[3.6] bpo-1612262: IDLE: Class Browser shows nested functions, classes (GH-2573) (#3702)

Original patches for code and tests by Guilherme Polo and
Cheryl Sabella, respectively.

(cherry picked from commit 058de113)

Lib/idlelib/_pyclbr.py

+# A private copy of 3.7.0a1 pyclbr for use by idlelib.browser
+"""Parse a Python module and describe its classes and functions.
+
+Parse enough of a Python file to recognize imports and class and
+function definitions, and to find out the superclasses of a class.
+
+The interface consists of a single function:
+    readmodule_ex(module, path=None)
+where module is the name of a Python module, and path is an optional
+list of directories where the module is to be searched.  If present,
+path is prepended to the system search path sys.path.  The return value
+is a dictionary.  The keys of the dictionary are the names of the
+classes and functions defined in the module (including classes that are
+defined via the from XXX import YYY construct).  The values are
+instances of classes Class and Function.  One special key/value pair is
+present for packages: the key '__path__' has a list as its value which
+contains the package search path.
+
+Classes and Functions have a common superclass: _Object.  Every instance
+has the following attributes:
+    module  -- name of the module;
+    name    -- name of the object;
+    file    -- file in which the object is defined;
+    lineno  -- line in the file where the object's definition starts;
+    parent  -- parent of this object, if any;
+    children -- nested objects contained in this object.
+The 'children' attribute is a dictionary mapping names to objects.
+
+Instances of Function describe functions with the attributes from _Object.
+
+Instances of Class describe classes with the attributes from _Object,
+plus the following:
+    super   -- list of super classes (Class instances if possible);
+    methods -- mapping of method names to beginning line numbers.
+If the name of a super class is not recognized, the corresponding
+entry in the list of super classes is not a class instance but a
+string giving the name of the super class.  Since import statements
+are recognized and imported modules are scanned as well, this
+shouldn't happen often.
+"""
+
+import io
+import sys
+import importlib.util
+import tokenize
+from token import NAME, DEDENT, OP
+
+__all__ = ["readmodule", "readmodule_ex", "Class", "Function"]
+
+_modules = {}  # Initialize cache of modules we've seen.
+
+
+class _Object:
+    "Informaton about Python class or function."
+    def __init__(self, module, name, file, lineno, parent):
+        self.module = module
+        self.name = name
+        self.file = file
+        self.lineno = lineno
+        self.parent = parent
+        self.children = {}
+
+    def _addchild(self, name, obj):
+        self.children[name] = obj
+
+
+class Function(_Object):
+    "Information about a Python function, including methods."
+    def __init__(self, module, name, file, lineno, parent=None):
+        _Object.__init__(self, module, name, file, lineno, parent)
+
+
+class Class(_Object):
+    "Information about a Python class."
+    def __init__(self, module, name, super, file, lineno, parent=None):
+        _Object.__init__(self, module, name, file, lineno, parent)
+        self.super = [] if super is None else super
+        self.methods = {}
+
+    def _addmethod(self, name, lineno):
+        self.methods[name] = lineno
+
+
+def _nest_function(ob, func_name, lineno):
+    "Return a Function after nesting within ob."
+    newfunc = Function(ob.module, func_name, ob.file, lineno, ob)
+    ob._addchild(func_name, newfunc)
+    if isinstance(ob, Class):
+        ob._addmethod(func_name, lineno)
+    return newfunc
+
+def _nest_class(ob, class_name, lineno, super=None):
+    "Return a Class after nesting within ob."
+    newclass = Class(ob.module, class_name, super, ob.file, lineno, ob)
+    ob._addchild(class_name, newclass)
+    return newclass
+
+def readmodule(module, path=None):
+    """Return Class objects for the top-level classes in module.
+
+    This is the original interface, before Functions were added.
+    """
+
+    res = {}
+    for key, value in _readmodule(module, path or []).items():
+        if isinstance(value, Class):
+            res[key] = value
+    return res
+
+def readmodule_ex(module, path=None):
+    """Return a dictionary with all functions and classes in module.
+
+    Search for module in PATH + sys.path.
+    If possible, include imported superclasses.
+    Do this by reading source, without importing (and executing) it.
+    """
+    return _readmodule(module, path or [])
+
+def _readmodule(module, path, inpackage=None):
+    """Do the hard work for readmodule[_ex].
+
+    If inpackage is given, it must be the dotted name of the package in
+    which we are searching for a submodule, and then PATH must be the
+    package search path; otherwise, we are searching for a top-level
+    module, and path is combined with sys.path.
+    """
+    # Compute the full module name (prepending inpackage if set).
+    if inpackage is not None:
+        fullmodule = "%s.%s" % (inpackage, module)
+    else:
+        fullmodule = module
+
+    # Check in the cache.
+    if fullmodule in _modules:
