Add module_path() function (#3270)

Author: casey

README.md

@@ -1999,11 +1999,13 @@ called from within an import or submodule.
 
 #### Module and Module Directory
 
-- `module_file()` - Retrieves the path of the current module file.
+- `module_file()` - Returns the path of the current module file.
 
-- `module_directory()` - Retrieves the path of the parent directory of the
+- `module_directory()` - Returns the path of the parent directory of the
   current module file.
 
+- `module_path()` - Returns the `::`-separated path to the current module.
+
 `module_file()` and `module_directory()` behave the same as `justfile()` and
 `justfile_directory()` in the root `justfile`, but will return the path and
 directory, respectively, of the current `mod` source file when called from

src/function.rs

@@ -76,6 +76,7 @@ pub(crate) fn get(name: &str) -> Option<Function> {
     "lowercase" => Unary(lowercase),
     "module_directory" => Nullary(module_directory),
     "module_file" => Nullary(module_file),
+    "module_path" => Nullary(module_path),
     "num_cpus" => Nullary(num_cpus),
     "os" => Nullary(os),
     "os_family" => Nullary(os_family),
@@ -463,6 +464,10 @@ fn module_file(context: Context) -> FunctionResult {
   })
 }
 
+fn module_path(context: Context) -> FunctionResult {
+  Ok(context.execution_context.module.modulepath.to_string())
+}
+
 fn num_cpus(_context: Context) -> FunctionResult {
   let num = num_cpus::get();
   Ok(num.to_string())

tests/functions.rs

@@ -1508,3 +1508,23 @@ fn shell_with_powershell() {
     .stdout("bar\r\n")
     .success();
 }
+
+#[test]
+fn module_path() {
+  Test::new()
+    .justfile("foo := module_path()")
+    .args(["--evaluate", "foo"])
+    .stdout("")
+    .success();
+}
+
+#[test]
+fn module_path_in_submodule() {
+  Test::new()
+    .write("foo.just", "mod bar")
+    .write("bar.just", "baz := module_path()")
+    .justfile("mod foo")
+    .args(["--evaluate", "foo::bar::baz"])
+    .stdout("foo::bar")
+    .success();
+}