Fix Go test task when using Git submodules (#17108)

I have found an error running tests in Golang projects that use
submodules. This PR fixes the issue by accessing the directory before
running the test.

![image](https://github.com/user-attachments/assets/3790a77c-a07c-4467-be69-ee8e22675f7a)
The `commons` in the image is a git submodule in a subfolder inside a
parent folder where the workspace is set.


Release Notes:

- Fixed Go tests not being able to run in case the package (and the
`go.mod`) was in a nested folder. Pre-defined Go tasks have been changed
to now run in the package's directory. That means `go test ./package
-run MyTest` will run in `./package` and execute `go test -run MyTest`.
Also, `go test ./...` will run in the package directory, not at the root
of the Zed project, which is a small breaking change. In case one wants
to run `go test ./...` from the root, one can spawn a manual task that
does this.


![image](https://github.com/user-attachments/assets/b7c66f6a-ca29-421e-9539-737c8f719ae2)

---------

Co-authored-by: Thorsten Ball <mrnugget@gmail.com>

crates/languages/src/go.rs

@@ -505,6 +505,12 @@ impl ContextProvider for GoContextProvider {
         _: Option<Arc<dyn language::File>>,
         _: &AppContext,
     ) -> Option<TaskTemplates> {
+        let package_cwd = if GO_PACKAGE_TASK_VARIABLE.template_value() == "." {
+            None
+        } else {
+            Some("$ZED_DIRNAME".to_string())
+        };
+
         Some(TaskTemplates(vec![
             TaskTemplate {
                 label: format!(
@@ -512,26 +518,23 @@ impl ContextProvider for GoContextProvider {
                     GO_PACKAGE_TASK_VARIABLE.template_value(),
                     VariableName::Symbol.template_value(),
                 ),
-                command: "go".into(),
+                command: format!("go test -run {}", VariableName::Symbol.template_value(),),
-                args: vec![
-                    "test".into(),
-                    GO_PACKAGE_TASK_VARIABLE.template_value(),
-                    "-run".into(),
-                    format!("^{}\\$", VariableName::Symbol.template_value(),),
-                ],
                 tags: vec!["go-test".to_owned()],
+                cwd: package_cwd.clone(),
                 ..TaskTemplate::default()
             },
             TaskTemplate {
                 label: format!("go test {}", GO_PACKAGE_TASK_VARIABLE.template_value()),
                 command: "go".into(),
                 args: vec!["test".into(), GO_PACKAGE_TASK_VARIABLE.template_value()],
+                cwd: package_cwd.clone(),
                 ..TaskTemplate::default()
             },
             TaskTemplate {
                 label: "go test ./...".into(),
                 command: "go".into(),
                 args: vec!["test".into(), "./...".into()],
+                cwd: package_cwd.clone(),
                 ..TaskTemplate::default()
             },
             TaskTemplate {
@@ -544,7 +547,6 @@ impl ContextProvider for GoContextProvider {
                 command: "go".into(),
                 args: vec![
                     "test".into(),
-                    GO_PACKAGE_TASK_VARIABLE.template_value(),
                     "-v".into(),
                     "-run".into(),
                     format!(
@@ -553,6 +555,7 @@ impl ContextProvider for GoContextProvider {
                         GO_SUBTEST_NAME_TASK_VARIABLE.template_value(),
                     ),
                 ],
+                cwd: package_cwd.clone(),
                 tags: vec!["go-subtest".to_owned()],
                 ..TaskTemplate::default()
             },
@@ -571,13 +574,15 @@ impl ContextProvider for GoContextProvider {
                     "-bench".into(),
                     format!("^{}\\$", VariableName::Symbol.template_value()),
                 ],
+                cwd: package_cwd.clone(),
                 tags: vec!["go-benchmark".to_owned()],
                 ..TaskTemplate::default()
             },
             TaskTemplate {
                 label: format!("go run {}", GO_PACKAGE_TASK_VARIABLE.template_value(),),
                 command: "go".into(),
-                args: vec!["run".into(), GO_PACKAGE_TASK_VARIABLE.template_value()],
+                args: vec!["run".into(), ".".into()],
+                cwd: package_cwd.clone(),
                 tags: vec!["go-main".to_owned()],
                 ..TaskTemplate::default()
             },