+        return _modules[fullmodule]
+
+    # Initialize the dict for this module's contents.
+    tree = {}
+
+    # Check if it is a built-in module; we don't do much for these.
+    if module in sys.builtin_module_names and inpackage is None:
+        _modules[module] = tree
+        return tree
+
+    # Check for a dotted module name.
+    i = module.rfind('.')
+    if i >= 0:
+        package = module[:i]
+        submodule = module[i+1:]
+        parent = _readmodule(package, path, inpackage)
+        if inpackage is not None:
+            package = "%s.%s" % (inpackage, package)
+        if not '__path__' in parent:
+            raise ImportError('No package named {}'.format(package))
+        return _readmodule(submodule, parent['__path__'], package)
+
+    # Search the path for the module.
+    f = None
+    if inpackage is not None:
+        search_path = path
+    else:
+        search_path = path + sys.path
+    spec = importlib.util._find_spec_from_path(fullmodule, search_path)
+    _modules[fullmodule] = tree
+    # Is module a package?
+    if spec.submodule_search_locations is not None:
+        tree['__path__'] = spec.submodule_search_locations
+    try:
+        source = spec.loader.get_source(fullmodule)
+        if source is None:
+            return tree
+    except (AttributeError, ImportError):
+        # If module is not Python source, we cannot do anything.
+        return tree
+
+    fname = spec.loader.get_filename(fullmodule)
+    return _create_tree(fullmodule, path, fname, source, tree, inpackage)
+
+
+def _create_tree(fullmodule, path, fname, source, tree, inpackage):
+    """Return the tree for a particular module.
+
+    fullmodule (full module name), inpackage+module, becomes o.module.
+    path is passed to recursive calls of _readmodule.
+    fname becomes o.file.
+    source is tokenized.  Imports cause recursive calls to _readmodule.
+    tree is {} or {'__path__': <submodule search locations>}.
+    inpackage, None or string, is passed to recursive calls of _readmodule.
+
+    The effect of recursive calls is mutation of global _modules.
+    """
+    f = io.StringIO(source)
+
+    stack = [] # Initialize stack of (class, indent) pairs.
+
+    g = tokenize.generate_tokens(f.readline)
+    try:
+        for tokentype, token, start, _end, _line in g:
+            if tokentype == DEDENT:
+                lineno, thisindent = start
+                # Close previous nested classes and defs.
+                while stack and stack[-1][1] >= thisindent:
+                    del stack[-1]
+            elif token == 'def':
+                lineno, thisindent = start
+                # Close previous nested classes and defs.
+                while stack and stack[-1][1] >= thisindent:
+                    del stack[-1]
+                tokentype, func_name, start = next(g)[0:3]
+                if tokentype != NAME:
+                    continue  # Skip def with syntax error.
+                cur_func = None
+                if stack:
+                    cur_obj = stack[-1][0]
+                    cur_func = _nest_function(cur_obj, func_name, lineno)
+                else:
+                    # It is just a function.
+                    cur_func = Function(fullmodule, func_name, fname, lineno)
+                    tree[func_name] = cur_func
+                stack.append((cur_func, thisindent))
+            elif token == 'class':
+                lineno, thisindent = start
+                # Close previous nested classes and defs.
+                while stack and stack[-1][1] >= thisindent:
+                    del stack[-1]
+                tokentype, class_name, start = next(g)[0:3]
+                if tokentype != NAME:
+                    continue # Skip class with syntax error.
+                # Parse what follows the class name.
+                tokentype, token, start = next(g)[0:3]
+                inherit = None
+                if token == '(':
+                    names = [] # Initialize list of superclasses.
+                    level = 1
+                    super = [] # Tokens making up current superclass.
+                    while True:
+                        tokentype, token, start = next(g)[0:3]
+                        if token in (')', ',') and level == 1:
+                            n = "".join(super)
+                            if n in tree:
+                                # We know this super class.
+                                n = tree[n]
+                            else:
+                                c = n.split('.')
+                                if len(c) > 1:
+                                    # Super class form is module.class:
+                                    # look in module for class.
+                                    m = c[-2]
+                                    c = c[-1]
+                                    if m in _modules:
+                                        d = _modules[m]
+                                        if c in d:
+                                            n = d[c]
+                            names.append(n)
+                            super = []
+                        if token == '(':
+                            level += 1
+                        elif token == ')':
