tests: add tests for jj describe

Cargo.toml

@@ -16,6 +16,10 @@ categories = ["command-line-utilities", "development-tools"]
 name = "jj"
 path = "src/main.rs"
 
+[[bin]]
+name = "fake-editor"
+path = "testing/fake-editor.rs"
+
 [[bin]]
 name = "fake-diff-editor"
 path = "testing/fake-diff-editor.rs"

testing/fake-diff-editor.rs

@@ -48,7 +48,7 @@ fn files_recursively(dir: &PathBuf) -> HashSet<String> {
 
 fn main() {
     let args: Args = Args::parse();
-    let edit_script_path = PathBuf::from(std::env::var_os("EDIT_SCRIPT").unwrap());
+    let edit_script_path = PathBuf::from(std::env::var_os("DIFF_EDIT_SCRIPT").unwrap());
     let edit_script = String::from_utf8(std::fs::read(&edit_script_path).unwrap()).unwrap();
     for instruction in edit_script.split('\0') {
         let (command, payload) = instruction.split_once('\n').unwrap_or((instruction, ""));

testing/fake-editor.rs

@@ -0,0 +1,49 @@
+// Copyright 2022 Google LLC
+//
+// 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 std::path::PathBuf;
+use std::process::exit;
+
+use clap::Parser;
+use itertools::Itertools;
+
+/// A fake editor, useful for testing
+// It's overkill to use clap for a single argument, but we already use it in many other places...
+#[derive(Parser, Debug)]
+#[clap()]
+struct Args {
+    /// Path to the file to edit
+    file: PathBuf,
+}
+
+fn main() {
+    let args: Args = Args::parse();
+    let edit_script_path = PathBuf::from(std::env::var_os("EDIT_SCRIPT").unwrap());
+    let edit_script = String::from_utf8(std::fs::read(&edit_script_path).unwrap()).unwrap();
+    for instruction in edit_script.split('\0') {
+        let (command, payload) = instruction.split_once('\n').unwrap_or((instruction, ""));
+        let parts = command.split(' ').collect_vec();
+        match parts.as_slice() {
+            [""] => {}
+            ["fail"] => exit(1),
+            ["write"] => {
+                std::fs::write(&args.file, payload).unwrap();
+            }
+            _ => {
+                eprintln!("unexpected command: {}", command);
+                exit(1)
+            }
+        }
+    }
+}

tests/common/mod.rs

@@ -109,6 +109,19 @@ impl TestEnvironment {
         self.env_vars.insert(key.to_string(), val.to_string());
     }
 
+    /// Sets up the fake editor to read an edit script from the returned path
+    pub fn set_up_fake_editor(&mut self) -> PathBuf {
+        let editor_path = assert_cmd::cargo::cargo_bin("fake-editor");
+        assert!(editor_path.is_file());
+        // Simplified TOML escaping, hoping that there are no '"' or control characters
+        // in it
+        let escaped_editor_path = editor_path.to_str().unwrap().replace('\\', r"\\");
+        self.add_env_var("EDITOR", &escaped_editor_path);
+        let edit_script = self.env_root().join("edit_script");
+        self.add_env_var("EDIT_SCRIPT", edit_script.to_str().unwrap());
+        edit_script
+    }
+
     /// Sets up the fake diff-editor to read an edit script from the returned
     /// path
     pub fn set_up_fake_diff_editor(&mut self) -> PathBuf {
@@ -127,8 +140,8 @@ impl TestEnvironment {
             )
             .as_bytes(),
         );
-        let edit_script = self.env_root().join("edit_script");
-        self.add_env_var("EDIT_SCRIPT", edit_script.to_str().unwrap());
+        let edit_script = self.env_root().join("diff_edit_script");
+        self.add_env_var("DIFF_EDIT_SCRIPT", edit_script.to_str().unwrap());
         edit_script
     }
 }

tests/test_describe_command.rs

@@ -0,0 +1,49 @@
+// Copyright 2022 Google LLC
+//
+// 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 crate::common::TestEnvironment;
+
+pub mod common;
+
+#[test]
+fn test_describe() {
+    let mut 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");
+
+    let edit_script = test_env.set_up_fake_editor();
+
+    // Set a description using `-m` flag
+    let stdout = test_env.jj_cmd_success(&repo_path, &["describe", "-m", "description from CLI"]);
+    insta::assert_snapshot!(stdout, @"Working copy now at: 7e0db3b0ad17 description from CLI
+");
+
+    // Test making no changes
+    std::fs::write(&edit_script, "").unwrap();
+    let stdout = test_env.jj_cmd_success(&repo_path, &["describe"]);
+    insta::assert_snapshot!(stdout, @"Working copy now at: 45bfa10db64d description from CLI
+");
+
+    // Set a description in editor
+    std::fs::write(&edit_script, "write\ndescription from editor").unwrap();
+    let stdout = test_env.jj_cmd_success(&repo_path, &["describe"]);
+    insta::assert_snapshot!(stdout, @"Working copy now at: f2ce8f1ad8fa description from editor
+");
+
+    // Lines in editor starting with "JJ: " are ignored
+    std::fs::write(&edit_script, "write\nJJ: ignored\ndescription among comment\nJJ: ignored").unwrap();
+    let stdout = test_env.jj_cmd_success(&repo_path, &["describe"]);
+    insta::assert_snapshot!(stdout, @"Working copy now at: 95664f6316ae description among comment
+");
+}