Construct arg vector manually rather than parse string

By constructing an arg vector manually, we no longer need to quote arguments

Mandate that args must be passed when building a command

Now you need to provide an args array when building a command.
There are a handful of places where we need to deal with a string,
such as with user-defined custom commands, and for those we now require
that at the callsite they use str.ToArgv to do that. I don't want
to provide a method out of the box for it because I want to discourage its
use.

For some reason we were invoking a command through a shell when amending a
commit, and I don't believe we needed to do that as there was nothing user-
supplied about the command. So I've switched to using a regular command out-
side the shell there

pkg/integration/tests/patch_building/apply.go

@@ -7,7 +7,7 @@ import (
 
 var Apply = NewIntegrationTest(NewIntegrationTestArgs{
 	Description:  "Apply a custom patch",
-	ExtraCmdArgs: "",
+	ExtraCmdArgs: []string{},
 	Skip:         false,
 	SetupConfig:  func(config *config.AppConfig) {},
 	SetupRepo: func(shell *Shell) {

pkg/integration/tests/patch_building/apply_in_reverse.go

@@ -7,7 +7,7 @@ import (
 
 var ApplyInReverse = NewIntegrationTest(NewIntegrationTestArgs{
 	Description:  "Apply a custom patch in reverse",
-	ExtraCmdArgs: "",
+	ExtraCmdArgs: []string{},
 	Skip:         false,
 	SetupConfig:  func(config *config.AppConfig) {},
 	SetupRepo: func(shell *Shell) {

pkg/integration/tests/patch_building/apply_in_reverse_with_conflict.go

@@ -7,7 +7,7 @@ import (
 
 var ApplyInReverseWithConflict = NewIntegrationTest(NewIntegrationTestArgs{
 	Description:  "Apply a custom patch in reverse, resulting in a conflict",
-	ExtraCmdArgs: "",
+	ExtraCmdArgs: []string{},
 	Skip:         false,
 	SetupConfig:  func(config *config.AppConfig) {},
 	SetupRepo: func(shell *Shell) {

pkg/integration/tests/patch_building/copy_patch_to_clipboard.go

@@ -7,7 +7,7 @@ import (
 
 var CopyPatchToClipboard = NewIntegrationTest(NewIntegrationTestArgs{
 	Description:  "Create a patch from the commits and copy the patch to clipbaord.",
-	ExtraCmdArgs: "",
+	ExtraCmdArgs: []string{},
 	Skip:         true, // skipping because CI doesn't have clipboard functionality
 	SetupConfig:  func(config *config.AppConfig) {},
 	SetupRepo: func(shell *Shell) {

pkg/integration/tests/patch_building/move_to_earlier_commit.go

@@ -7,7 +7,7 @@ import (
 
 var MoveToEarlierCommit = NewIntegrationTest(NewIntegrationTestArgs{
 	Description:  "Move a patch from a commit to an earlier commit",
-	ExtraCmdArgs: "",
+	ExtraCmdArgs: []string{},
 	Skip:         false,
 	GitVersion:   AtLeast("2.26.0"),
 	SetupConfig:  func(config *config.AppConfig) {},

pkg/integration/tests/patch_building/move_to_earlier_commit_no_keep_empty.go

@@ -7,7 +7,7 @@ import (
 
 var MoveToEarlierCommitNoKeepEmpty = NewIntegrationTest(NewIntegrationTestArgs{
 	Description:  "Move a patch from a commit to an earlier commit, for older git versions that don't keep the empty commit",
-	ExtraCmdArgs: "",
+	ExtraCmdArgs: []string{},
 	Skip:         false,
 	GitVersion:   Before("2.26.0"),
 	SetupConfig:  func(config *config.AppConfig) {},

pkg/integration/tests/patch_building/move_to_index.go

@@ -7,7 +7,7 @@ import (
 
 var MoveToIndex = NewIntegrationTest(NewIntegrationTestArgs{
 	Description:  "Move a patch from a commit to the index",
-	ExtraCmdArgs: "",
+	ExtraCmdArgs: []string{},
 	Skip:         false,
 	SetupConfig:  func(config *config.AppConfig) {},
 	SetupRepo: func(shell *Shell) {

pkg/integration/tests/patch_building/move_to_index_part_of_adjacent_added_lines.go

@@ -7,7 +7,7 @@ import (
 
 var MoveToIndexPartOfAdjacentAddedLines = NewIntegrationTest(NewIntegrationTestArgs{
 	Description:  "Move a patch from a commit to the index, with only some lines of a range of adjacent added lines in the patch",
-	ExtraCmdArgs: "",
+	ExtraCmdArgs: []string{},
 	Skip:         false,
 	SetupConfig:  func(config *config.AppConfig) {},
 	SetupRepo: func(shell *Shell) {

pkg/integration/tests/patch_building/move_to_index_partial.go

@@ -7,7 +7,7 @@ import (
 
 var MoveToIndexPartial = NewIntegrationTest(NewIntegrationTestArgs{
 	Description:  "Move a patch from a commit to the index. This is different from the MoveToIndex test in that we're only selecting a partial patch from a file",
-	ExtraCmdArgs: "",
+	ExtraCmdArgs: []string{},
 	Skip:         false,
 	SetupConfig:  func(config *config.AppConfig) {},
 	SetupRepo: func(shell *Shell) {