+                            level -= 1
+                            if level == 0:
+                                break
+                        elif token == ',' and level == 1:
+                            pass
+                        # Only use NAME and OP (== dot) tokens for type name.
+                        elif tokentype in (NAME, OP) and level == 1:
+                            super.append(token)
+                        # Expressions in the base list are not supported.
+                    inherit = names
+                if stack:
+                    cur_obj = stack[-1][0]
+                    cur_class = _nest_class(
+                            cur_obj, class_name, lineno, inherit)
+                else:
+                    cur_class = Class(fullmodule, class_name, inherit,
+                                      fname, lineno)
+                    tree[class_name] = cur_class
+                stack.append((cur_class, thisindent))
+            elif token == 'import' and start[1] == 0:
+                modules = _getnamelist(g)
+                for mod, _mod2 in modules:
+                    try:
+                        # Recursively read the imported module.
+                        if inpackage is None:
+                            _readmodule(mod, path)
+                        else:
+                            try:
+                                _readmodule(mod, path, inpackage)
+                            except ImportError:
+                                _readmodule(mod, [])
+                    except:
+                        # If we can't find or parse the imported module,
+                        # too bad -- don't die here.
+                        pass
+            elif token == 'from' and start[1] == 0:
+                mod, token = _getname(g)
+                if not mod or token != "import":
+                    continue
+                names = _getnamelist(g)
+                try:
+                    # Recursively read the imported module.
+                    d = _readmodule(mod, path, inpackage)
+                except:
+                    # If we can't find or parse the imported module,
+                    # too bad -- don't die here.
+                    continue
+                # Add any classes that were defined in the imported module
+                # to our name space if they were mentioned in the list.
+                for n, n2 in names:
+                    if n in d:
+                        tree[n2 or n] = d[n]
+                    elif n == '*':
+                        # Don't add names that start with _.
+                        for n in d:
+                            if n[0] != '_':
+                                tree[n] = d[n]
+    except StopIteration:
+        pass
+
+    f.close()
+    return tree
+
+
+def _getnamelist(g):
+    """Return list of (dotted-name, as-name or None) tuples for token source g.
+
+    An as-name is the name that follows 'as' in an as clause.
+    """
+    names = []
+    while True:
+        name, token = _getname(g)
+        if not name:
+            break
+        if token == 'as':
+            name2, token = _getname(g)
+        else:
+            name2 = None
+        names.append((name, name2))
+        while token != "," and "\n" not in token:
+            token = next(g)[1]
+        if token != ",":
+            break
+    return names
+
+
+def _getname(g):
+    "Return (dotted-name or None, next-token) tuple for token source g."
+    parts = []
+    tokentype, token = next(g)[0:2]
+    if tokentype != NAME and token != '*':
+        return (None, token)
+    parts.append(token)
+    while True:
+        tokentype, token = next(g)[0:2]
+        if token != '.':
+            break
+        tokentype, token = next(g)[0:2]
+        if tokentype != NAME:
+            break
+        parts.append(token)
+    return (".".join(parts), token)
+
+
+def _main():
+    "Print module output (default this file) for quick visual check."
+    import os
+    try:
+        mod = sys.argv[1]
+    except:
+        mod = __file__
+    if os.path.exists(mod):
+        path = [os.path.dirname(mod)]
+        mod = os.path.basename(mod)
+        if mod.lower().endswith(".py"):
+            mod = mod[:-3]
+    else:
+        path = []
+    tree = readmodule_ex(mod, path)
+    lineno_key = lambda a: getattr(a, 'lineno', 0)
+    objs = sorted(tree.values(), key=lineno_key, reverse=True)
+    indent_level = 2
+    while objs:
+        obj = objs.pop()
+        if isinstance(obj, list):
+            # Value is a __path__ key.
+            continue
+        if not hasattr(obj, 'indent'):
+            obj.indent = 0
+
+        if isinstance(obj, _Object):
+            new_objs = sorted(obj.children.values(),
+                              key=lineno_key, reverse=True)
+            for ob in new_objs:
+                ob.indent = obj.indent + indent_level
+            objs.extend(new_objs)
+        if isinstance(obj, Class):
+            print("{}class {} {} {}"
+                  .format(' ' * obj.indent, obj.name, obj.super, obj.lineno))
+        elif isinstance(obj, Function):
+            print("{}def {} {}".format(' ' * obj.indent, obj.name, obj.lineno))
+
+if __name__ == "__main__":
+    _main()

