existing"},
+					actions: []git2go.Action{
+						git2go.DeleteFile{Path: "non-existing"},
 					},
-					error: FileNotFoundError("non-existing"),
+					error: git2go.FileNotFoundError("non-existing"),
 				},
 			},
 		},
@@ -427,9 +419,9 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "delete created file",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateFile{Path: "file-1", OID: originalFile},
-						DeleteFile{Path: "file-1"},
+					actions: []git2go.Action{
+						git2go.CreateFile{Path: "file-1", OID: originalFile},
+						git2go.DeleteFile{Path: "file-1"},
 					},
 				},
 			},
@@ -438,27 +430,27 @@ func TestExecutor_Commit(t *testing.T) {
 			desc: "delete existing file",
 			steps: []step{
 				{
-					actions: []Action{
-						CreateFile{Path: "file-1", OID: originalFile},
+					actions: []git2go.Action{
+						git2go.CreateFile{Path: "file-1", OID: originalFile},
 					},
 					treeEntries: []testhelper.TreeEntry{
 						{Mode: DefaultMode, Path: "file-1", Content: "original"},
 					},
 				},
 				{
-					actions: []Action{
-						DeleteFile{Path: "file-1"},
+					actions: []git2go.Action{
+						git2go.DeleteFile{Path: "file-1"},
 					},
 				},
 			},
 		},
 	} {
 		t.Run(tc.desc, func(t *testing.T) {
-			author := NewSignature("Author Name", "author.email@example.com", time.Now())
+			author := git2go.NewSignature("Author Name", "author.email@example.com", time.Now())
 			var parentCommit string
 			for i, step := range tc.steps {
 				message := fmt.Sprintf("commit %d", i+1)
-				commitID, err := executor.Commit(ctx, CommitParams{
+				commitID, err := executor.Commit(ctx, git2go.CommitParams{
 					Repository: repoPath,
 					Author:     author,
 					Message:    message,
@@ -522,7 +514,7 @@ func getCommit(t testing.TB, ctx context.Context, repo git.Repository, oid strin
 	return commit
 }
 
-func unmarshalSignature(t testing.TB, data string) Signature {
+func unmarshalSignature(t testing.TB, data string) git2go.Signature {
 	t.Helper()
 
 	// Format: NAME <EMAIL> DATE_UNIX DATE_TIMEZONE
@@ -538,7 +530,7 @@ func unmarshalSignature(t testing.TB, data string) Signature {
 	timestamp, err := strconv.ParseInt(split3[0], 10, 64)
 	require.NoError(t, err)
 
-	return Signature{
+	return git2go.Signature{
 		Name:  split1[0],
 		Email: split2[0],
 		When:  time.Unix(timestamp, 0),
diff --git a/internal/git2go/executor.go b/internal/git2go/executor.go
index 0007ab7e5..f6578cbc8 100644
--- a/internal/git2go/executor.go
+++ b/internal/git2go/executor.go
@@ -1,11 +1,29 @@
 package git2go
 
+import (
+	"bytes"
+	"context"
+	"io"
+)
+
+// RunFunc runns a command. Used for testing.
+type RunFunc func(context.Context, string, io.Reader, ...string) (*bytes.Buffer, error)
+
 // Executor executes gitaly-git2go.
 type Executor struct {
 	binaryPath string
+	run        RunFunc
 }
 
 // New returns a new gitaly-git2go executor using the provided binary.
 func New(binaryPath string) Executor {
-	return Executor{binaryPath: binaryPath}
+	return Executor{
+		binaryPath: binaryPath,
+		run:        run,
+	}
+}
+
+// NewWithRunner returns an Executor using the given run method. Used for testing.
+func NewWithRunner(run RunFunc) Executor {
+	return Executor{run: run}
 }
diff --git a/internal/git2go/executor_in_process_test.go b/internal/git2go/executor_in_process_test.go
new file mode 100644
index 000000000..73b0258f9
--- /dev/null
+++ b/internal/git2go/executor_in_process_test.go
@@ -0,0 +1,42 @@
+// +build static,system_libgit2
+
+package git2go_test
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+
+	"gitlab.com/gitlab-org/gitaly/cmd/gitaly-git2go/command"
+	"gitlab.com/gitlab-org/gitaly/internal/git2go"
+)
+
+func init() {
+	// When the test binary is compiled with libgit2, we'll run
+	// the tests additionally by making direct calls to gitaly-git2go
+	// without using a subprocess. This makes it possible to gather
+	// test coverage for the code in the subprocess as well.
+	bridge := git2go.NewWithRunner(func(ctx context.Context, binaryPath string, stdin io.Reader, args ...string) (*bytes.Buffer, error) {
+		if stdin == nil {
+			stdin = bytes.NewReader(nil)
+		}
+
+		stderr := &bytes.Buffer{}
+		stdout := &bytes.Buffer{}
+		errcode := command.Main(command.Process{
+			Args:   append([]string{"in-process"}, args...),
+			Stdin:  stdin,
+			Stdout: stdout,
+			Stderr: stderr,
+		})
+
+		if errcode != 0 {
+			return nil, fmt.Errorf("code: %d, stderr: %q", errcode, stderr)
+		}
+
+		return stdout, nil
+	})
+
+	executors["in-process"] = bridge
+}
diff --git a/internal/git2go/executor_test.go b/internal/git2go/executor_test.go
new file mode 100644
index 000000000..c345f7c36
--- /dev/null
+++ b/internal/git2go/executor_test.go
@@ -0,0 +1,29 @@
+package git2go_test
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"gitlab.com/gitlab-org/gitaly/internal/git2go"
+	"gitlab.com/gitlab-org/gitaly/internal/gitaly/config"
+	"gitlab.com/gitlab-org/gitaly/internal/testhelper"
+)
+
+var executors = map[string]git2go.Executor{}
+
+func TestMain(m *testing.M) {
+	testhelper.Configure()
+	testhelper.ConfigureGitalyGit2Go()
+
+	executors["subprocess"] = git2go.New(filepath.Join(config.Config.BinDir, "gitaly-git2go"))
+
+	os.Exit(m.Run())
+}
+
+// testExecutor is a helper for running a test with a subprocess and in-process.
+func testExecutors(t *testing.T, test func(*testing.T, git2go.Executor)) {
+	for name, executor := range executors {
+		t.Run(name, func(t *testing.T) { test(t, executor) })
+	}
+}