tests: create new file for tests of commit template

An important part of the `jj log` output is the commit template. I
suspect we'll have many more tests for that, so let's move it to a
separate file. The main `test_log_command.rs` can focus on which
commits to display.

tests/test_commit_template.rs

@@ -0,0 +1,52 @@
+// Copyright 2023 The Jujutsu Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use common::TestEnvironment;
+use regex::Regex;
+
+pub mod common;
+
+#[test]
+fn test_log_author_timestamp() {
+    let test_env = TestEnvironment::default();
+    test_env.jj_cmd_success(test_env.env_root(), &["init", "repo", "--git"]);
+    let repo_path = test_env.env_root().join("repo");
+
+    test_env.jj_cmd_success(&repo_path, &["describe", "-m", "first"]);
+    test_env.jj_cmd_success(&repo_path, &["new", "-m", "second"]);
+
+    let stdout = test_env.jj_cmd_success(&repo_path, &["log", "-T", "author.timestamp()"]);
+    insta::assert_snapshot!(stdout, @r###"
+    @ 2001-02-03 04:05:09.000 +07:00
+    o 2001-02-03 04:05:07.000 +07:00
+    o 1970-01-01 00:00:00.000 +00:00
+    "###);
+}
+
+#[test]
+fn test_log_author_timestamp_ago() {
+    let test_env = TestEnvironment::default();
+    test_env.jj_cmd_success(test_env.env_root(), &["init", "repo", "--git"]);
+    let repo_path = test_env.env_root().join("repo");
+
+    test_env.jj_cmd_success(&repo_path, &["describe", "-m", "first"]);
+    test_env.jj_cmd_success(&repo_path, &["new", "-m", "second"]);
+
+    let stdout = test_env.jj_cmd_success(&repo_path, &["log", "-T", "author.timestamp().ago()"]);
+    let line_re = Regex::new(r"@|o [0-9]+ years ago").unwrap();
+    assert!(
+        stdout.lines().all(|x| line_re.is_match(x)),
+        "expected every line to match regex"
+    );
+}

tests/test_log_command.rs

@@ -13,7 +13,6 @@
 // limitations under the License.
 
 use common::{get_stderr_string, get_stdout_string, TestEnvironment};
-use regex::Regex;
 
 pub mod common;
 
@@ -550,37 +549,3 @@ fn test_default_revset_per_repo() {
             .count()
     );
 }
-
-#[test]
-fn test_log_author_timestamp() {
-    let test_env = TestEnvironment::default();
-    test_env.jj_cmd_success(test_env.env_root(), &["init", "repo", "--git"]);
-    let repo_path = test_env.env_root().join("repo");
-
-    test_env.jj_cmd_success(&repo_path, &["describe", "-m", "first"]);
-    test_env.jj_cmd_success(&repo_path, &["new", "-m", "second"]);
-
-    let stdout = test_env.jj_cmd_success(&repo_path, &["log", "-T", "author.timestamp()"]);
-    insta::assert_snapshot!(stdout, @r###"
-    @ 2001-02-03 04:05:09.000 +07:00
-    o 2001-02-03 04:05:07.000 +07:00
-    o 1970-01-01 00:00:00.000 +00:00
-    "###);
-}
-
-#[test]
-fn test_log_author_timestamp_ago() {
-    let test_env = TestEnvironment::default();
-    test_env.jj_cmd_success(test_env.env_root(), &["init", "repo", "--git"]);
-    let repo_path = test_env.env_root().join("repo");
-
-    test_env.jj_cmd_success(&repo_path, &["describe", "-m", "first"]);
-    test_env.jj_cmd_success(&repo_path, &["new", "-m", "second"]);
-
-    let stdout = test_env.jj_cmd_success(&repo_path, &["log", "-T", "author.timestamp().ago()"]);
-    let line_re = Regex::new(r"@|o [0-9]+ years ago").unwrap();
-    assert!(
-        stdout.lines().all(|x| line_re.is_match(x)),
-        "expected every line to match regex"
-    );
-}