Lib/idlelib/browser.py

@@ -11,7 +11,7 @@ XXX TO DO:
 """
 
 import os
-import pyclbr
+from idlelib import _pyclbr as pyclbr
 import sys
 
 from idlelib.config import idleConf
@@ -19,14 +19,49 @@ from idlelib import pyshell
 from idlelib.tree import TreeNode, TreeItem, ScrolledCanvas
 from idlelib.windows import ListedToplevel
 
+
 file_open = None  # Method...Item and Class...Item use this.
 # Normally pyshell.flist.open, but there is no pyshell.flist for htest.
 
+
+def transform_children(child_dict, modname=None):
+    """Transform a child dictionary to an ordered sequence of objects.
+
+    The dictionary maps names to pyclbr information objects.
+    Filter out imported objects.
+    Augment class names with bases.
+    Sort objects by line number.
+
+    The current tree only calls this once per child_dic as it saves
+    TreeItems once created.  A future tree and tests might violate this,
+    so a check prevents multiple in-place augmentations.
+    """
+    obs = []  # Use list since values should already be sorted.
+    for key, obj in child_dict.items():
+        if modname is None or obj.module == modname:
+            if hasattr(obj, 'super') and obj.super and obj.name == key:
+                # If obj.name != key, it has already been suffixed.
+                supers = []
+                for sup in obj.super:
+                    if type(sup) is type(''):
+                        sname = sup
+                    else:
+                        sname = sup.name
+                        if sup.module != obj.module:
+                            sname = f'{sup.module}.{sname}'
+                    supers.append(sname)
+                obj.name += '({})'.format(', '.join(supers))
+            obs.append(obj)
+    return sorted(obs, key=lambda o: o.lineno)
+
+
 class ClassBrowser:
     """Browse module classes and functions in IDLE.
     """
+    # This class is the base class for pathbrowser.PathBrowser.
+    # Init and close are inherited, other methods are overriden.
 
-    def __init__(self, flist, name, path, _htest=False):
+    def __init__(self, flist, name, path, _htest=False, _utest=False):
         # XXX This API should change, if the file doesn't end in ".py"
         # XXX the code here is bogus!
         """Create a window for browsing a module's structure.
@@ -47,11 +82,12 @@ class ClassBrowser:
                 the tree and subsequently in the children.
         """
         global file_open
-        if not _htest:
+        if not (_htest or _utest):
             file_open = pyshell.flist.open
         self.name = name
         self.file = os.path.join(path[0], self.name + ".py")
         self._htest = _htest
+        self._utest = _utest
         self.init(flist)
 
     def close(self, event=None):
@@ -80,8 +116,9 @@ class ClassBrowser:
         sc.frame.pack(expand=1, fill="both")
         item = self.rootnode()
         self.node = node = TreeNode(sc.canvas, None, item)
-        node.update()
-        node.expand()
+        if not self._utest:
+            node.update()
+            node.expand()
 
     def settitle(self):
         "Set the window title."
@@ -92,6 +129,7 @@ class ClassBrowser:
         "Return a ModuleBrowserTreeItem as the root of the tree."
         return ModuleBrowserTreeItem(self.file)
 
+
 class ModuleBrowserTreeItem(TreeItem):
     """Browser tree for Python module.
 
