diff --git a/main.go b/main.go
index 890b69a7f..edf1e7207 100644
--- a/main.go
+++ b/main.go
@@ -3,6 +3,7 @@ package main
 import (
 	"flag"
 	"fmt"
+	"log"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -40,13 +41,13 @@ func main() {
 	}
 	appConfig, err := config.NewAppConfig("lazygit", version, commit, date, buildSource, debuggingFlag)
 	if err != nil {
-		panic(err)
+		log.Fatal(err.Error())
 	}
 
 	app, err := app.Setup(appConfig)
 	if err != nil {
 		app.Log.Error(err.Error())
-		panic(err)
+		log.Fatal(err.Error())
 	}
 
 	app.Gui.RunWithSubprocesses()
diff --git a/pkg/commands/git.go b/pkg/commands/git.go
index 3fb46fff7..017bd815f 100644
--- a/pkg/commands/git.go
+++ b/pkg/commands/git.go
@@ -327,56 +327,50 @@ func (c *GitCommand) Push(branchName string, force bool) error {
 // retaining the message of the higher commit
 func (c *GitCommand) SquashPreviousTwoCommits(message string) error {
 	// TODO: test this
-	err := c.OSCommand.RunCommand("git reset --soft HEAD^")
-	if err != nil {
+	if err := c.OSCommand.RunCommand("git reset --soft HEAD^"); err != nil {
 		return err
 	}
 	// TODO: if password is required, we need to return a subprocess
-	return c.OSCommand.RunCommand("git commit --amend -m " + c.OSCommand.Quote(message))
+	return c.OSCommand.RunCommand(fmt.Sprintf("git commit --amend -m %s", c.OSCommand.Quote(message)))
 }
 
 // SquashFixupCommit squashes a 'FIXUP' commit into the commit beneath it,
 // retaining the commit message of the lower commit
 func (c *GitCommand) SquashFixupCommit(branchName string, shaValue string) error {
-	var err error
 	commands := []string{
-		"git checkout -q " + shaValue,
-		"git reset --soft " + shaValue + "^",
-		"git commit --amend -C " + shaValue + "^",
-		"git rebase --onto HEAD " + shaValue + " " + branchName,
+		fmt.Sprintf("git checkout -q %s", shaValue),
+		fmt.Sprintf("git reset --soft %s^", shaValue),
+		fmt.Sprintf("git commit --amend -C %s^", shaValue),
+		fmt.Sprintf("git rebase --onto HEAD %s %s", shaValue, branchName),
 	}
-	ret := ""
 	for _, command := range commands {
 		c.Log.Info(command)
-		output, err := c.OSCommand.RunCommandWithOutput(command)
-		ret += output
-		if err != nil {
+
+		if output, err := c.OSCommand.RunCommandWithOutput(command); err != nil {
+			ret := output
+			// We are already in an error state here so we're just going to append
+			// the output of these commands
+			output, _ := c.OSCommand.RunCommandWithOutput(fmt.Sprintf("git branch -d %s", shaValue))
+			ret += output
+			output, _ = c.OSCommand.RunCommandWithOutput(fmt.Sprintf("git checkout %s", branchName))
+			ret += output
+
 			c.Log.Info(ret)
-			break
+			return errors.New(ret)
 		}
 	}
-	if err != nil {
-		// We are already in an error state here so we're just going to append
-		// the output of these commands
-		output, _ := c.OSCommand.RunCommandWithOutput("git branch -d " + shaValue)
-		ret += output
-		output, _ = c.OSCommand.RunCommandWithOutput("git checkout " + branchName)
-		ret += output
-	}
-	if err != nil {
-		return errors.New(ret)
-	}
+
 	return nil
 }
 
-// CatFile obtain the contents of a file
+// CatFile obtains the content of a file
 func (c *GitCommand) CatFile(fileName string) (string, error) {
-	return c.OSCommand.RunCommandWithOutput("cat " + c.OSCommand.Quote(fileName))
+	return c.OSCommand.RunCommandWithOutput(fmt.Sprintf("cat %s", c.OSCommand.Quote(fileName)))
 }
 
 // StageFile stages a file
 func (c *GitCommand) StageFile(fileName string) error {
-	return c.OSCommand.RunCommand("git add " + c.OSCommand.Quote(fileName))
+	return c.OSCommand.RunCommand(fmt.Sprintf("git add %s", c.OSCommand.Quote(fileName)))
 }
 
 // StageAll stages all files
@@ -391,13 +385,11 @@ func (c *GitCommand) UnstageAll() error {
 
 // UnStageFile unstages a file
 func (c *GitCommand) UnStageFile(fileName string, tracked bool) error {
-	var command string
+	command := "git rm --cached %s"
 	if tracked {
-		command = "git reset HEAD "
-	} else {
-		command = "git rm --cached "
+		command = "git reset HEAD %s"
 	}
-	return c.OSCommand.RunCommand(command + c.OSCommand.Quote(fileName))
+	return c.OSCommand.RunCommand(fmt.Sprintf(command, c.OSCommand.Quote(fileName)))
 }
 
