fake-editor: replace expectpath with dump-path

This allows us to assert the expected path in the test itself, rather
than in the fake editor.

cli/testing/fake-editor.rs

@@ -50,6 +50,11 @@ fn main() {
                 let dest_path = edit_script_path.parent().unwrap().join(dest);
                 fs::copy(&args.file, dest_path).unwrap();
             }
+            ["dump-path", dest] => {
+                let dest_path = edit_script_path.parent().unwrap().join(dest);
+                fs::write(&dest_path, args.file.to_str().unwrap())
+                    .unwrap_or_else(|err| panic!("Failed to write file {dest_path:?}: {err}"));
+            }
             ["expect"] => {
                 let actual = String::from_utf8(fs::read(&args.file).unwrap()).unwrap();
                 if actual != payload {
@@ -58,14 +63,6 @@ fn main() {
                     exit(1)
                 }
             }
-            ["expectpath"] => {
-                let actual = args.file.to_str().unwrap();
-                if actual != payload {
-                    eprintln!("fake-editor: Unexpected path.\n");
-                    eprintln!("EXPECTED: <{payload}>\nRECEIVED: <{actual}>");
-                    exit(1)
-                }
-            }
             ["write"] => {
                 fs::write(&args.file, payload).unwrap_or_else(|_| {
                     panic!("Failed to write file {}", args.file.to_str().unwrap())

cli/tests/test_config_command.rs

@@ -12,6 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use std::path::Path;
+
 use insta::assert_snapshot;
 use itertools::Itertools;
 use regex::Regex;
@@ -621,12 +623,12 @@ fn test_config_edit_user() {
     let repo_path = test_env.env_root().join("repo");
     let edit_script = test_env.set_up_fake_editor();
 
-    std::fs::write(
-        edit_script,
-        format!("expectpath\n{}", test_env.config_path().to_str().unwrap()),
-    )
-    .unwrap();
+    std::fs::write(edit_script, "dump-path path").unwrap();
     test_env.jj_cmd_ok(&repo_path, &["config", "edit", "--user"]);
+
+    let edited_path = std::fs::read_to_string(test_env.env_root().join("path")).unwrap();
+    let edited_path = Path::new(&edited_path);
+    assert_eq!(edited_path, test_env.config_path());
 }
 
 #[test]
@@ -636,15 +638,12 @@ fn test_config_edit_repo() {
     let repo_path = test_env.env_root().join("repo");
     let edit_script = test_env.set_up_fake_editor();
 
-    std::fs::write(
-        edit_script,
-        format!(
-            "expectpath\n{}",
-            repo_path.join(".jj/repo/config.toml").to_str().unwrap()
-        ),
-    )
-    .unwrap();
+    std::fs::write(edit_script, "dump-path path").unwrap();
     test_env.jj_cmd_ok(&repo_path, &["config", "edit", "--repo"]);
+
+    let edited_path = std::fs::read_to_string(test_env.env_root().join("path")).unwrap();
+    let edited_path = Path::new(&edited_path);
+    assert_eq!(edited_path, repo_path.join(".jj/repo/config.toml"));
 }
 
 #[test]