pkg/integration/tests/patch_building/move_to_index_with_conflict.go

@@ -7,7 +7,7 @@ import (
 
 var MoveToIndexWithConflict = NewIntegrationTest(NewIntegrationTestArgs{
 	Description:  "Move a patch from a commit to the index, causing a conflict",
-	ExtraCmdArgs: "",
+	ExtraCmdArgs: []string{},
 	Skip:         false,
 	SetupConfig:  func(config *config.AppConfig) {},
 	SetupRepo: func(shell *Shell) {

pkg/integration/tests/patch_building/move_to_later_commit.go

@@ -7,7 +7,7 @@ import (
 
 var MoveToLaterCommit = NewIntegrationTest(NewIntegrationTestArgs{
 	Description:  "Move a patch from a commit to a later commit",
-	ExtraCmdArgs: "",
+	ExtraCmdArgs: []string{},
 	Skip:         false,
 	SetupConfig:  func(config *config.AppConfig) {},
 	SetupRepo: func(shell *Shell) {

pkg/integration/tests/patch_building/move_to_later_commit_partial_hunk.go

@@ -7,7 +7,7 @@ import (
 
 var MoveToLaterCommitPartialHunk = NewIntegrationTest(NewIntegrationTestArgs{
 	Description:  "Move a patch from a commit to a later commit, with only parts of a hunk in the patch",
-	ExtraCmdArgs: "",
+	ExtraCmdArgs: []string{},
 	Skip:         false,
 	SetupConfig:  func(config *config.AppConfig) {},
 	SetupRepo: func(shell *Shell) {

pkg/integration/tests/patch_building/move_to_new_commit.go

@@ -7,7 +7,7 @@ import (
 
 var MoveToNewCommit = NewIntegrationTest(NewIntegrationTestArgs{
 	Description:  "Move a patch from a commit to a new commit",
-	ExtraCmdArgs: "",
+	ExtraCmdArgs: []string{},
 	Skip:         false,
 	SetupConfig:  func(config *config.AppConfig) {},
 	SetupRepo: func(shell *Shell) {

pkg/integration/tests/patch_building/move_to_new_commit_partial_hunk.go

@@ -7,7 +7,7 @@ import (
 
 var MoveToNewCommitPartialHunk = NewIntegrationTest(NewIntegrationTestArgs{
 	Description:  "Move a patch from a commit to a new commit, with only parts of a hunk in the patch",
-	ExtraCmdArgs: "",
+	ExtraCmdArgs: []string{},
 	Skip:         false,
 	SetupConfig:  func(config *config.AppConfig) {},
 	SetupRepo: func(shell *Shell) {

pkg/integration/tests/patch_building/remove_from_commit.go

@@ -7,7 +7,7 @@ import (
 
 var RemoveFromCommit = NewIntegrationTest(NewIntegrationTestArgs{
 	Description:  "Remove a custom patch from a commit",
-	ExtraCmdArgs: "",
+	ExtraCmdArgs: []string{},
 	Skip:         false,
 	SetupConfig:  func(config *config.AppConfig) {},
 	SetupRepo: func(shell *Shell) {

pkg/integration/tests/patch_building/reset_with_escape.go

@@ -7,7 +7,7 @@ import (
 
 var ResetWithEscape = NewIntegrationTest(NewIntegrationTestArgs{
 	Description:  "Reset a custom patch with the escape keybinding",
-	ExtraCmdArgs: "",
+	ExtraCmdArgs: []string{},
 	Skip:         false,
 	SetupConfig:  func(config *config.AppConfig) {},
 	SetupRepo: func(shell *Shell) {

pkg/integration/tests/patch_building/select_all_files.go

@@ -7,7 +7,7 @@ import (
 
 var SelectAllFiles = NewIntegrationTest(NewIntegrationTestArgs{
 	Description:  "All all files of a commit to a custom patch with the 'a' keybinding",
-	ExtraCmdArgs: "",
+	ExtraCmdArgs: []string{},
 	Skip:         false,
 	SetupConfig:  func(config *config.AppConfig) {},
 	SetupRepo: func(shell *Shell) {

pkg/integration/tests/patch_building/specific_selection.go

@@ -7,7 +7,7 @@ import (
 
 var SpecificSelection = NewIntegrationTest(NewIntegrationTestArgs{
 	Description:  "Build a custom patch with a specific selection of lines, adding individual lines, as well as a range and hunk, and adding a file directly",
-	ExtraCmdArgs: "",
+	ExtraCmdArgs: []string{},
 	Skip:         false,
 	SetupConfig:  func(config *config.AppConfig) {},
 	SetupRepo: func(shell *Shell) {

pkg/integration/tests/patch_building/start_new_patch.go

@@ -7,7 +7,7 @@ import (
 
 var StartNewPatch = NewIntegrationTest(NewIntegrationTestArgs{
 	Description:  "Attempt to add a file from another commit to a patch, then agree to start a new patch",
-	ExtraCmdArgs: "",
+	ExtraCmdArgs: []string{},
 	Skip:         false,
 	SetupConfig:  func(config *config.AppConfig) {},
 	SetupRepo: func(shell *Shell) {