cli: implement workspace add --sparse-patterns

This flag implements three modes:

- `copy`: copy sparse patterns from parent
- `full`: do not copy sparse patterns from parent
- `empty`: clear all paths, equal to `set --clear`

This is useful for various tooling like tools that want to run a parallel
process that queries the build system (without running into locks/blocking.)

I think continuing to copy sparse patterns makes sense as the default behavior.

Signed-off-by: Austin Seipp <aseipp@pobox.com>

CHANGELOG.md

@@ -24,6 +24,11 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
   can be used to more easily introduce automatic formatting changes in a new
   commit separate from other changes.
 
+* `jj workspace add` now accepts a `--sparse-patterns=<MODE>` option, which
+  allows control of the sparse patterns for a newly created workspace: `copy`
+  (inherit from parent; default), `full` (full working copy), or `empty` (the
+  empty working copy).
+
 ### Fixed bugs
 
  * Fixed panic when parsing invalid conflict markers of a particular form.

cli/src/commands/workspace/add.rs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use std::fmt::Display;
 use std::fs;
 
 use itertools::Itertools;
@@ -31,9 +32,31 @@ use crate::command_error::user_error;
 use crate::command_error::CommandError;
 use crate::ui::Ui;
 
+/// How to handle sparse patterns when creating a new workspace.
+#[derive(clap::ValueEnum, Clone, Debug, Eq, PartialEq)]
+enum SparseInheritance {
+    /// Copy all sparse patterns from the current workspace.
+    Copy,
+    /// Include all files in the new workspace.
+    Full,
+    /// Clear all files from the workspace (it will be empty).
+    Empty,
+}
+
+impl Display for SparseInheritance {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            SparseInheritance::Copy => write!(f, "copy"),
+            SparseInheritance::Full => write!(f, "full"),
+            SparseInheritance::Empty => write!(f, "empty"),
+        }
+    }
+}
+
 /// Add a workspace
 ///
-/// Sparse patterns will be copied over from the current workspace.
+/// By default, the new workspace inherits the sparse patterns of the current
+/// workspace. You can override this with the `--sparse-patterns` option.
 #[derive(clap::Args, Clone, Debug)]
 pub struct WorkspaceAddArgs {
     /// Where to create the new workspace
@@ -58,6 +81,9 @@ pub struct WorkspaceAddArgs {
     /// new r1 r2 r3 ...`.
     #[arg(long, short)]
     revision: Vec<RevisionArg>,
+    /// How to handle sparse patterns when creating a new workspace.
+    #[arg(long, default_value_t=SparseInheritance::Copy)]
+    sparse_patterns: SparseInheritance,
 }
 
 #[instrument(skip_all)]
@@ -114,19 +140,29 @@ pub fn cmd_workspace_add(
         )?;
     }
 
-    // Copy sparse patterns from workspace where the command was run
     let mut new_workspace_command = command.for_workable_repo(ui, new_workspace, repo)?;
-    let (mut locked_ws, _wc_commit) = new_workspace_command.start_working_copy_mutation()?;
-    let sparse_patterns = old_workspace_command
-        .working_copy()
-        .sparse_patterns()?
-        .to_vec();
-    locked_ws
-        .locked_wc()
-        .set_sparse_patterns(sparse_patterns)
-        .map_err(|err| internal_error_with_message("Failed to set sparse patterns", err))?;
-    let operation_id = locked_ws.locked_wc().old_operation_id().clone();
-    locked_ws.finish(operation_id)?;
+
+    let sparsity = match args.sparse_patterns {
+        SparseInheritance::Full => None,
+        SparseInheritance::Empty => Some(vec![]),
+        SparseInheritance::Copy => {
+            let sparse_patterns = old_workspace_command
+                .working_copy()
+                .sparse_patterns()?
+                .to_vec();
+            Some(sparse_patterns)
+        }
+    };
+
+    if let Some(sparse_patterns) = sparsity {
+        let (mut locked_ws, _wc_commit) = new_workspace_command.start_working_copy_mutation()?;
+        locked_ws
+            .locked_wc()
+            .set_sparse_patterns(sparse_patterns)
+            .map_err(|err| internal_error_with_message("Failed to set sparse patterns", err))?;
+        let operation_id = locked_ws.locked_wc().old_operation_id().clone();
+        locked_ws.finish(operation_id)?;
+    }
 
     let mut tx = new_workspace_command.start_transaction();
 

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

@@ -2118,7 +2118,7 @@ Each workspace also has own sparse patterns.
 
 Add a workspace
 
-Sparse patterns will be copied over from the current workspace.
+By default, the new workspace inherits the sparse patterns of the current workspace. You can override this with the `--sparse-patterns` option.
 
 **Usage:** `jj workspace add [OPTIONS] <DESTINATION>`
 
@@ -2136,6 +2136,18 @@ Sparse patterns will be copied over from the current workspace.
    If no revisions are specified, the new workspace will be created, and its working-copy commit will exist on top of the parent(s) of the working-copy commit in the current workspace, i.e. they will share the same parent(s).
 
    If any revisions are specified, the new workspace will be created, and the new working-copy commit will be created with all these revisions as parents, i.e. the working-copy commit will exist as if you had run `jj new r1 r2 r3 ...`.
+* `--sparse-patterns <SPARSE_PATTERNS>` — How to handle sparse patterns when creating a new workspace
+
+  Default value: `copy`
+
+  Possible values:
+  - `copy`:
+    Copy all sparse patterns from the current workspace
+  - `full`:
+    Include all files in the new workspace
+  - `empty`:
+    Clear all files from the workspace (it will be empty)
+
 
 
 

cli/tests/test_workspaces.rs

@@ -77,6 +77,9 @@ fn test_workspaces_sparse_patterns() {
     let ws1_path = test_env.env_root().join("ws1");
     let ws2_path = test_env.env_root().join("ws2");
     let ws3_path = test_env.env_root().join("ws3");
+    let ws4_path = test_env.env_root().join("ws4");
+    let ws5_path = test_env.env_root().join("ws5");
+    let ws6_path = test_env.env_root().join("ws6");
 
     test_env.jj_cmd_ok(&ws1_path, &["sparse", "set", "--clear", "--add=foo"]);
     test_env.jj_cmd_ok(&ws1_path, &["workspace", "add", "../ws2"]);
@@ -91,6 +94,30 @@ fn test_workspaces_sparse_patterns() {
     bar
     foo
     "###);
+    // --sparse-patterns behavior
+    test_env.jj_cmd_ok(
+        &ws3_path,
+        &["workspace", "add", "--sparse-patterns=copy", "../ws4"],
+    );
+    let stdout = test_env.jj_cmd_success(&ws4_path, &["sparse", "list"]);
+    insta::assert_snapshot!(stdout, @r###"
+    bar
+    foo
+    "###);
+    test_env.jj_cmd_ok(
+        &ws3_path,
+        &["workspace", "add", "--sparse-patterns=full", "../ws5"],
+    );
+    let stdout = test_env.jj_cmd_success(&ws5_path, &["sparse", "list"]);
+    insta::assert_snapshot!(stdout, @r###"
+    .
+    "###);
+    test_env.jj_cmd_ok(
+        &ws3_path,
+        &["workspace", "add", "--sparse-patterns=empty", "../ws6"],
+    );
+    let stdout = test_env.jj_cmd_success(&ws6_path, &["sparse", "list"]);
+    insta::assert_snapshot!(stdout, @"");
 }
 
 /// Test adding a second workspace while the current workspace is editing a