cli: implement enough of jj fix to run a single tool on all files

cli/Cargo.toml

@@ -75,6 +75,7 @@ once_cell = { workspace = true }
 pest = { workspace = true }
 pest_derive = { workspace = true }
 pollster = { workspace = true }
+rayon = { workspace = true }
 regex = { workspace = true }
 rpassword = { workspace = true }
 scm-record = { workspace = true }

cli/src/commands/mod.rs

@@ -93,7 +93,6 @@ enum Command {
     Duplicate(duplicate::DuplicateArgs),
     Edit(edit::EditArgs),
     Files(files::FilesArgs),
-    #[command(hide = true)]
     Fix(fix::FixArgs),
     #[command(subcommand)]
     Git(git::GitCommand),

cli/src/config-schema.json

@@ -482,6 +482,16 @@
                     "additionalProperties": true
                 }
             }
+        },
+	"fix": {
+            "type": "object",
+            "description": "Settings for jj fix",
+            "properties": {
+                "tool-command": {
+                    "type": "string",
+                    "description": "Shell command that takes file content on stdin and returns fixed file content on stdout"
+                }
+            }
         }
     }
 }

cli/testing/fake-formatter.rs

@@ -36,7 +36,7 @@ struct Args {
     #[arg(long, default_value_t = false)]
     fail: bool,
 
-    /// Reverse the characters in each line when reading stdin
+    /// Reverse the characters in each line when reading stdin.
     #[arg(long, default_value_t = false)]
     reverse: bool,
 

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

@@ -37,6 +37,7 @@ This document contains the help content for the `jj` command-line program.
 * [`jj duplicate`↴](#jj-duplicate)
 * [`jj edit`↴](#jj-edit)
 * [`jj files`↴](#jj-files)
+* [`jj fix`↴](#jj-fix)
 * [`jj git`↴](#jj-git)
 * [`jj git remote`↴](#jj-git-remote)
 * [`jj git remote add`↴](#jj-git-remote-add)
@@ -118,6 +119,7 @@ To get started, see the tutorial at https://github.com/martinvonz/jj/blob/main/d
 * `duplicate` — Create a new change with the same content as an existing one
 * `edit` — Sets the specified revision as the working-copy revision
 * `files` — List files in a revision
+* `fix` — Update files with formatting fixes or other changes
 * `git` — Commands for working with the underlying Git repo
 * `init` — Create a new repo in the given directory
 * `interdiff` — Compare the changes of two commits
@@ -760,6 +762,24 @@ List files in a revision
 
 
 
+## `jj fix`
+
+Update files with formatting fixes or other changes
+
+The primary use case for this command is to apply the results of automatic code formatting tools to revisions that may not be properly formatted yet. It can also be used to modify files with other tools like `sed` or `sort`.
+
+The changed files in the given revisions will be updated with any fixes determined by passing their file content through the external tool. Descendants will also be updated by passing their versions of the same files through the same external tool, which will never result in new conflicts. Files with existing conflicts will be updated on all sides of the conflict, which can potentially increase or decrease the number of conflict markers.
+
+The external tool must accept the current file content on standard input, and return the updated file content on standard output. The output will not be used unless the tool exits with a successful exit code. Output on standard error will be ignored.
+
+**Usage:** `jj fix [OPTIONS]`
+
+###### **Options:**
+
+* `-s`, `--sources <SOURCES>` — Fix files in the specified revision(s) and their descendants
+
+
+
 ## `jj git`
 
 Commands for working with the underlying Git repo

cli/tests/runner.rs

@@ -26,6 +26,7 @@ mod test_diff_command;
 mod test_diffedit_command;
 mod test_duplicate_command;
 mod test_edit_command;
+mod test_fix_command;
 mod test_generate_md_cli_help;
 mod test_git_clone;
 mod test_git_colocated;