From f21a069a472bf80c2284963daec07e0dbe0d5e6a Mon Sep 17 00:00:00 2001
From: Martin von Zweigbergk <martinvonz@google.com>
Date: Thu, 31 Mar 2022 23:44:28 -0700
Subject: [PATCH] tests: add tests for `jj restore -i`

---
 Cargo.toml                    |  4 ++
 testing/fake-diff-editor.rs   | 61 +++++++++++++++++++++++++
 tests/common/mod.rs           | 23 ++++++++++
 tests/test_restore_command.rs | 86 +++++++++++++++++++++++++++++++++++
 4 files changed, 174 insertions(+)
 create mode 100644 testing/fake-diff-editor.rs

diff --git a/Cargo.toml b/Cargo.toml
index 8440f239b..94c873721 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -16,6 +16,10 @@ categories = ["command-line-utilities", "development-tools"]
 name = "jj"
 path = "src/main.rs"
 
+[[bin]]
+name = "fake-diff-editor"
+path = "testing/fake-diff-editor.rs"
+
 [[bench]]
 name = "diff_bench"
 harness = false
diff --git a/testing/fake-diff-editor.rs b/testing/fake-diff-editor.rs
new file mode 100644
index 000000000..13cd5d5c0
--- /dev/null
+++ b/testing/fake-diff-editor.rs
@@ -0,0 +1,61 @@
+// 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 diff-editor, useful for testing
+#[derive(Parser, Debug)]
+#[clap()]
+struct Args {
+    /// Path to the "before" directory
+    before: PathBuf,
+
+    /// Path to the "after" directory
+    after: 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),
+            ["rm", file] => {
+                std::fs::remove_file(args.after.join(file)).unwrap();
+            }
+            ["reset", file] => {
+                if args.before.join(file).exists() {
+                    std::fs::copy(&args.before.join(file), &args.after.join(file)).unwrap();
+                } else {
+                    std::fs::remove_file(args.after.join(file)).unwrap();
+                }
+            }
+            ["write", file] => {
+                std::fs::write(args.after.join(file), payload).unwrap();
+            }
+            _ => {
+                eprintln!("unexpected command: {}", command);
+                exit(1)
+            }
+        }
+    }
+}
diff --git a/tests/common/mod.rs b/tests/common/mod.rs
index b04bc8ceb..9e8fabe57 100644
--- a/tests/common/mod.rs
+++ b/tests/common/mod.rs
@@ -108,6 +108,29 @@ impl TestEnvironment {
     pub fn add_env_var(&mut self, key: &str, val: &str) {
         self.env_vars.insert(key.to_string(), val.to_string());
     }
+
+    /// 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 {
+        let diff_editor_path = assert_cmd::cargo::cargo_bin("fake-diff-editor");
+        assert!(diff_editor_path.is_file());
+        // Simplified TOML escaping, hoping that there are no '"' or control characters
+        // in it
+        let escaped_diff_editor_path = diff_editor_path.to_str().unwrap().replace('\\', r"\\");
+        self.write_config(
+            format!(
+                r###"
+        [ui]
+        diff-editor = "{}"
+        "###,
+                escaped_diff_editor_path
+            )
+            .as_bytes(),
+        );
+        let edit_script = self.env_root().join("edit_script");
+        self.add_env_var("EDIT_SCRIPT", edit_script.to_str().unwrap());
+        edit_script
+    }
 }
 
 pub fn get_stdout_string(assert: &assert_cmd::assert::Assert) -> String {
diff --git a/tests/test_restore_command.rs b/tests/test_restore_command.rs
index 56c0b5e39..575b2c6fc 100644
--- a/tests/test_restore_command.rs
+++ b/tests/test_restore_command.rs
@@ -84,3 +84,89 @@ fn test_restore() {
     insta::assert_snapshot!(stdout, @"R file1
 ");
 }
+
+#[test]
+fn test_restore_interactive() {
+    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");
+
+    std::fs::write(repo_path.join("file1"), "a\n").unwrap();
+    std::fs::write(repo_path.join("file2"), "a\n").unwrap();
+    test_env.jj_cmd_success(&repo_path, &["new"]);
+    std::fs::remove_file(repo_path.join("file1")).unwrap();
+    std::fs::write(repo_path.join("file2"), "b\n").unwrap();
+    std::fs::write(repo_path.join("file3"), "b\n").unwrap();
+
+    let edit_script = test_env.set_up_fake_diff_editor();
+
+    // Nothing happens if we make no changes
+    std::fs::write(&edit_script, "").unwrap();
+    let stdout = test_env.jj_cmd_success(&repo_path, &["restore", "-i"]);
+    insta::assert_snapshot!(stdout, @"Nothing changed.
+");
+    let stdout = test_env.jj_cmd_success(&repo_path, &["diff", "-s"]);
+    insta::assert_snapshot!(stdout, @r###"
+    R file1
+    M file2
+    A file3
+    "###);
+
+    // Nothing happens if the diff-editor exits with an error
+    std::fs::write(&edit_script, "rm file2\0fail").unwrap();
+    let stdout = test_env.jj_cmd_failure(&repo_path, &["restore", "-i"]);
+    insta::assert_snapshot!(stdout, @"Error: Failed to edit diff: The diff tool exited with a non-zero code
+");
+    let stdout = test_env.jj_cmd_success(&repo_path, &["diff", "-s"]);
+    insta::assert_snapshot!(stdout, @r###"
+    R file1
+    M file2
+    A file3
+    "###);
+
+    // Can restore changes to individual files
+    std::fs::write(&edit_script, "reset file2\0reset file3").unwrap();
+    let stdout = test_env.jj_cmd_success(&repo_path, &["restore", "-i"]);
+    insta::assert_snapshot!(stdout, @r###"
+    Created abdbf6271a1c 
+    Working copy now at: abdbf6271a1c 
+    Added 0 files, modified 1 files, removed 1 files
+    "###);
+    let stdout = test_env.jj_cmd_success(&repo_path, &["diff", "-s"]);
+    insta::assert_snapshot!(stdout, @"R file1
+");
+
+    // Can make unrelated edits
+    test_env.jj_cmd_success(&repo_path, &["undo"]);
+    std::fs::write(&edit_script, "write file3\nunrelated\n").unwrap();
+    let stdout = test_env.jj_cmd_success(&repo_path, &["restore", "-i"]);
+    insta::assert_snapshot!(stdout, @r###"
+    Created e31f7f33ad07 
+    Working copy now at: e31f7f33ad07 
+    Added 0 files, modified 1 files, removed 0 files
+    "###);
+    let stdout = test_env.jj_cmd_success(&repo_path, &["diff", "--git"]);
+    insta::assert_snapshot!(stdout, @r###"
+    diff --git a/file1 b/file1
+    deleted file mode 100644
+    index 7898192261..0000000000
+    --- a/file1
+    +++ /dev/null
+    @@ -1,1 +1,0 @@
+    -a
+    diff --git a/file2 b/file2
+    index 7898192261...6178079822 100644
+    --- a/file2
+    +++ b/file2
+    @@ -1,1 +1,1 @@
+    -a
+    +b
+    diff --git a/file3 b/file3
+    new file mode 100644
+    index 0000000000..c21c9352f7
+    --- /dev/null
+    +++ b/file3
+    @@ -1,0 +1,1 @@
+    +unrelated
+    "###);
+}