Implement jj sign command

cli/src/commands/mod.rs

@@ -45,6 +45,7 @@ mod restore;
 mod root;
 mod run;
 mod show;
+mod sign;
 mod simplify_parents;
 mod sparse;
 mod split;
@@ -128,6 +129,7 @@ enum Command {
     // TODO: Flesh out.
     Run(run::RunArgs),
     Show(show::ShowArgs),
+    Sign(sign::SignArgs),
     SimplifyParents(simplify_parents::SimplifyParentsArgs),
     #[command(subcommand)]
     Sparse(sparse::SparseCommand),
@@ -207,6 +209,7 @@ pub fn run_command(ui: &mut Ui, command_helper: &CommandHelper) -> Result<(), Co
             simplify_parents::cmd_simplify_parents(ui, command_helper, args)
         }
         Command::Show(args) => show::cmd_show(ui, command_helper, args),
+        Command::Sign(args) => sign::cmd_sign(ui, command_helper, args),
         Command::Sparse(args) => sparse::cmd_sparse(ui, command_helper, args),
         Command::Split(args) => split::cmd_split(ui, command_helper, args),
         Command::Squash(args) => squash::cmd_squash(ui, command_helper, args),

cli/src/commands/sign.rs

@@ -0,0 +1,118 @@
+// 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 clap_complete::ArgValueCandidates;
+use itertools::Itertools;
+use jj_lib::commit::Commit;
+use jj_lib::commit::CommitIteratorExt;
+use jj_lib::signing::SignBehavior;
+
+use crate::cli_util::CommandHelper;
+use crate::cli_util::RevisionArg;
+use crate::command_error::user_error;
+use crate::command_error::CommandError;
+use crate::complete;
+use crate::ui::Ui;
+
+/// Cryptographically sign a revision
+#[derive(clap::Args, Clone, Debug)]
+pub struct SignArgs {
+    /// What key to use, depends on the configured signing backend.
+    #[arg()]
+    key: Option<String>,
+    /// What revision(s) to sign
+    #[arg(
+        long, short,
+        default_value = "@",
+        value_name = "REVSETS",
+        add = ArgValueCandidates::new(complete::mutable_revisions),
+    )]
+    revisions: Vec<RevisionArg>,
+    /// Sign a commit that is not authored by you or was already signed.
+    #[arg(long, short)]
+    force: bool,
+    /// Drop the signature, explicitly "un-signing" the commit.
+    #[arg(long, short = 'D', conflicts_with = "force")]
+    drop: bool,
+}
+
+pub fn cmd_sign(ui: &mut Ui, command: &CommandHelper, args: &SignArgs) -> Result<(), CommandError> {
+    let mut workspace_command = command.workspace_helper(ui)?;
+
+    let commits: Vec<Commit> = workspace_command
+        .parse_union_revsets(ui, &args.revisions)?
+        .evaluate_to_commits()?
+        .try_collect()?;
+
+    let commit_ids = commits.iter().ids().collect_vec();
+    workspace_command.check_rewritable(commit_ids)?;
+
+    for commit in &commits {
+        if !args.force {
+            if !args.drop && commit.is_signed() {
+                return Err(user_error(
+                    "Commit is already signed, use --force to sign anyway",
+                ));
+            }
+            if commit.author().email != command.settings().user_email() {
+                return Err(user_error(
+                    "Commit is not authored by you, use --force to sign anyway",
+                ));
+            }
+        }
+    }
+
+    let mut tx = workspace_command.start_transaction();
+
+    let behavior = if args.drop {
+        SignBehavior::Drop
+    } else if args.force {
+        SignBehavior::Force
+    } else {
+        SignBehavior::Own
+    };
+    let mut signed_commits = vec![];
+    tx.repo_mut().transform_descendants(
+        commits.iter().ids().cloned().collect_vec(),
+        |rewriter| {
+            if commits.contains(rewriter.old_commit()) {
+                let commit_builder = rewriter.rebase()?;
+                let new_commit = commit_builder
+                    .set_sign_key(args.key.clone())
+                    .set_sign_behavior(behavior)
+                    .write()?;
+                signed_commits.push(new_commit);
+            }
+            Ok(())
+        },
+    )?;
+
+    tx.finish(ui, format!("signed {} commits", signed_commits.len()))?;
+
+    let Some(mut formatter) = ui.status_formatter() else {
+        return Ok(());
+    };
+    let template = workspace_command.commit_summary_template();
+    for commit in &signed_commits {
+        if args.drop {
+            write!(formatter, "Signature was dropped: ")?;
+        } else {
+            write!(formatter, "Commit was signed: ")?;
+        }
+        template.format(commit, formatter.as_mut())?;
+        writeln!(formatter)?;
+    }
+
+    Ok(())
+}

