[REQUIRED FIRST] Fix lint by making pkg tests folders namespace pkgs

.coveragerc

@@ -4,4 +4,3 @@ omit =
     */setup.py
     */gen/*
     reference/*
-    opentelemetry-python-core/*

.pylintrc

@@ -7,7 +7,7 @@ extension-pkg-whitelist=
 
 # Add list of files or directories to be excluded. They should be base names, not
 # paths.
-ignore=CVS,gen,opentelemetry-python-core
+ignore=CVS,gen
 
 # Add files or directories matching the regex patterns to be excluded. The
 # regex matches against base names, not paths.

dev-requirements.txt

@@ -1,4 +1,4 @@
-pylint~=2.3
+pylint==2.4.4
 flake8~=3.7
 isort~=4.3
 black>=19.3b0,==19.*

instrumentation/opentelemetry-instrumentation-wsgi/tests/__init__.py

@@ -0,0 +1,23 @@
+# Copyright The OpenTelemetry Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.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.
+import pkg_resources
+
+# IMPORTANT: Only the wsgi module needs this because it is always the first
+# package that uses the `{rootdir}/*/tests/` path and gets installed by
+# `eachdist.py` and according to `eachdist.ini`.
+
+# Naming the tests module as a namespace package ensures that
+# relative imports will resolve properly for subsequent test packages,
+# as it enables searching for a composite of multiple test modules.
+pkg_resources.declare_namespace(__name__)

pyproject.toml

@@ -3,8 +3,7 @@ line-length = 79
 exclude = '''
 (
   /(
-    reference| # original files from DataDog
-    opentelemetry-python-core
+    reference # original files from DataDog
   )/
 )
 '''

tox.ini

@@ -262,16 +262,6 @@ commands =
 basepython: python3.8
 recreate = True
 deps =
-  -e {toxinidir}/opentelemetry-python-core/opentelemetry-proto
-  -e {toxinidir}/opentelemetry-python-core/opentelemetry-api
-  -e {toxinidir}/opentelemetry-python-core/opentelemetry-sdk
-  -e {toxinidir}/opentelemetry-python-core/opentelemetry-instrumentation
-  -e {toxinidir}/opentelemetry-python-core/opentelemetry-proto
-  -e {toxinidir}/opentelemetry-python-core/tests/util
-  -e {toxinidir}/opentelemetry-python-core/exporter/opentelemetry-exporter-jaeger
-  -e {toxinidir}/opentelemetry-python-core/exporter/opentelemetry-exporter-zipkin
-  -e {toxinidir}/opentelemetry-python-core/exporter/opentelemetry-exporter-prometheus
-  -e {toxinidir}/opentelemetry-python-core/exporter/opentelemetry-exporter-otlp
   -c dev-requirements.txt
   pylint
   flake8
@@ -282,6 +272,10 @@ deps =
   httpretty
 
 commands_pre =
+  python -m pip install {toxinidir}/opentelemetry-python-core/opentelemetry-api
+  python -m pip install {toxinidir}/opentelemetry-python-core/opentelemetry-sdk
+  python -m pip install {toxinidir}/opentelemetry-python-core/tests/util
+  python -m pip install {toxinidir}/opentelemetry-python-core/opentelemetry-instrumentation
   python scripts/eachdist.py install --editable --with-test-deps
 
 commands =