@@ -115,16 +153,8 @@ class ModuleBrowserTreeItem(TreeItem):
         return "python"
 
     def GetSubList(self):
-        """Return the list of ClassBrowserTreeItem items.
-
-        Each item returned from listclasses is the first level of
-        classes/functions within the module.
-        """
-        sublist = []
-        for name in self.listclasses():
-            item = ClassBrowserTreeItem(name, self.classes, self.file)
-            sublist.append(item)
-        return sublist
+        "Return ChildBrowserTreeItems for children."
+        return [ChildBrowserTreeItem(obj) for obj in self.listchildren()]
 
     def OnDoubleClick(self):
         "Open a module in an editor window when double clicked."
@@ -132,89 +162,44 @@ class ModuleBrowserTreeItem(TreeItem):
             return
         if not os.path.exists(self.file):
             return
-        pyshell.flist.open(self.file)
+        file_open(self.file)
 
     def IsExpandable(self):
         "Return True if Python (.py) file."
         return os.path.normcase(self.file[-3:]) == ".py"
 
-    def listclasses(self):
-        """Return list of classes and functions in the module.
-
-        The dictionary output from pyclbr is re-written as a
-        list of tuples in the form (lineno, name) and
-        then sorted so that the classes and functions are
-        processed in line number order.  The returned list only
-        contains the name and not the line number.  An instance
-        variable self.classes contains the pyclbr dictionary values,
-        which are instances of Class and Function.
-        """
+    def listchildren(self):
+        "Return sequenced classes and functions in the module."
         dir, file = os.path.split(self.file)
         name, ext = os.path.splitext(file)
         if os.path.normcase(ext) != ".py":
             return []
         try:
-            dict = pyclbr.readmodule_ex(name, [dir] + sys.path)
+            tree = pyclbr.readmodule_ex(name, [dir] + sys.path)
         except ImportError:
             return []
-        items = []
-        self.classes = {}
-        for key, cl in dict.items():
-            if cl.module == name:
-                s = key
-                if hasattr(cl, 'super') and cl.super:
-                    supers = []
-                    for sup in cl.super:
-                        if type(sup) is type(''):
-                            sname = sup
-                        else:
-                            sname = sup.name
-                            if sup.module != cl.module:
-                                sname = "%s.%s" % (sup.module, sname)
-                        supers.append(sname)
-                    s = s + "(%s)" % ", ".join(supers)
-                items.append((cl.lineno, s))
-                self.classes[s] = cl
-        items.sort()
-        list = []
-        for item, s in items:
-            list.append(s)
-        return list
-
-class ClassBrowserTreeItem(TreeItem):
-    """Browser tree for classes within a module.
+        return transform_children(tree, name)
 
-    Uses TreeItem as the basis for the structure of the tree.
-    """
 
-    def __init__(self, name, classes, file):
-        """Create a TreeItem for the class/function.
+class ChildBrowserTreeItem(TreeItem):
+    """Browser tree for child nodes within the module.
 
-        Args:
-            name: Name of the class/function.
-            classes: Dictonary of Class/Function instances from pyclbr.
-            file: Full path and module name.
+    Uses TreeItem as the basis for the structure of the tree.
+    """
 
-        Instance variables:
-            self.cl: Class/Function instance for the class/function name.
-            self.isfunction: True if self.cl is a Function.
-        """
-        self.name = name
-        # XXX - Does classes need to be an instance variable?
-        self.classes = classes
-        self.file = file
-        try:
-            self.cl = self.classes[self.name]
-        except (IndexError, KeyError):
-            self.cl = None
-        self.isfunction = isinstance(self.cl, pyclbr.Function)
+    def __init__(self, obj):
+        "Create a TreeItem for a pyclbr class/function object."
+        self.obj = obj
+        self.name = obj.name
+        self.isfunction = isinstance(obj, pyclbr.Function)
 
     def GetText(self):
         "Return the name of the function/class to display."
+        name = self.name
         if self.isfunction:
-            return "def " + self.name + "(...)"
+            return "def " + name + "(...)"
         else:
-            return "class " + self.name
+            return "class " + name
 
     def GetIconName(self):
         "Return the name of the icon to display."
@@ -224,95 +209,34 @@ class ClassBrowserTreeItem(TreeItem):
             return "folder"
 
     def IsExpandable(self):
-        "Return True if this class has methods."
-        if self.cl:
-            try:
-                return not not self.cl.methods
-            except AttributeError:
-                return False
-        return None
+        "Return True if self.obj has nested objects."
+        return self.obj.children != {}
 
     def GetSubList(self):
-        """Return Class methods as a list of MethodBrowserTreeItem items.
-
-        Each item is a method within the class.
-        """
-        if not self.cl:
-            return []
-        sublist = []
-        for name in self.listmethods():
-            item = MethodBrowserTreeItem(name, self.cl, self.file)
-            sublist.append(item)
-        return sublist
+        "Return ChildBrowserTreeItems for children."
+        return [ChildBrowserTreeItem(obj)
+                for obj in transform_children(self.obj.children)]
 