cli/tests/cli-reference@.md.snap

@@ -1,6 +1,7 @@
 ---
 source: cli/tests/test_generate_md_cli_help.rs
 description: "AUTO-GENERATED FILE, DO NOT EDIT. This cli reference is generated by a test as an `insta` snapshot. MkDocs includes this snapshot from docs/cli-reference.md."
+snapshot_kind: text
 ---
 <!-- BEGIN MARKDOWN-->
 
@@ -79,6 +80,7 @@ This document contains the help content for the `jj` command-line program.
 * [`jj restore`↴](#jj-restore)
 * [`jj root`↴](#jj-root)
 * [`jj show`↴](#jj-show)
+* [`jj sign`↴](#jj-sign)
 * [`jj simplify-parents`↴](#jj-simplify-parents)
 * [`jj sparse`↴](#jj-sparse)
 * [`jj sparse edit`↴](#jj-sparse-edit)
@@ -149,6 +151,7 @@ To get started, see the tutorial at https://jj-vcs.github.io/jj/latest/tutorial/
 * `restore` — Restore paths from another revision
 * `root` — Show the current workspace root directory
 * `show` — Show commit description and changes in a revision
+* `sign` — Cryptographically sign a revision
 * `simplify-parents` — Simplify parent edges for the specified revision(s)
 * `sparse` — Manage which paths from the working-copy commit are present in the working copy
 * `split` — Split a revision in two
@@ -1982,6 +1985,26 @@ Show commit description and changes in a revision
 
 
 
+## `jj sign`
+
+Cryptographically sign a revision
+
+**Usage:** `jj sign [OPTIONS] [KEY]`
+
+###### **Arguments:**
+
+* `<KEY>` — What key to use, depends on the configured signing backend
+
+###### **Options:**
+
+* `-r`, `--revisions <REVSETS>` — What revision(s) to sign
+
+  Default value: `@`
+* `-f`, `--force` — Sign a commit that is not authored by you or was already signed
+* `-D`, `--drop` — Drop the signature, explicitly "un-signing" the commit
+
+
+
 ## `jj simplify-parents`
 
 Simplify parent edges for the specified revision(s).

cli/tests/runner.rs

@@ -63,6 +63,7 @@ mod test_revset_output;
 mod test_root;
 mod test_shell_completion;
 mod test_show_command;
+mod test_sign_command;
 mod test_simplify_parents_command;
 mod test_sparse_command;
 mod test_split_command;

