#267 Add test highlighting a diskcache bug

 * this is a Python pickle bug
 * somehow, some data structures cannot be pickled with HIGHEST_PROTOCOL
 * But they pickle alright with no proptocol set

Signed-off-by: Philippe Ombredanne <pombredanne@nexb.com>

tests/scancode/data/cache/package/package.json

@@ -0,0 +1,96 @@
+{
+  "name": "async",
+  "description": "Higher-order functions and common patterns for asynchronous code",
+  "main": "lib/async.js",
+  "author": {
+    "name": "Caolan McMahon"
+  },
+  "version": "1.2.1",
+  "keywords": [
+    "async",
+    "callback",
+    "utility",
+    "module"
+  ],
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/caolan/async.git"
+  },
+  "bugs": {
+    "url": "https://github.com/caolan/async/issues"
+  },
+  "license": "MIT",
+  "devDependencies": {
+    "benchmark": "github:bestiejs/benchmark.js",
+    "coveralls": "^2.11.2",
+    "jshint": "~2.7.0",
+    "lodash": ">=2.4.1",
+    "mkdirp": "~0.5.1",
+    "nodeunit": ">0.0.0",
+    "nyc": "^2.1.0",
+    "uglify-js": "1.2.x",
+    "yargs": "~3.9.1"
+  },
+  "jam": {
+    "main": "lib/async.js",
+    "include": [
+      "lib/async.js",
+      "README.md",
+      "LICENSE"
+    ],
+    "categories": [
+      "Utilities"
+    ]
+  },
+  "scripts": {
+    "test": "npm run-script lint && nodeunit test/test-async.js",
+    "lint": "jshint lib/*.js test/*.js perf/*.js",
+    "coverage": "nyc npm test && nyc report",
+    "coveralls": "nyc npm test && nyc report --reporter=text-lcov | coveralls"
+  },
+  "spm": {
+    "main": "lib/async.js"
+  },
+  "volo": {
+    "main": "lib/async.js",
+    "ignore": [
+      "**/.*",
+      "node_modules",
+      "bower_components",
+      "test",
+      "tests"
+    ]
+  },
+  "gitHead": "b66e85d1cca8c8056313253f22d18f571e7001d2",
+  "homepage": "https://github.com/caolan/async#readme",
+  "_id": "async@1.2.1",
+  "_shasum": "a4816a17cd5ff516dfa2c7698a453369b9790de0",
+  "_from": "async@*",
+  "_npmVersion": "2.9.0",
+  "_nodeVersion": "2.0.2",
+  "_npmUser": {
+    "name": "aearly",
+    "email": "alexander.early@gmail.com"
+  },
+  "maintainers": [
+    {
+      "name": "caolan",
+      "email": "caolan.mcmahon@gmail.com"
+    },
+    {
+      "name": "beaugunderson",
+      "email": "beau@beaugunderson.com"
+    },
+    {
+      "name": "aearly",
+      "email": "alexander.early@gmail.com"
+    }
+  ],
+  "dist": {
+    "shasum": "a4816a17cd5ff516dfa2c7698a453369b9790de0",
+    "tarball": "http://registry.npmjs.org/async/-/async-1.2.1.tgz"
+  },
+  "directories": {},
+  "_resolved": "https://registry.npmjs.org/async/-/async-1.2.1.tgz",
+  "readme": "ERROR: No README data found!"
+}

tests/scancode/test_cache.py

@@ -0,0 +1,45 @@
+#
+# Copyright (c) 2016 nexB Inc. and others. All rights reserved.
+# http://nexb.com and https://github.com/nexB/scancode-toolkit/
+# The ScanCode software is licensed under the Apache License version 2.0.
+# Data generated with ScanCode require an acknowledgment.
+# ScanCode is a trademark of nexB Inc.
+#
+# You may not use this software except in compliance with the License.
+# You may obtain a copy of the License at: http://apache.org/licenses/LICENSE-2.0
+# Unless required by applicable law or agreed to in writing, software distributed
+# under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+# CONDITIONS OF ANY KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations under the License.
+#
+# When you publish or redistribute any data created with ScanCode or any ScanCode
+# derivative work, you must accompany this data with the following acknowledgment:
+#
+#  Generated with ScanCode and provided on an "AS IS" BASIS, WITHOUT WARRANTIES
+#  OR CONDITIONS OF ANY KIND, either express or implied. No content created from
+#  ScanCode should be considered or used as legal advice. Consult an Attorney
+#  for any legal advice.
+#  ScanCode is a free software code scanning tool from nexB Inc. and others.
+#  Visit https://github.com/nexB/scancode-toolkit/ for support and download.
+
+from __future__ import absolute_import, print_function
+
+import os
+
+from commoncode.testcase import FileBasedTesting
+
+from scancode.cache import ScanCache
+
+
+class TestCache(FileBasedTesting):
+    test_data_dir = os.path.join(os.path.dirname(__file__), 'data')
+
+    def test_can_cache(self):
+        test_file = self.get_test_loc('cache/package/package.json')
+        from scancode import api
+        package = api.get_package_infos(test_file)
+
+        test_dir = self.get_temp_dir()
+        cache = ScanCache(test_dir)
+        cache.put_infos(path='abc', file_infos=dict(sha1='def'))
+        cache.put_scan(path='abc', file_infos=dict(sha1='def'), scan_result=package)