From ac26608e705861c536f8be2cc57aa0fc7e2f203d Mon Sep 17 00:00:00 2001
From: John-Mark Gurney <jmg@funkthat.com>
Date: Tue, 4 Feb 2020 12:55:39 -0800
Subject: [PATCH] add support for loading via https urls...

---
 casimport/__init__.py            | 62 ++++++++++++++++++++++++++++++--
 fixtures/randpkg/cas_aliases.txt |  1 +
 2 files changed, 61 insertions(+), 2 deletions(-)

diff --git a/casimport/__init__.py b/casimport/__init__.py
index 4b66817..9e7f4b4 100644
--- a/casimport/__init__.py
+++ b/casimport/__init__.py
@@ -105,6 +105,19 @@ def tempattrset(obj, key, value):
 		else:
 			delattr(obj, key)
 
+class HTTPSCAS(object):
+	def fetch_data(self, url):
+		if url.scheme != 'https':
+			raise ValueError('cannot handle scheme %s' %
+			    repr(url.scheme))
+
+		url = urllib.parse.urlunparse(url)
+		with urllib.request.urlopen(url) as req:
+			if req.status // 100 != 2:
+				raise RuntimeError('bad fetch')
+
+			return req.read()
+
 class IPFSCAS(object):
 	gwhost = 'gateway.ipfs.io'
 	gwhost = 'cloudflare-ipfs.com'
@@ -117,6 +130,7 @@ class IPFSCAS(object):
 		if url.scheme != 'ipfs':
 			raise ValueError('cannot handle scheme %s' %
 			    repr(url.scheme))
+
 		gwurl = self.make_url(url)
 
 		with urllib.request.urlopen(gwurl) as req:
@@ -334,6 +348,7 @@ def defaultinit(casf):
 
 	casf.register(FileDirCAS(cachedir))
 	casf.register(IPFSCAS())
+	casf.register(HTTPSCAS())
 
 # The global version
 _casfinder = CASFinder()
@@ -461,8 +476,11 @@ class Test(unittest.TestCase):
 				# it can be imported
 				from cas.v1_f_330884aa2febb5e19fb7194ec6a69ed11dd3d77122f1a5175ee93e73cf0161c3 import hello
 
-				# and that the last loader is the IPFSCAS
-				self.assertIsInstance(f._loaders[-1], IPFSCAS)
+				# and that the second loader is the IPFSCAS
+				self.assertIsInstance(f._loaders[1], IPFSCAS)
+
+				# and that the third loader is the HTTPSCAS
+				self.assertIsInstance(f._loaders[2], HTTPSCAS)
 
 			with CASFinder() as f:
 				defaultinit(f)
@@ -484,9 +502,11 @@ class Test(unittest.TestCase):
 				'hello': [
 					'hash://sha256/330884aa2febb5e19fb7194ec6a69ed11dd3d77122f1a5175ee93e73cf0161c3?type=text/x-python',
 					'ipfs://bafkreibtbcckul7lwxqz7nyzj3dknhwrdxj5o4jc6gsroxxjhzz46albym',
+					'https://www.funkthat.com/gitea/jmg/casimport/raw/commit/753e64f53c73d9d1afc4d8a617edb9d3542dcea2/fixtures/hello.py',
 				],
 				'hash://sha256/330884aa2febb5e19fb7194ec6a69ed11dd3d77122f1a5175ee93e73cf0161c3': [
 					'ipfs://bafkreibtbcckul7lwxqz7nyzj3dknhwrdxj5o4jc6gsroxxjhzz46albym',
+					'https://www.funkthat.com/gitea/jmg/casimport/raw/commit/753e64f53c73d9d1afc4d8a617edb9d3542dcea2/fixtures/hello.py',
 				],
 			})
 
@@ -592,6 +612,44 @@ class Test(unittest.TestCase):
 		with self.assertRaises(RuntimeError):
 			ipfs.fetch_data(hashurl)
 
+	# Note: mostly copied from above, test_ipfscasloader
+	@mock.patch('urllib.request.urlopen')
+	def test_httpscasloader(self, uomock):
+		# prep return test data
+		with open(self.fixtures / 'hello.py') as fp:
+			# that returns the correct data
+			httpsdata = fp.read()
+
+		# that the https CAS loader
+		httpsldr = HTTPSCAS()
+
+		# that the request is successfull
+		uomock.return_value.__enter__.return_value.status = 200
+
+		# and returns the correct data
+		uomock.return_value.__enter__.return_value.read.return_value = httpsdata
+
+		# that when called
+		hashurl = urllib.parse.urlparse('https://www.funkthat.com/gitea/jmg/casimport/raw/commit/753e64f53c73d9d1afc4d8a617edb9d3542dcea2/fixtures/hello.py')
+		data = httpsldr.fetch_data(hashurl)
+
+		# it opens the correct url
+		uomock.assert_called_with('https://www.funkthat.com/gitea/jmg/casimport/raw/commit/753e64f53c73d9d1afc4d8a617edb9d3542dcea2/fixtures/hello.py')
+
+		# and returns the correct data
+		self.assertEqual(data, httpsdata)
+
+		with self.assertRaises(ValueError):
+			# that a hash url fails
+			httpsldr.fetch_data(urllib.parse.urlparse('hash://sha256/asldfkj'))
+
+		# that when the request fails
+		uomock.return_value.__enter__.return_value.status = 400
+
+		# it raises a RuntimeError
+		with self.assertRaises(RuntimeError):
+			httpsldr.fetch_data(hashurl)
+
 	def test_overlappingaliases(self):
 		# make sure that an aliases file is consistent and does not
 		# override other urls.  That is that any hashes are
diff --git a/fixtures/randpkg/cas_aliases.txt b/fixtures/randpkg/cas_aliases.txt
index f5dd8e4..0b9f323 100644
--- a/fixtures/randpkg/cas_aliases.txt
+++ b/fixtures/randpkg/cas_aliases.txt
@@ -1,2 +1,3 @@
 hello	hash://sha256/330884aa2febb5e19fb7194ec6a69ed11dd3d77122f1a5175ee93e73cf0161c3?type=text/x-python
 hello	ipfs://bafkreibtbcckul7lwxqz7nyzj3dknhwrdxj5o4jc6gsroxxjhzz46albym
+hello	https://www.funkthat.com/gitea/jmg/casimport/raw/commit/753e64f53c73d9d1afc4d8a617edb9d3542dcea2/fixtures/hello.py