Add -m option to merge subcommand to allow user to set commit message

Signed-off-by: Jacob Stopak <jacob@initialcommit.io>

Author: initialcommit-io

README.md

@@ -204,7 +204,7 @@ Usage: `git-sim restore <file 1> <file 2> ... <file n>`
 Usage: `git-sim commit -m "Commit message"`
 
 - Simulated output will show the new commit added to the tip of the active branch
-- Specify your commit message after the -m option
+- Specify a commit message with the `-m` option
 - HEAD and the active branch will be moved to the new commit
 - Simulated output will show files in the staging area being included in the new commit
 - Supports amending the last commit with: `$ git-sim commit --amend -m "Amended commit message"`
@@ -256,12 +256,14 @@ Usage: `git-sim revert <to-revert>`
 ![git-sim-revert_01-05-23_22-16-59](https://user-images.githubusercontent.com/49353917/210941979-6db8b55c-2881-41d8-9e2e-6263b1dece13.jpg)
 
 ### git merge
-Usage: `git-sim merge <branch>`
+Usage: `git-sim merge <branch> [-m "Commit message"] [--no-ff]`
 
 - Specify `<branch>` as the branch name to merge into the active branch
+- If desired, specify a commit message with the `-m` option
 - Simulated output will depict a fast-forward merge if possible
 - Otherwise, a three-way merge will be depicted
 - To force a merge commit when a fast-forward is possible, use `--no-ff`
+- If merge fails due to merge conflicts, the conflicting files are displayed
 
 ![git-sim-merge_01-05-23_09-44-46](https://user-images.githubusercontent.com/49353917/210942030-c7229488-571a-4943-a1f4-c6e4a0c8ccf3.jpg)
 

git_sim/commands.py

@@ -153,10 +153,16 @@ def merge(
         "--no-ff",
         help="Simulate creation of a merge commit in all cases, even when the merge could instead be resolved as a fast-forward",
     ),
+    message: str = typer.Option(
+        "Merge commit",
+        "--message",
+        "-m",
+        help="The commit message of the new merge commit",
+    ),
 ):
     from git_sim.merge import Merge
 
-    scene = Merge(branch=branch, no_ff=no_ff)
+    scene = Merge(branch=branch, no_ff=no_ff, message=message)
     handle_animations(scene=scene)
 
 

git_sim/merge.py

@@ -13,10 +13,11 @@
 
 
 class Merge(GitSimBaseCommand):
-    def __init__(self, branch: str, no_ff: bool):
+    def __init__(self, branch: str, no_ff: bool, message: str):
         super().__init__()
         self.branch = branch
         self.no_ff = no_ff
+        self.message = message
 
         try:
             git.repo.fun.rev_parse(self.repo, self.branch)
@@ -76,7 +77,7 @@ def construct(self):
 
             if self.no_ff:
                 self.center_frame_on_commit(branch_commit)
-                commitId = self.setup_and_draw_parent(branch_commit, "Merge commit")
+                commitId = self.setup_and_draw_parent(branch_commit, self.message)
 
                 # If pre-merge HEAD is on screen, drawn an arrow to it as 2nd parent
                 if head_commit.hexsha in self.drawnCommits:
@@ -129,7 +130,7 @@ def construct(self):
                 self.center_frame_on_commit(head_commit)
                 self.setup_and_draw_parent(
                     head_commit,
-                    "Merge commit",
+                    self.message,
                     shift=2 * m.DOWN,
                     draw_arrow=False,
                     color=m.GRAY,