     def OnDoubleClick(self):
-        "Open module with file_open and position to lineno, if it exists."
-        if not os.path.exists(self.file):
-            return
-        edit = file_open(self.file)
-        if hasattr(self.cl, 'lineno'):
-            lineno = self.cl.lineno
-            edit.gotoline(lineno)
-
-    def listmethods(self):
-        "Return list of methods within a class sorted by lineno."
-        if not self.cl:
-            return []
-        items = []
-        for name, lineno in self.cl.methods.items():
-            items.append((lineno, name))
-        items.sort()
-        list = []
-        for item, name in items:
-            list.append(name)
-        return list
-
-class MethodBrowserTreeItem(TreeItem):
-    """Browser tree for methods within a class.
-
-    Uses TreeItem as the basis for the structure of the tree.
-    """
-
-    def __init__(self, name, cl, file):
-        """Create a TreeItem for the methods.
-
-        Args:
-            name: Name of the class/function.
-            cl: pyclbr.Class instance for name.
-            file: Full path and module name.
-        """
-        self.name = name
-        self.cl = cl
-        self.file = file
-
-    def GetText(self):
-        "Return the method name to display."
-        return "def " + self.name + "(...)"
-
-    def GetIconName(self):
-        "Return the name of the icon to display."
-        return "python"
-
-    def IsExpandable(self):
-        "Return False as there are no tree items after methods."
-        return False
+        "Open module with file_open and position to lineno."
+        try:
+            edit = file_open(self.obj.file)
+            edit.gotoline(self.obj.lineno)
+        except (OSError, AttributeError):
+            pass
 
-    def OnDoubleClick(self):
-        "Open module with file_open and position at the method start."
-        if not os.path.exists(self.file):
-            return
-        edit = file_open(self.file)
-        edit.gotoline(self.cl.methods[self.name])
 
 def _class_browser(parent): # htest #
     try:
+        file = sys.argv[1]  # If pass file on command line
+        # If this succeeds, unittest will fail.
+    except IndexError:
         file = __file__
-    except NameError:
-        file = sys.argv[0]
-        if sys.argv[1:]:
-            file = sys.argv[1]
-        else:
-            file = sys.argv[0]
+        # Add objects for htest
+        class Nested_in_func(TreeNode):
+            def nested_in_class(): pass
+        def closure():
+            class Nested_in_closure: pass
     dir, file = os.path.split(file)
     name = os.path.splitext(file)[0]
     flist = pyshell.PyShellFileList(parent)
@@ -321,5 +245,7 @@ def _class_browser(parent): # htest #
     ClassBrowser(flist, name, [dir], _htest=True)
 
 if __name__ == "__main__":
+    from unittest import main
+    main('idlelib.idle_test.test_browser', verbosity=2, exit=False)
     from idlelib.idle_test.htest import run
     run(_class_browser)