 // GitStatus returns the plaintext short status of the repo
diff --git a/pkg/commands/git_test.go b/pkg/commands/git_test.go
index bda3ea225..88ecaea66 100644
--- a/pkg/commands/git_test.go
+++ b/pkg/commands/git_test.go
@@ -917,7 +917,7 @@ func TestGitCommandPush(t *testing.T) {
 			},
 		},
 		{
-			"Push with force enable",
+			"Push with force enabled",
 			func(cmd string, args ...string) *exec.Cmd {
 				assert.EqualValues(t, "git", cmd)
 				assert.EqualValues(t, []string{"push", "--force-with-lease", "-u", "origin", "test"}, args)
@@ -953,6 +953,272 @@ func TestGitCommandPush(t *testing.T) {
 	}
 }
 
+func TestGitCommandSquashPreviousTwoCommits(t *testing.T) {
+	type scenario struct {
+		testName string
+		command  func(string, ...string) *exec.Cmd
+		test     func(error)
+	}
+
+	scenarios := []scenario{
+		{
+			"Git reset triggers an error",
+			func(cmd string, args ...string) *exec.Cmd {
+				assert.EqualValues(t, "git", cmd)
+				assert.EqualValues(t, []string{"reset", "--soft", "HEAD^"}, args)
+
+				return exec.Command("exit", "1")
+			},
+			func(err error) {
+				assert.NotNil(t, err)
+			},
+		},
+		{
+			"Git commit triggers an error",
+			func(cmd string, args ...string) *exec.Cmd {
+				if len(args) > 0 && args[0] == "reset" {
+					return exec.Command("echo")
+				}
+
+				assert.EqualValues(t, "git", cmd)
+				assert.EqualValues(t, []string{"commit", "--amend", "-m", "test"}, args)
+
+				return exec.Command("exit", "1")
+			},
+			func(err error) {
+				assert.NotNil(t, err)
+			},
+		},
+		{
+			"Stash succeeded",
+			func(cmd string, args ...string) *exec.Cmd {
+				if len(args) > 0 && args[0] == "reset" {
+					return exec.Command("echo")
+				}
+
+				assert.EqualValues(t, "git", cmd)
+				assert.EqualValues(t, []string{"commit", "--amend", "-m", "test"}, args)
+
+				return exec.Command("echo")
+			},
+			func(err error) {
+				assert.Nil(t, err)
+			},
+		},
+	}
+
+	for _, s := range scenarios {
+		t.Run(s.testName, func(t *testing.T) {
+			gitCmd := newDummyGitCommand()
+			gitCmd.OSCommand.command = s.command
+			s.test(gitCmd.SquashPreviousTwoCommits("test"))
+		})
+	}
+}
+
+func TestGitCommandSquashFixupCommit(t *testing.T) {
+	type scenario struct {
+		testName string
+		command  func() (func(string, ...string) *exec.Cmd, *[][]string)
+		test     func(*[][]string, error)
+	}
+
+	scenarios := []scenario{
+		{
+			"An error occurred with one of the sub git command",
+			func() (func(string, ...string) *exec.Cmd, *[][]string) {
+				cmdsCalled := [][]string{}
+				return func(cmd string, args ...string) *exec.Cmd {
+					cmdsCalled = append(cmdsCalled, args)
+					if len(args) > 0 && args[0] == "checkout" {
+						return exec.Command("exit", "1")
+					}
+
+					return exec.Command("echo")
+				}, &cmdsCalled
+			},
+			func(cmdsCalled *[][]string, err error) {
+				assert.NotNil(t, err)
+				assert.Len(t, *cmdsCalled, 3)
+				assert.EqualValues(t, *cmdsCalled, [][]string{
+					{"checkout", "-q", "6789abcd"},
+					{"branch", "-d", "6789abcd"},
+					{"checkout", "test"},
+				})
+			},
+		},
+		{
+			"Squash fixup succeeded",
+			func() (func(string, ...string) *exec.Cmd, *[][]string) {
+				cmdsCalled := [][]string{}
+				return func(cmd string, args ...string) *exec.Cmd {
+					cmdsCalled = append(cmdsCalled, args)
+					return exec.Command("echo")
+				}, &cmdsCalled
+			},
+			func(cmdsCalled *[][]string, err error) {
+				assert.Nil(t, err)
+				assert.Len(t, *cmdsCalled, 4)
+				assert.EqualValues(t, *cmdsCalled, [][]string{
+					{"checkout", "-q", "6789abcd"},
+					{"reset", "--soft", "6789abcd^"},
+					{"commit", "--amend", "-C", "6789abcd^"},
+					{"rebase", "--onto", "HEAD", "6789abcd", "test"},
+				})
+			},
+		},
+	}
+
+	for _, s := range scenarios {
+		t.Run(s.testName, func(t *testing.T) {
+			var cmdsCalled *[][]string
+			gitCmd := newDummyGitCommand()
+			gitCmd.OSCommand.command, cmdsCalled = s.command()
