Merge pull request #7876 from pfmoore/new_resolver_tests

Add some functional tests for the new resolver

tests/functional/test_new_resolver.py

+import json
+
+from tests.lib import create_basic_wheel_for_package
+
+
+def assert_installed(script, **kwargs):
+    ret = script.pip('list', '--format=json')
+    installed = set(
+        (val['name'], val['version'])
+        for val in json.loads(ret.stdout)
+    )
+    assert set(kwargs.items()) <= installed
+
+
+def test_new_resolver_can_install(script):
+    create_basic_wheel_for_package(
+        script,
+        "simple",
+        "0.1.0",
+    )
+    script.pip(
+        "install", "--unstable-feature=resolver",
+        "--no-cache-dir", "--no-index",
+        "--find-links", script.scratch_path,
+        "simple"
+    )
+    assert_installed(script, simple="0.1.0")
+
+
+def test_new_resolver_can_install_with_version(script):
+    create_basic_wheel_for_package(
+        script,
+        "simple",
+        "0.1.0",
+    )
+    script.pip(
+        "install", "--unstable-feature=resolver",
+        "--no-cache-dir", "--no-index",
+        "--find-links", script.scratch_path,
+        "simple==0.1.0"
+    )
+    assert_installed(script, simple="0.1.0")
+
+
+def test_new_resolver_picks_latest_version(script):
+    create_basic_wheel_for_package(
+        script,
+        "simple",
+        "0.1.0",
+    )
+    create_basic_wheel_for_package(
+        script,
+        "simple",
+        "0.2.0",
+    )
+    script.pip(
+        "install", "--unstable-feature=resolver",
+        "--no-cache-dir", "--no-index",
+        "--find-links", script.scratch_path,
+        "simple"
+    )
+    assert_installed(script, simple="0.2.0")
+
+
+def test_new_resolver_installs_dependencies(script):
+    create_basic_wheel_for_package(
+        script,
+        "base",
+        "0.1.0",
+        depends=["dep"],
+    )
+    create_basic_wheel_for_package(
+        script,
+        "dep",
+        "0.1.0",
+    )
+    script.pip(
+        "install", "--unstable-feature=resolver",
+        "--no-cache-dir", "--no-index",
+        "--find-links", script.scratch_path,
+        "base"
+    )
+    assert_installed(script, base="0.1.0", dep="0.1.0")