cli/tests/test_sign_command.rs

@@ -0,0 +1,170 @@
+// 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 crate::common::TestEnvironment;
+
+#[test]
+fn test_sign() {
+    let test_env = TestEnvironment::default();
+
+    test_env.add_config(
+        r#"
+[signing]
+sign-all = false
+backend = "test"
+"#,
+    );
+
+    test_env.jj_cmd_ok(test_env.env_root(), &["git", "init", "repo"]);
+    let repo_path = test_env.env_root().join("repo");
+    test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "init"]);
+
+    let template = r#"if(signature,
+                         signature.status() ++ " " ++ signature.display(),
+                         "no"
+                      ) ++ " signature""#;
+
+    let show_no_sig = test_env.jj_cmd_success(&repo_path, &["show", "-T", template, "-r", "@-"]);
+    insta::assert_snapshot!(show_no_sig, @"no signature");
+
+    let (_, stderr) = test_env.jj_cmd_ok(&repo_path, &["sign", "-r", "@-"]);
+    insta::assert_snapshot!(stderr, @r"
+    Rebased 1 descendant commits
+    Working copy now at: rlvkpnrz 1c141424 (empty) (no description set)
+    Parent commit      : qpvuntsm a9cc7c27 (empty) init
+    Commit was signed: qpvuntsm a9cc7c27 (empty) init
+    ");
+
+    let show_with_sig = test_env.jj_cmd_success(&repo_path, &["show", "-T", template, "-r", "@-"]);
+    insta::assert_snapshot!(show_with_sig, @r"good test-display signature");
+}
+
+#[test]
+fn test_sig_drop() {
+    let test_env = TestEnvironment::default();
+
+    test_env.add_config(
+        r#"
+[signing]
+sign-all = false
+backend = "test"
+"#,
+    );
+
+    test_env.jj_cmd_ok(test_env.env_root(), &["git", "init", "repo"]);
+    let repo_path = test_env.env_root().join("repo");
+    test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "init"]);
+
+    let template = r#"if(signature,
+                         signature.status() ++ " " ++ signature.display(),
+                         "no"
+                      ) ++ " signature""#;
+
+    let show_no_sig = test_env.jj_cmd_success(&repo_path, &["show", "-T", template, "-r", "@-"]);
+    insta::assert_snapshot!(show_no_sig, @"no signature");
+
+    test_env.jj_cmd_ok(&repo_path, &["sign", "-r", "@-"]);
+
+    let show_with_sig = test_env.jj_cmd_success(&repo_path, &["show", "-T", template, "-r", "@-"]);
+    insta::assert_snapshot!(show_with_sig, @"good test-display signature");
+
+    let (_, stderr) = test_env.jj_cmd_ok(&repo_path, &["sign", "-r", "@-", "--drop"]);
+    insta::assert_snapshot!(stderr, @r"
+    Rebased 1 descendant commits
+    Working copy now at: rlvkpnrz be42f24a (empty) (no description set)
+    Parent commit      : qpvuntsm 755eae8e (empty) init
+    Signature was dropped: qpvuntsm 755eae8e (empty) init
+    ");
+
+    let show_with_sig = test_env.jj_cmd_success(&repo_path, &["show", "-T", template, "-r", "@-"]);
+    insta::assert_snapshot!(show_with_sig, @"no signature");
+}
+
+#[test]
+fn test_commit_already_signed() {
+    let test_env = TestEnvironment::default();
+
+    test_env.add_config(
+        r#"
+[signing]
+sign-all = false
+backend = "test"
+"#,
+    );
+
+    test_env.jj_cmd_ok(test_env.env_root(), &["git", "init", "repo"]);
+    let repo_path = test_env.env_root().join("repo");
+    test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "init"]);
+
+    test_env.jj_cmd_ok(&repo_path, &["sign", "-r", "@-"]);
+    let stderr = test_env.jj_cmd_failure(&repo_path, &["sign", "-r", "@-"]);
+    insta::assert_snapshot!(stderr, @"Error: Commit is already signed, use --force to sign anyway");
+}
+
+#[test]
+fn test_force_sign() {
+    let test_env = TestEnvironment::default();
+
+    test_env.add_config(
+        r#"
+[signing]
+sign-all = false
+backend = "test"
+"#,
+    );
+
+    test_env.jj_cmd_ok(test_env.env_root(), &["git", "init", "repo"]);
+    let repo_path = test_env.env_root().join("repo");
+    test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "init"]);
+
+    test_env.jj_cmd_ok(&repo_path, &["sign", "-r", "@-"]);
+    let (_, stderr) = test_env.jj_cmd_ok(&repo_path, &["sign", "--force", "-r", "@-"]);
+    insta::assert_snapshot!(stderr, @r"
+    Rebased 1 descendant commits
+    Working copy now at: rlvkpnrz 1c141424 (empty) (no description set)
+    Parent commit      : qpvuntsm a9cc7c27 (empty) init
+    Commit was signed: qpvuntsm a9cc7c27 (empty) init
+    ");
+}
+
+#[test]
+fn test_different_author() {
+    let test_env = TestEnvironment::default();
+
+    test_env.add_config(
+        r#"
+[signing]
+sign-all = false
+backend = "test"
+"#,
+    );
+
+    test_env.jj_cmd_ok(test_env.env_root(), &["git", "init", "repo"]);
+    let repo_path = test_env.env_root().join("repo");
+    test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "init"]);
+
+    test_env.jj_cmd_ok(
+        &repo_path,
+        &[
+            "desc",
+            "--author",
+            "Someone Else <[email protected]>",
+            "-m",
+            "init",
+            "@-",
+        ],
+    );
+    let stderr = test_env.jj_cmd_failure(&repo_path, &["sign", "-r", "@-"]);
+    insta::assert_snapshot!(stderr, @"Error: Commit is not authored by you, use --force to sign anyway");
+}

lib/src/commit_builder.rs

@@ -332,7 +332,9 @@ impl DetachedCommitBuilder {
     }
 
     pub fn set_sign_key(&mut self, sign_key: Option<String>) -> &mut Self {
-        self.sign_settings.key = sign_key;
+        if sign_key.is_some() {
+            self.sign_settings.key = sign_key;
+        }
         self
     }