tasks: Expose captured variables to ContextProvider (#12134)

This PR changes the interface of ContextProvider, allowing it to inspect
*all* variables set so far during the process of building
`TaskVariables`. This makes it possible to capture e.g. an identifier in
tree-sitter query, process it and then export it as a task variable.

Notably, the list of variables includes captures prefixed with leading
underscore; they are removed after all calls to `build_context`, but it
makes it possible to capture something and then conditionally preserve
it (and perhaps modify it).

Release Notes:

- N/A

crates/languages/src/bash.rs

@@ -1,4 +1,4 @@
-use language::ContextProviderWithTasks;
+use project::ContextProviderWithTasks;
 use task::{TaskTemplate, TaskTemplates, VariableName};
 
 pub(super) fn bash_task_context() -> ContextProviderWithTasks {

crates/languages/src/go.rs

@@ -16,7 +16,7 @@ use std::{
     borrow::Cow,
     ffi::{OsStr, OsString},
     ops::Range,
-    path::{Path, PathBuf},
+    path::PathBuf,
     str,
     sync::{
         atomic::{AtomicBool, Ordering::SeqCst},
@@ -447,7 +447,7 @@ const GO_PACKAGE_TASK_VARIABLE: VariableName = VariableName::Custom(Cow::Borrowe
 impl ContextProvider for GoContextProvider {
     fn build_context(
         &self,
-        worktree_abs_path: Option<&Path>,
+        variables: &TaskVariables,
         location: &Location,
         cx: &mut gpui::AppContext,
     ) -> Result<TaskVariables> {
@@ -465,7 +465,8 @@ impl ContextProvider for GoContextProvider {
                 // Prefer the relative form `./my-nested-package/is-here` over
                 // absolute path, because it's more readable in the modal, but
                 // the absolute path also works.
-                let package_name = worktree_abs_path
+                let package_name = variables
+                    .get(&VariableName::WorktreeRoot)
                     .and_then(|worktree_abs_path| buffer_dir.strip_prefix(worktree_abs_path).ok())
                     .map(|relative_pkg_dir| {
                         if relative_pkg_dir.as_os_str().is_empty() {

crates/languages/src/python.rs

@@ -1,8 +1,9 @@
 use anyhow::Result;
 use async_trait::async_trait;
-use language::{ContextProviderWithTasks, LanguageServerName, LspAdapter, LspAdapterDelegate};
+use language::{LanguageServerName, LspAdapter, LspAdapterDelegate};
 use lsp::LanguageServerBinary;
 use node_runtime::NodeRuntime;
+use project::ContextProviderWithTasks;
 use std::{
     any::Any,
     ffi::OsString,

crates/languages/src/rust.rs

@@ -328,7 +328,7 @@ const RUST_PACKAGE_TASK_VARIABLE: VariableName =
 impl ContextProvider for RustContextProvider {
     fn build_context(
         &self,
-        _: Option<&Path>,
+        _: &TaskVariables,
         location: &Location,
         cx: &mut gpui::AppContext,
     ) -> Result<TaskVariables> {