tests: Add tests for the resource downloader

Change-Id: Ibc2685670dc50234b9b216226c03ed24c8bc9925
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/59089
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>

tests/pyunit/stdlib/resources/pyunit_downloader_checks.py

@@ -0,0 +1,139 @@
+# Copyright (c) 2022 The Regents of the University of California
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met: redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer;
+# redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution;
+# neither the name of the copyright holders nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+import unittest
+import tempfile
+import os
+from typing import Dict
+
+from gem5.resources.downloader import(
+    _get_resources_json_at_path,
+    _get_resources_json,
+    _resources_json_version_required,
+)
+
+class MD5FileTestSuite(unittest.TestCase):
+    """Test cases for gem5.resources.downloader"""
+
+    def create_temp_resources_json(self) -> str:
+        """
+        This creates a simple resource.json temp file for testing purposes.
+        """
+
+        file_contents = \
+            "{"  + f"\"version\" : \"{_resources_json_version_required()}\"," \
+            + """
+    "url_base" : "http://dist.gem5.org/dist/v21-2",
+    "previous-versions" : {},
+    "resources": [
+        {
+            "type": "resource",
+            "name" : "riscv-disk-img",
+            "documentation" : "A simple RISCV disk image based on busybox.",
+            "architecture": "RISCV",
+            "is_zipped" : true,
+            "md5sum" : "d6126db9f6bed7774518ae25aa35f153",
+            "url": "{url_base}/images/riscv/busybox/riscv-disk.img.gz",
+            "source" : "src/riscv-fs",
+            "additional_metadata" : {
+                "root_partition": null
+            }
+        },
+        {
+            "type": "resource",
+            "name" : "riscv-lupio-busybox-img",
+            "documentation" : "A RISCV disk image, based on busybox, to ...",
+            "architecture": "RISCV",
+            "is_zipped" : true,
+            "md5sum" : "e5bee8a31f45f4803f87c0d781553ccc",
+            "url": "{url_base}/images/riscv/busybox/riscv-lupio-busybox.img",
+            "source" : "src/lupv",
+            "additional_metadata" : {
+                "root_partition": "1"
+            }
+        }
+    ]
+}
+        """
+        file = tempfile.NamedTemporaryFile(mode="w", delete=False)
+        file.write(file_contents)
+        file.close()
+        return file.name
+
+    def verify_json(self, json: Dict) -> None:
+        """
+        This verifies the JSON file created in created in
+        "create_temp_resources_json" has been loaded correctly into a Python
+        dictionary.
+        """
+        self.assertTrue("resources" in json)
+        self.assertEquals(2, len(json["resources"]))
+        self.assertTrue("name" in json["resources"][0])
+        self.assertEquals("riscv-disk-img", json["resources"][0]["name"])
+        self.assertTrue("name" in json["resources"][1])
+        self.assertEquals("riscv-lupio-busybox-img",
+                          json["resources"][1]["name"])
+
+    def test_get_resources_json_at_path(self) -> None:
+        # Tests the gem5.resources.downloader._get_resources_json_at_path()
+        # function.
+
+        path = self.create_temp_resources_json()
+        json = _get_resources_json_at_path(path = path)
+
+        self.verify_json(json=json)
+
+        # Cleanup the temp file
+        os.remove(path)
+
+    def test_get_resources_json(self) -> None:
+        # Tests the gem5.resources.downloader._get_resources_json() function.
+
+        path = self.create_temp_resources_json()
+
+        # We set the "GEM5_RESOURCE_JSON" environment variable to allow using
+        # our test temp resources.json.
+        os.environ["GEM5_RESOURCE_JSON"] = path
+        json = _get_resources_json()
+        self.verify_json(json=json)
+
+        # Cleanup the temp file
+        os.remove(path)
+
+    def test_get_resources_json_invalid_url(self) -> None:
+        # Tests the gem5.resources.downloader._get_resources_json() function in
+        # case where an invalid url is passed as the URL/PATH of the
+        # resources.json file.
+
+        path = "NotAURLorFilePath"
+        os.environ["GEM5_RESOURCE_JSON"] = path
+        with self.assertRaises(Exception) as context:
+            _get_resources_json()
+
+        self.assertTrue(
+            f"Resources location '{path}' is not a valid path or URL." in \
+            str(context.exception)
+        )