Lib/idlelib/idle_test/test_browser.py

+""" Test idlelib.browser.
+
+Coverage: 88%
+(Higher, because should exclude 3 lines that .coveragerc won't exclude.)
+"""
+
+import os.path
+import unittest
+from idlelib import _pyclbr as pyclbr
+
+from idlelib import browser, filelist
+from idlelib.tree import TreeNode
+from test.support import requires
+from unittest import mock
+from tkinter import Tk
+from idlelib.idle_test.mock_idle import Func
+from collections import deque
+
+
+class ClassBrowserTest(unittest.TestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        requires('gui')
+        cls.root = Tk()
+        cls.root.withdraw()
+        cls.flist = filelist.FileList(cls.root)
+        cls.file = __file__
+        cls.path = os.path.dirname(cls.file)
+        cls.module = os.path.basename(cls.file).rstrip('.py')
+        cls.cb = browser.ClassBrowser(cls.flist, cls.module, [cls.path], _utest=True)
+
+    @classmethod
+    def tearDownClass(cls):
+        cls.cb.close()
+        cls.root.destroy()
+        del cls.root, cls.flist, cls.cb
+
+    def test_init(self):
+        cb = self.cb
+        eq = self.assertEqual
+        eq(cb.name, self.module)
+        eq(cb.file, self.file)
+        eq(cb.flist, self.flist)
+        eq(pyclbr._modules, {})
+        self.assertIsInstance(cb.node, TreeNode)
+
+    def test_settitle(self):
+        cb = self.cb
+        self.assertIn(self.module, cb.top.title())
+        self.assertEqual(cb.top.iconname(), 'Class Browser')
+
+    def test_rootnode(self):
+        cb = self.cb
+        rn = cb.rootnode()
+        self.assertIsInstance(rn, browser.ModuleBrowserTreeItem)
+
+    def test_close(self):
+        cb = self.cb
+        cb.top.destroy = Func()
+        cb.node.destroy = Func()
+        cb.close()
+        self.assertTrue(cb.top.destroy.called)
+        self.assertTrue(cb.node.destroy.called)
+        del cb.top.destroy, cb.node.destroy
+
+
+# Same nested tree creation as in test_pyclbr.py except for super on C0.
+mb = pyclbr
+module, fname = 'test', 'test.py'
+f0 = mb.Function(module, 'f0', fname, 1)
+f1 = mb._nest_function(f0, 'f1', 2)
+f2 = mb._nest_function(f1, 'f2', 3)
+c1 = mb._nest_class(f0, 'c1', 5)
+C0 = mb.Class(module, 'C0', ['base'], fname, 6)
+F1 = mb._nest_function(C0, 'F1', 8)
+C1 = mb._nest_class(C0, 'C1', 11, [''])
+C2 = mb._nest_class(C1, 'C2', 12)
+F3 = mb._nest_function(C2, 'F3', 14)
+mock_pyclbr_tree = {'f0': f0, 'C0': C0}
+
+# transform_children(mock_pyclbr_tree, 'test') mutates C0.name.
+
+class TransformChildrenTest(unittest.TestCase):
+
+    def test_transform_children(self):
+        eq = self.assertEqual
+        # Parameter matches tree module.
+        tcl = list(browser.transform_children(mock_pyclbr_tree, 'test'))
+        eq(tcl[0], f0)
+        eq(tcl[1], C0)
+        eq(tcl[1].name, 'C0(base)')
+        # Check that second call does not add second '(base)' suffix.
+        tcl = list(browser.transform_children(mock_pyclbr_tree, 'test'))
+        eq(tcl[1].name, 'C0(base)')
+        # Nothing to traverse if parameter name isn't same as tree module.
+        tn = browser.transform_children(mock_pyclbr_tree, 'different name')
+        self.assertEqual(list(tn), [])
+        # No name parameter.
+        tn = browser.transform_children({'f1': f1, 'c1': c1})
+        self.assertEqual(list(tn), [f1, c1])
+
+
+class ModuleBrowserTreeItemTest(unittest.TestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        cls.mbt = browser.ModuleBrowserTreeItem(fname)
+
+    def test_init(self):
+        self.assertEqual(self.mbt.file, fname)
+
+    def test_gettext(self):
+        self.assertEqual(self.mbt.GetText(), fname)
+
+    def test_geticonname(self):
+        self.assertEqual(self.mbt.GetIconName(), 'python')
+
+    def test_isexpandable(self):
+        self.assertTrue(self.mbt.IsExpandable())
+
+    def test_listchildren(self):
+        save_rex = browser.pyclbr.readmodule_ex
+        save_tc = browser.transform_children
+        browser.pyclbr.readmodule_ex = Func(result=mock_pyclbr_tree)
+        browser.transform_children = Func(result=[f0, C0])
+        try:
+            self.assertEqual(self.mbt.listchildren(), [f0, C0])
+        finally:
+            browser.pyclbr.readmodule_ex = save_rex
+            browser.transform_children = save_tc
+
+    def test_getsublist(self):
+        mbt = self.mbt
