1 files changed, 51 insertions, 0 deletions
diff --git a/tests/test_asyncio/mocks.py b/tests/test_asyncio/mocks.py
new file mode 100644
index 0000000..89bd9c0
--- /dev/null
+++ b/tests/test_asyncio/mocks.py
@@ -0,0 +1,51 @@
+import asyncio
+
+# Helper Mocking classes for the tests.
+
+
+class MockStream:
+    """
+    A class simulating an asyncio input buffer, optionally raising a
+    special exception every other read.
+    """
+
+    class TestError(BaseException):
+        pass
+
+    def __init__(self, data, interrupt_every=0):
+        self.data = data
+        self.counter = 0
+        self.pos = 0
+        self.interrupt_every = interrupt_every
+
+    def tick(self):
+        self.counter += 1
+        if not self.interrupt_every:
+            return
+        if (self.counter % self.interrupt_every) == 0:
+            raise self.TestError()
+
+    async def read(self, want):
+        self.tick()
+        want = 5
+        result = self.data[self.pos : self.pos + want]
+        self.pos += len(result)
+        return result
+
+    async def readline(self):
+        self.tick()
+        find = self.data.find(b"\n", self.pos)
+        if find >= 0:
+            result = self.data[self.pos : find + 1]
+        else:
+            result = self.data[self.pos :]
+        self.pos += len(result)
+        return result
+
+    async def readexactly(self, length):
+        self.tick()
+        result = self.data[self.pos : self.pos + length]
+        if len(result) < length:
+            raise asyncio.IncompleteReadError(result, None)
+        self.pos += len(result)
+        return result