Add child_packages

src/import_graph/graph.rs

@@ -98,6 +98,20 @@ impl ImportGraph {
         Ok(packages)
     }
 
+    pub fn child_packages(&self, package: &str) -> Result<HashSet<&str>> {
+        let package: &Package = match self.borrow_packages_by_pypath().get(package) {
+            Some(package) => package,
+            None => {
+                return Err(Error::PackageNotFound(package.to_string()))?;
+            }
+        };
+        let mut packages = HashSet::new();
+        for child in package.children.iter() {
+            packages.insert(child.pypath.as_str());
+        }
+        Ok(packages)
+    }
+
     pub fn child_modules(&self, package: &str) -> Result<HashSet<&str>> {
         let package: &Package = match self.borrow_packages_by_pypath().get(package) {
             Some(package) => package,

tests/test_import_graph.rs

@@ -104,6 +104,22 @@ fn test_packages_from_modules() {
     );
 }
 
+#[test]
+fn test_child_packages() {
+    let root_package_path = Path::new("./testpackages/somesillypackage");
+    let import_graph = ImportGraphBuilder::new(root_package_path).build().unwrap();
+    assert_eq!(
+        import_graph.child_packages("somesillypackage").unwrap(),
+        hashset! {
+            "somesillypackage.child1",
+            "somesillypackage.child2",
+            "somesillypackage.child3",
+            "somesillypackage.child4",
+            "somesillypackage.child5",
+        },
+    );
+}
+
 #[test]
 fn test_child_modules() {
     let root_package_path = Path::new("./testpackages/somesillypackage");