Add tests for maps with dots

This adds some unit tests for config maps with dots in the key values.
We check for maps with keys which have overlapping names. There are
however still issues with nested maps which create overlapping flattened
names, as well as nested lists with dots in the key.

terraform/resource_test.go

@@ -88,6 +88,100 @@ func TestResourceConfigGet(t *testing.T) {
 			Key:   "foo.5",
 			Value: nil,
 		},
+
+		// get from map
+		{
+			Config: map[string]interface{}{
+				"mapname": []map[string]interface{}{
+					map[string]interface{}{"key": 1},
+				},
+			},
+			Key:   "mapname.0.key",
+			Value: 1,
+		},
+
+		// get from map with dot in key
+		{
+			Config: map[string]interface{}{
+				"mapname": []map[string]interface{}{
+					map[string]interface{}{"key.name": 1},
+				},
+			},
+			Key:   "mapname.0.key.name",
+			Value: 1,
+		},
+
+		// get from map with overlapping key names
+		{
+			Config: map[string]interface{}{
+				"mapname": []map[string]interface{}{
+					map[string]interface{}{
+						"key.name":   1,
+						"key.name.2": 2,
+					},
+				},
+			},
+			Key:   "mapname.0.key.name.2",
+			Value: 2,
+		},
+		{
+			Config: map[string]interface{}{
+				"mapname": []map[string]interface{}{
+					map[string]interface{}{
+						"key.name":     1,
+						"key.name.foo": 2,
+					},
+				},
+			},
+			Key:   "mapname.0.key.name",
+			Value: 1,
+		},
+		{
+			Config: map[string]interface{}{
+				"mapname": []map[string]interface{}{
+					map[string]interface{}{
+						"listkey": []map[string]interface{}{
+							{"key": 3},
+						},
+					},
+				},
+			},
+			Key:   "mapname.0.listkey.0.key",
+			Value: 3,
+		},
+		// FIXME: this is ambiguous, and matches the nested map
+		//        leaving here to catch this behaviour if it changes.
+		{
+			Config: map[string]interface{}{
+				"mapname": []map[string]interface{}{
+					map[string]interface{}{
+						"key.name":   1,
+						"key.name.0": 2,
+						"key":        map[string]interface{}{"name": 3},
+					},
+				},
+			},
+			Key:   "mapname.0.key.name",
+			Value: 3,
+		},
+		/*
+			// TODO: can't access this nested list at all.
+			// FIXME: key with name matching substring of nested list can panic
+			{
+				Config: map[string]interface{}{
+					"mapname": []map[string]interface{}{
+						map[string]interface{}{
+							"key.name": []map[string]interface{}{
+								{"subkey": 1},
+							},
+							"key": 3,
+						},
+					},
+				},
+				Key:   "mapname.0.key.name.0.subkey",
+				Value: 3,
+			},
+		*/
 	}
 
 	for i, tc := range cases {