factor out code from git.go

pkg/commands/loading_commits_test.go

@@ -0,0 +1,112 @@
+package commands
+
+import (
+	"os/exec"
+	"testing"
+
+	"github.com/jesseduffield/lazygit/pkg/i18n"
+	"github.com/jesseduffield/lazygit/pkg/utils"
+	"github.com/stretchr/testify/assert"
+)
+
+// NewDummyCommitListBuilder creates a new dummy CommitListBuilder for testing
+func NewDummyCommitListBuilder() *CommitListBuilder {
+	osCommand := NewDummyOSCommand()
+
+	return &CommitListBuilder{
+		Log:        utils.NewDummyLog(),
+		GitCommand: NewDummyGitCommandWithOSCommand(osCommand),
+		OSCommand:  osCommand,
+		Tr:         i18n.NewLocalizer(utils.NewDummyLog()),
+	}
+}
+
+// TestCommitListBuilderGetMergeBase is a function.
+func TestCommitListBuilderGetMergeBase(t *testing.T) {
+	type scenario struct {
+		testName string
+		command  func(string, ...string) *exec.Cmd
+		test     func(string, error)
+	}
+
+	scenarios := []scenario{
+		{
+			"swallows an error if the call to merge-base returns an error",
+			func(cmd string, args ...string) *exec.Cmd {
+				assert.EqualValues(t, "git", cmd)
+
+				switch args[0] {
+				case "symbolic-ref":
+					assert.EqualValues(t, []string{"symbolic-ref", "--short", "HEAD"}, args)
+					return exec.Command("echo", "master")
+				case "merge-base":
+					assert.EqualValues(t, []string{"merge-base", "HEAD", "master"}, args)
+					return exec.Command("test")
+				}
+				return nil
+			},
+			func(output string, err error) {
+				assert.NoError(t, err)
+				assert.EqualValues(t, "", output)
+			},
+		},
+		{
+			"returns the commit when master",
+			func(cmd string, args ...string) *exec.Cmd {
+				assert.EqualValues(t, "git", cmd)
+
+				switch args[0] {
+				case "symbolic-ref":
+					assert.EqualValues(t, []string{"symbolic-ref", "--short", "HEAD"}, args)
+					return exec.Command("echo", "master")
+				case "merge-base":
+					assert.EqualValues(t, []string{"merge-base", "HEAD", "master"}, args)
+					return exec.Command("echo", "blah")
+				}
+				return nil
+			},
+			func(output string, err error) {
+				assert.NoError(t, err)
+				assert.Equal(t, "blah", output)
+			},
+		},
+		{
+			"checks against develop when a feature branch",
+			func(cmd string, args ...string) *exec.Cmd {
+				assert.EqualValues(t, "git", cmd)
+
+				switch args[0] {
+				case "symbolic-ref":
+					assert.EqualValues(t, []string{"symbolic-ref", "--short", "HEAD"}, args)
+					return exec.Command("echo", "feature/test")
+				case "merge-base":
+					assert.EqualValues(t, []string{"merge-base", "HEAD", "develop"}, args)
+					return exec.Command("echo", "blah")
+				}
+				return nil
+			},
+			func(output string, err error) {
+				assert.NoError(t, err)
+				assert.Equal(t, "blah", output)
+			},
+		},
+		{
+			"bubbles up error if there is one",
+			func(cmd string, args ...string) *exec.Cmd {
+				return exec.Command("test")
+			},
+			func(output string, err error) {
+				assert.Error(t, err)
+				assert.Equal(t, "", output)
+			},
+		},
+	}
+
+	for _, s := range scenarios {
+		t.Run(s.testName, func(t *testing.T) {
+			c := NewDummyCommitListBuilder()
+			c.OSCommand.SetCommand(s.command)
+			s.test(c.getMergeBase("HEAD"))
+		})
+	}
+}