change: add an utility function to find multiple processors

add an utility function .processors.finds_with_pred to find multiple
processors matches with predicate, and its test cases.

anyconfig/processors.py

@@ -45,6 +45,16 @@ def load_plugins(pgroup, safe=True):
     return list(_load_plugins_itr(pgroup, safe=safe))
 
 
+def finds_with_pred(predicate, prs):
+    """
+    :param predicate: any callable to filter results
+    :param prs: A list of :class:`anyconfig.models.processor.Processor` classes
+    :return: A list of appropriate processor classes or []
+    """
+    return sorted((p for p in prs if predicate(p)),
+                  key=operator.methodcaller("priority"), reverse=True)
+
+
 def find_with_pred(predicate, prs):
     """
     :param predicate: any callable to filter results
@@ -75,8 +85,7 @@ def find_with_pred(predicate, prs):
     >>> x = find_with_pred(lambda p: p.type() == "x", prs)
     >>> assert x is None
     """
-    _prs = sorted((p for p in prs if predicate(p)),
-                  key=operator.methodcaller("priority"), reverse=True)
+    _prs = finds_with_pred(predicate, prs)
     if _prs:
         return _prs[0]  # Found.
 

tests/processors.py

@@ -20,16 +20,17 @@ class A(anyconfig.models.processor.Processor):
 
 
 class A2(A):
-    pass
+    _priority = 20  # Higher priority than A.
 
 
 class A3(A):
-    _priority = 99  # Higher priority than A.
+    _priority = 99  # Higher priority than A and A2.
 
 
 class B(anyconfig.models.processor.Processor):
     _type = "yaml"
     _extensions = ['yaml', 'yml']
+    _priority = 99  # Higher priority than C.
 
 
 class C(anyconfig.models.processor.Processor):
@@ -50,6 +51,25 @@ def test_10_eq(self):
         self.assertNotEqual(a1, a22)
 
 
+class Test_20_finds_functions(unittest.TestCase):
+
+    def test_10_finds_with_pred__type(self):
+        def _finds_by_type(typ):
+            return TT.finds_with_pred(lambda p: p.type() == typ, PRS)
+
+        self.assertEqual(_finds_by_type("json"), [A3, A2, A])
+        self.assertEqual(_finds_by_type("yaml"), [B, C])
+        self.assertEqual(_finds_by_type("undefined"), [])
+
+    def test_20_finds_with_pred__ext(self):
+        def _finds_with_pred__ext(ext):
+            return TT.finds_with_pred(lambda p: ext in p.extensions(), PRS)
+
+        self.assertEqual(_finds_with_pred__ext("js"), [A3, A2, A])
+        self.assertEqual(_finds_with_pred__ext("yml"), [B, C])
+        self.assertEqual(_finds_with_pred__ext("xyz"), [])
+
+
 class Test_30_find_functions(unittest.TestCase):
 
     def assertInstance(self, obj, cls):