task: Add task contexts (#8675)

This PR supplements tasks with additional environment variables; ideally
we'll be able to write a task like:
`cargo test -p $ZED_CURRENT_PACKAGE -- $ZED_CURRENT_FUNCTION`
- [x] Flesh out multibuffer interactions
- [x] Add ZED_SYMBOL detection based on tree-sitter queries
- [ ] Add release note and demo
- [x] Figure out a solution for rerun dilemma - should `task: rerun`
reevaluate contexts for tasks?

This PR introduced the following variables:
- ZED_COLUMN - current line column
- ZED_ROW - current line row
and the following, which are available for buffers with associated
files:
- ZED_WORKTREE_ROOT - absolute path to the root of the current worktree.
- ZED_FILE - absolute path to the file
- ZED_SYMBOL - currently selected symbol; should match the last symbol
shown in a symbol breadcrumb (e.g. `mod tests > fn test_task_contexts`
should be equal to ZED_SYMBOL of `test_task_contexts`). Note that this
isn't necessarily a test function or a function at all.

Also, you can use them in `cwd` field of definitions (note though that
we're using https://docs.rs/subst/latest/subst/#features for that, so
don't expect a full shell functionality to work); the syntax should
match up with your typical Unix shell.


Release Notes:

- Added task contexts, which are additional environment variables set by
Zed for task execution; task content is dependent on the state of the
editor at the time the task is spawned.

---------

Co-authored-by: Anthony <anthonyeid7@protonmail.com>

crates/tasks_ui/src/modal.rs

@@ -2,23 +2,36 @@ use std::{path::PathBuf, sync::Arc};
 
 use fuzzy::{StringMatch, StringMatchCandidate};
 use gpui::{
-    actions, rems, AppContext, DismissEvent, EventEmitter, FocusableView, InteractiveElement,
-    Model, ParentElement, Render, SharedString, Styled, Subscription, View, ViewContext,
-    VisualContext, WeakView,
+    actions, impl_actions, rems, AppContext, DismissEvent, EventEmitter, FocusableView,
+    InteractiveElement, Model, ParentElement, Render, SharedString, Styled, Subscription, View,
+    ViewContext, VisualContext, WeakView,
 };
 use picker::{
     highlighted_match_with_paths::{HighlightedMatchWithPaths, HighlightedText},
     Picker, PickerDelegate,
 };
 use project::{Inventory, ProjectPath, TaskSourceKind};
-use task::{oneshot_source::OneshotSource, Task};
+use task::{oneshot_source::OneshotSource, Task, TaskContext};
 use ui::{v_flex, ListItem, ListItemSpacing, RenderOnce, Selectable, WindowContext};
 use util::{paths::PathExt, ResultExt};
 use workspace::{ModalView, Workspace};
 
 use crate::schedule_task;
+use serde::Deserialize;
+actions!(task, [Spawn]);
 
-actions!(task, [Spawn, Rerun]);
+/// Rerun last task
+#[derive(PartialEq, Clone, Deserialize, Default)]
+pub struct Rerun {
+    #[serde(default)]
+    /// Controls whether the task context is reevaluated prior to execution of a task.
+    /// If it is not, environment variables such as ZED_COLUMN, ZED_FILE are gonna be the same as in the last execution of a task
+    /// If it is, these variables will be updated to reflect current state of editor at the time task::Rerun is executed.
+    /// default: false
+    pub reevaluate_context: bool,
+}
+
+impl_actions!(task, [Rerun]);
 
 /// A modal used to spawn new tasks.
 pub(crate) struct TasksModalDelegate {
@@ -28,10 +41,15 @@ pub(crate) struct TasksModalDelegate {
     selected_index: usize,
     workspace: WeakView<Workspace>,
     prompt: String,
+    task_context: TaskContext,
 }
 
 impl TasksModalDelegate {
-    fn new(inventory: Model<Inventory>, workspace: WeakView<Workspace>) -> Self {
+    fn new(
+        inventory: Model<Inventory>,
+        task_context: TaskContext,
+        workspace: WeakView<Workspace>,
+    ) -> Self {
         Self {
             inventory,
             workspace,
@@ -39,6 +57,7 @@ impl TasksModalDelegate {
             matches: Vec::new(),
             selected_index: 0,
             prompt: String::default(),
+            task_context,
         }
     }
 
@@ -79,11 +98,16 @@ pub(crate) struct TasksModal {
 impl TasksModal {
     pub(crate) fn new(
         inventory: Model<Inventory>,
+        task_context: TaskContext,
         workspace: WeakView<Workspace>,
         cx: &mut ViewContext<Self>,
     ) -> Self {
-        let picker = cx
-            .new_view(|cx| Picker::uniform_list(TasksModalDelegate::new(inventory, workspace), cx));
+        let picker = cx.new_view(|cx| {
+            Picker::uniform_list(
+                TasksModalDelegate::new(inventory, task_context, workspace),
+                cx,
+            )
+        });
         let _subscription = cx.subscribe(&picker, |_, _, _, cx| {
             cx.emit(DismissEvent);
         });
@@ -223,7 +247,7 @@ impl PickerDelegate for TasksModalDelegate {
 
         self.workspace
             .update(cx, |workspace, cx| {
-                schedule_task(workspace, task.as_ref(), cx);
+                schedule_task(workspace, task.as_ref(), self.task_context.clone(), cx);
             })
             .ok();
         cx.emit(DismissEvent);
@@ -279,13 +303,12 @@ mod tests {
     use gpui::{TestAppContext, VisualTestContext};
     use project::{FakeFs, Project};
     use serde_json::json;
-    use workspace::AppState;
 
     use super::*;
 
     #[gpui::test]
     async fn test_spawn_tasks_modal_query_reuse(cx: &mut TestAppContext) {
-        init_test(cx);
+        crate::tests::init_test(cx);
         let fs = FakeFs::new(cx.executor());
         fs.insert_tree(
             "/dir",
@@ -431,16 +454,4 @@ mod tests {
                 .collect::<Vec<_>>()
         })
     }
-
-    fn init_test(cx: &mut TestAppContext) -> Arc<AppState> {
-        cx.update(|cx| {
-            let state = AppState::test(cx);
-            language::init(cx);
-            crate::init(cx);
-            editor::init(cx);
-            workspace::init_settings(cx);
-            Project::init_settings(cx);
-            state
-        })
-    }
 }