Save and restore WIP state while executing clear-local

As `clear-local` manipulates with branches, all uncommitted changes have
to be stashed prior to its execution. Also, the stash has to be applied
back to the correct branch. That's why the branch, which was a current one
before the command execution, has to be checkout.

docs/commands.md

@@ -142,6 +142,10 @@ removes them by invoking `git branch -d`. If there are unmerged branches, you
 have to choose either batch or one-by-one deletion procedure using
 `git branch -D`.
 
+Prior to the execution, a current state is saved (a branch with modifications).
+After the successful accepting a work, the state will be restored. In the case
+of a failure, you need to go to the desired branch and apply a stash if needed.
+
 Approximate commands flow is
 ```bash
 ==>> git elegant clear-local

libexec/git-elegant-clear-local

@@ -20,6 +20,10 @@ removes them by invoking \`git branch -d\`. If there are unmerged branches, you
 have to choose either batch or one-by-one deletion procedure using
 \`git branch -D\`.
 
+Prior to the execution, a current state is saved (a branch with modifications).
+After the successful accepting a work, the state will be restored. In the case
+of a failure, you need to go to the desired branch and apply a stash if needed.
+
 Approximate commands flow is
 \`\`\`bash
 ==>> git elegant clear-local
@@ -30,7 +34,7 @@ git branch -D task-1
 MESSAGE
 }
 
-default() {
+--clear-local-logic() {
     git-verbose checkout ${MASTER}
     local cmd="git branch -lvv | grep gone | awk {'print \$1'}"
     __loop "git-verbose branch -d" $(eval "$cmd") || \
@@ -40,3 +44,7 @@ default() {
             __batch "Do you want to delete all unmerged branches?" "Delete this?" "git-verbose branch -D" $(eval "$cmd")
         )
 }
+
+default() {
+    stash-pipe branch-pipe --clear-local-logic
+}

tests/git-elegant-clear-local.bats

@@ -20,3 +20,13 @@ teardown() {
     check git-elegant clear-local
     [[ "${status}" -eq 0 ]]
 }
+
+@test "'clear-local': save WIP prior cleaning and restore after it" {
+    gitrepo "git checkout -b other"
+    gitrepo "echo stash >> ${FILE_TO_MODIFY}"
+    check git-elegant clear-local
+    [[ "${status}" -eq 0 ]]
+    [[ "${lines[@]}" =~ "git stash push" ]]
+    [[ "${lines[@]}" =~ "git stash pop" ]]
+    [[ "${lines[@]}" =~ "git checkout other" ]]
+}