+			s.test(cmdsCalled, gitCmd.SquashFixupCommit("test", "6789abcd"))
+		})
+	}
+}
+
+func TestGitCommandCatFile(t *testing.T) {
+	gitCmd := newDummyGitCommand()
+	gitCmd.OSCommand.command = func(cmd string, args ...string) *exec.Cmd {
+		assert.EqualValues(t, "cat", cmd)
+		assert.EqualValues(t, []string{"test.txt"}, args)
+
+		return exec.Command("echo", "-n", "test")
+	}
+
+	o, err := gitCmd.CatFile("test.txt")
+	assert.NoError(t, err)
+	assert.Equal(t, "test", o)
+}
+
+func TestGitCommandStageFile(t *testing.T) {
+	gitCmd := newDummyGitCommand()
+	gitCmd.OSCommand.command = func(cmd string, args ...string) *exec.Cmd {
+		assert.EqualValues(t, "git", cmd)
+		assert.EqualValues(t, []string{"add", "test.txt"}, args)
+
+		return exec.Command("echo")
+	}
+
+	assert.NoError(t, gitCmd.StageFile("test.txt"))
+}
+
+func TestGitCommandUnstageFile(t *testing.T) {
+	type scenario struct {
+		testName string
+		command  func(string, ...string) *exec.Cmd
+		test     func(error)
+		tracked  bool
+	}
+
+	scenarios := []scenario{
+		{
+			"Remove an untracked file from staging",
+			func(cmd string, args ...string) *exec.Cmd {
+				assert.EqualValues(t, "git", cmd)
+				assert.EqualValues(t, []string{"rm", "--cached", "test.txt"}, args)
+
+				return exec.Command("echo")
+			},
+			func(err error) {
+				assert.NoError(t, err)
+			},
+			false,
+		},
+		{
+			"Remove a tracked file from staging",
+			func(cmd string, args ...string) *exec.Cmd {
+				assert.EqualValues(t, "git", cmd)
+				assert.EqualValues(t, []string{"reset", "HEAD", "test.txt"}, args)
+
+				return exec.Command("echo")
+			},
+			func(err error) {
+				assert.NoError(t, err)
+			},
+			true,
+		},
+	}
+
+	for _, s := range scenarios {
+		t.Run(s.testName, func(t *testing.T) {
+			gitCmd := newDummyGitCommand()
+			gitCmd.OSCommand.command = s.command
+			s.test(gitCmd.UnStageFile("test.txt", s.tracked))
+		})
+	}
+}
+
+func TestGitCommandIsInMergeState(t *testing.T) {
+	type scenario struct {
+		testName string
+		command  func(string, ...string) *exec.Cmd
+		test     func(bool, error)
+	}
+
+	scenarios := []scenario{
+		{
+			"An error occurred when running status command",
+			func(cmd string, args ...string) *exec.Cmd {
+				assert.EqualValues(t, "git", cmd)
+				assert.EqualValues(t, []string{"status", "--untracked-files=all"}, args)
+
+				return exec.Command("exit", "1")
+			},
+			func(isInMergeState bool, err error) {
+				assert.Error(t, err)
+				assert.False(t, isInMergeState)
+			},
+		},
+		{
+			"Is not in merge state",
+			func(cmd string, args ...string) *exec.Cmd {
+				assert.EqualValues(t, "git", cmd)
+				assert.EqualValues(t, []string{"status", "--untracked-files=all"}, args)
+				return exec.Command("echo")
+			},
+			func(isInMergeState bool, err error) {
+				assert.False(t, isInMergeState)
+				assert.NoError(t, err)
+			},
+		},
+		{
+			"Command output contains conclude merge",
+			func(cmd string, args ...string) *exec.Cmd {
+				assert.EqualValues(t, "git", cmd)
+				assert.EqualValues(t, []string{"status", "--untracked-files=all"}, args)
+				return exec.Command("echo", "'conclude merge'")
+			},
+			func(isInMergeState bool, err error) {
+				assert.True(t, isInMergeState)
+				assert.NoError(t, err)
+			},
+		},
+		{
+			"Command output contains unmerged paths",
+			func(cmd string, args ...string) *exec.Cmd {
+				assert.EqualValues(t, "git", cmd)
+				assert.EqualValues(t, []string{"status", "--untracked-files=all"}, args)
+				return exec.Command("echo", "'unmerged paths'")
+			},
+			func(isInMergeState bool, err error) {
+				assert.True(t, isInMergeState)
+				assert.NoError(t, err)
+			},
+		},
+	}
+
+	for _, s := range scenarios {
+		t.Run(s.testName, func(t *testing.T) {
+			gitCmd := newDummyGitCommand()
+			gitCmd.OSCommand.command = s.command
+			s.test(gitCmd.IsInMergeState())
+		})
+	}
+}
+
 func TestGitCommandDiff(t *testing.T) {
 	gitCommand := newDummyGitCommand()
 	assert.NoError(t, test.GenerateRepo("lots_of_diffs.sh"))