refactor: test utils and simplify the case code

tests/README.md

@@ -12,7 +12,7 @@ The test part depends on:
 
 So the versions are higher than above is recommended.
 
-# How to test
+# How to run the tests
 1. Install `poetry`
 2. Install the dependencies via `poetry install --no-root`
 3. Run `poetry run pytest`
@@ -26,6 +26,18 @@ It is done or go without `poetry`,
 
 The second way maybe blocked the some missing dependencies at someday, so the first one is recommended.
 
+# What and how to create a unit test
+One command has a unit test, because one `git-*` command is just do one thing, so we can eat a piece of `git-*` command in one time.
+
+For example,
+
+1. The `git-alias` should has a test suite, so create `test_git_alias.py` in the directory `test`
+2. Create a test class `TestGitAlias` in the `test_git_alias.py`
+3. Create a test case `test_init`, and some test fixtures can be used, `temp_repo`, `named_temp_repo` etc.
+    * `temp_repo` is module scoped fixture which create a temporary directory and available in the test suite `test_git_alias.py`.
+    * `named_temp_repo` is just same as `temp_repo` except the custom directory renaming.
+4. Loop the third step until the 100% coverage of the function of the `git-alias`
+
 # References
 * [poetry](https://github.com/python-poetry/poetry)
 * [pytest](https://github.com/pytest-dev/pytest/)

tests/helper.py

@@ -1,10 +1,15 @@
 import os, subprocess, shutil, tempfile
-from git import Repo
+from git import Repo, GitCommandError
+from testpath import MockCommand, modified_env
 
 CURRENT_DIR = os.path.dirname(os.path.abspath(__file__))
 GIT_EXTRAS_BIN = os.path.abspath(os.path.join(CURRENT_DIR, "..", "bin"))
 GIT_EXTRAS_HELPER = os.path.abspath(os.path.join(CURRENT_DIR, "..", "helper"))
 
+GITHUB_ORIGIN = "https://github.com/tj/git-extras.git"
+GITLAB_ORIGIN = "https://gitlab.com/tj/git-extras.git"
+BITBUCKET_ORIGIN = "https://bitbucket.org/tj/git-extras.git"
+
 class TempRepository:
     def __init__(self, repo_work_dir = None):
         self._system_tmpdir = tempfile.gettempdir()
@@ -16,6 +21,7 @@ def __init__(self, repo_work_dir = None):
         self._tempdirname = self._cwd[len(self._system_tmpdir) + 1:]
         self._git_repo = Repo.init(repo_work_dir, b="default")
         self._files = []
+        self.change_origin_to_github()
 
     def switch_cwd_under_repo(self):
         os.chdir(self._cwd)
@@ -33,6 +39,10 @@ def get_repo_git(self):
     def get_file(self, index):
         return self._files[index]
 
+    def get_filename(self, index):
+        file = self._files[index]
+        return file[1:]
+
     def get_files(self):
         return self._files
 
@@ -98,3 +108,19 @@ def invoke_installed_extras_command(self, name, *params):
         script = [temp_extras_command, *params]
         print(f"Run the script \"{script}\"")
         return subprocess.run(script, capture_output=True)
+
+    def change_origin(self, origin_url):
+        try:
+            self._git_repo.git.remote("add", "origin", origin_url)
+        except GitCommandError:
+            pass
+        self._git_repo.git.remote("set-url", "origin", origin_url)
+
+    def change_origin_to_github(self):
+        self.change_origin(GITHUB_ORIGIN)
+
+    def change_origin_to_gitlab(self):
+        self.change_origin(GITLAB_ORIGIN)
+
+    def change_origin_to_bitbucket(self):
+        self.change_origin(BITBUCKET_ORIGIN)