DictBuiltins fix setdefault to accept optional default value

- add unittest

Author: cosminbasca

graalpython/com.oracle.graal.python.test/src/tests/test_dict.py

@@ -343,3 +343,34 @@ def test_dictview_mixed_set_operations():
     assert {(1, 1)} == {1: 1}.items()
     assert {1: 1}.items() | {2} == {(1, 1), 2}
     assert {2} | {1: 1}.items() == {(1, 1), 2}
+
+
+def test_setdefault():
+    # dict.setdefault()
+    d = {}
+    none = d.setdefault('key0')
+    assert d.setdefault('key0') is None
+    d.setdefault('key0', [])
+    assert d.setdefault('key0') is None
+    d.setdefault('key', []).append(3)
+    assert d['key'][0] == 3
+    d.setdefault('key', []).append(4)
+    assert len(d['key']) == 2
+    assert_raises(TypeError, d.setdefault)
+
+    class Exc(Exception):
+        pass
+
+    class BadHash(object):
+        fail = False
+
+        def __hash__(self):
+            if self.fail:
+                raise Exc()
+            else:
+                return 42
+
+    x = BadHash()
+    d[x] = 42
+    x.fail = True
+    assert_raises(Exc, d.setdefault, x, [])

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/dict/DictBuiltins.java

@@ -110,7 +110,7 @@ public Object doGeneric(@SuppressWarnings("unused") PDict self, Object[] args, @
     }
 
     // setdefault(key[, default])
-    @Builtin(name = "setdefault", fixedNumOfArguments = 3)
+    @Builtin(name = "setdefault", minNumOfArguments = 2, keywordArguments = {"default"})
     @GenerateNodeFactory
     public abstract static class SetDefaultNode extends PythonBuiltinNode {
         @Child private HashingStorageNodes.ContainsKeyNode containsKeyNode;
@@ -129,6 +129,14 @@ public Object setDefault(PDict dict, Object key, @SuppressWarnings("unused") Obj
             return getItemNode.execute(dict.getDictStorage(), key);
         }
 
+        @Specialization(guards = "!containsKey(dict.getDictStorage(), key)")
+        public Object setDefault(PDict dict, Object key, @SuppressWarnings("unused") PNone defaultValue,
+                        @Cached("create()") HashingStorageNodes.SetItemNode setItemNode) {
+
+            setItemNode.execute(dict, dict.getDictStorage(), key, PNone.NONE);
+            return PNone.NONE;
+        }
+
         @Specialization(guards = "!containsKey(dict.getDictStorage(), key)")
         public Object setDefault(PDict dict, Object key, Object defaultValue,
                         @Cached("create()") HashingStorageNodes.SetItemNode setItemNode) {