+        mbt.listchildren = Func(result=[f0, C0])
+        sub0, sub1 = mbt.GetSubList()
+        del mbt.listchildren
+        self.assertIsInstance(sub0, browser.ChildBrowserTreeItem)
+        self.assertIsInstance(sub1, browser.ChildBrowserTreeItem)
+        self.assertEqual(sub0.name, 'f0')
+        self.assertEqual(sub1.name, 'C0')
+
+
+    def test_ondoubleclick(self):
+        mbt = self.mbt
+        fopen = browser.file_open = mock.Mock()
+
+        with mock.patch('os.path.exists', return_value=False):
+            mbt.OnDoubleClick()
+            fopen.assert_not_called()
+
+        with mock.patch('os.path.exists', return_value=True):
+            mbt.OnDoubleClick()
+            fopen.assert_called()
+            fopen.called_with(fname)
+
+        del browser.file_open
+
+
+class ChildBrowserTreeItemTest(unittest.TestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        CBT = browser.ChildBrowserTreeItem
+        cls.cbt_f1 = CBT(f1)
+        cls.cbt_C1 = CBT(C1)
+        cls.cbt_F1 = CBT(F1)
+
+    @classmethod
+    def tearDownClass(cls):
+        del cls.cbt_C1, cls.cbt_f1, cls.cbt_F1
+
+    def test_init(self):
+        eq = self.assertEqual
+        eq(self.cbt_C1.name, 'C1')
+        self.assertFalse(self.cbt_C1.isfunction)
+        eq(self.cbt_f1.name, 'f1')
+        self.assertTrue(self.cbt_f1.isfunction)
+
+    def test_gettext(self):
+        self.assertEqual(self.cbt_C1.GetText(), 'class C1')
+        self.assertEqual(self.cbt_f1.GetText(), 'def f1(...)')
+
+    def test_geticonname(self):
+        self.assertEqual(self.cbt_C1.GetIconName(), 'folder')
+        self.assertEqual(self.cbt_f1.GetIconName(), 'python')
+
+    def test_isexpandable(self):
+        self.assertTrue(self.cbt_C1.IsExpandable())
+        self.assertTrue(self.cbt_f1.IsExpandable())
+        self.assertFalse(self.cbt_F1.IsExpandable())
+
+    def test_getsublist(self):
+        eq = self.assertEqual
+        CBT = browser.ChildBrowserTreeItem
+
+        f1sublist = self.cbt_f1.GetSubList()
+        self.assertIsInstance(f1sublist[0], CBT)
+        eq(len(f1sublist), 1)
+        eq(f1sublist[0].name, 'f2')
+
+        eq(self.cbt_F1.GetSubList(), [])
+
+    def test_ondoubleclick(self):
+        fopen = browser.file_open = mock.Mock()
+        goto = fopen.return_value.gotoline = mock.Mock()
+        self.cbt_F1.OnDoubleClick()
+        fopen.assert_called()
+        goto.assert_called()
+        goto.assert_called_with(self.cbt_F1.obj.lineno)
+        del browser.file_open
+        # Failure test would have to raise OSError or AttributeError.
+
+
+class NestedChildrenTest(unittest.TestCase):
+    "Test that all the nodes in a nested tree are added to the BrowserTree."
+
+    def test_nested(self):
+        queue = deque()
+        actual_names = []
+        # The tree items are processed in breadth first order.
+        # Verify that processing each sublist hits every node and
+        # in the right order.
+        expected_names = ['f0', 'C0',  # This is run before transform test.
+                          'f1', 'c1', 'F1', 'C1()',
+                          'f2', 'C2',
+                          'F3']
+        CBT = browser.ChildBrowserTreeItem
+        queue.extend((CBT(f0), CBT(C0)))
+        while queue:
+            cb = queue.popleft()
+            sublist = cb.GetSubList()
+            queue.extend(sublist)
+            self.assertIn(cb.name, cb.GetText())
+            self.assertIn(cb.GetIconName(), ('python', 'folder'))
+            self.assertIs(cb.IsExpandable(), sublist != [])
+            actual_names.append(cb.name)
+        self.assertEqual(actual_names, expected_names)
+
+
+if __name__ == '__main__':
+    unittest.main(verbosity=2)

Lib/idlelib/pathbrowser.py

@@ -9,11 +9,12 @@ from idlelib.tree import TreeItem
 
 class PathBrowser(ClassBrowser):
 
-    def __init__(self, flist, _htest=False):
+    def __init__(self, flist, _htest=False, _utest=False):
         """
         _htest - bool, change box location when running htest
         """
         self._htest = _htest
+        self._utest = _utest
         self.init(flist)
 
     def settitle(self):

Misc/NEWS.d/next/IDLE/2017-08-14-15-13-50.bpo-1612262.-x_Oyq.rst

+IDLE module browser now shows nested classes and functions.
+Original patches for code and tests by Guilherme Polo and
+Cheryl Sabella, respectively.