Open-source some Python rules unit tests

This is a precursor to fixing #1446.

RELNOTES: None
PiperOrigin-RevId: 212267168

src/main/java/com/google/devtools/build/lib/bazel/rules/python/BazelPyRuleClasses.java

@@ -108,6 +108,9 @@ A string specifying the Python major version(s) that the <code>.py</code> source
           .add(attr("srcs_version", STRING)
               .value(PythonVersion.defaultSrcsVersion().toString())
               .allowedValues(new AllowedValueSet(PythonVersion.getAllValues())))
+          // TODO(brandjon): Consider adding to py_interpreter a .mandatoryNativeProviders() of
+          // BazelPyRuntimeProvider. (Add a test case to PythonConfigurationTest for violations
+          // of this requirement.)
           .add(attr(":py_interpreter", LABEL).value(PY_INTERPRETER))
           // do not depend on lib2to3:2to3 rule, because it creates circular dependencies
           // 2to3 is itself written in Python and depends on many libraries.

src/test/java/com/google/devtools/build/lib/BUILD

@@ -55,6 +55,7 @@ filegroup(
         "//src/test/java/com/google/devtools/build/lib/rules/cpp:srcs",
         "//src/test/java/com/google/devtools/build/lib/rules/objc:srcs",
         "//src/test/java/com/google/devtools/build/lib/rules/platform:srcs",
+        "//src/test/java/com/google/devtools/build/lib/rules/python:srcs",
         "//src/test/java/com/google/devtools/build/lib/rules/repository:srcs",
         "//src/test/java/com/google/devtools/build/lib/skyframe/packages:srcs",
         "//src/test/java/com/google/devtools/build/lib/skyframe/serialization:srcs",

src/test/java/com/google/devtools/build/lib/rules/python/BUILD

@@ -0,0 +1,44 @@
+package(
+    default_testonly = True,
+)
+
+filegroup(
+    name = "srcs",
+    testonly = 0,
+    srcs = glob(["**"]),
+    visibility = ["//src:__subpackages__"],
+)
+
+test_suite(
+    name = "PythonTests",
+    tests = [
+        ":BazelPythonConfigurationTest",
+        ":PythonConfigurationTest",
+    ],
+)
+
+java_test(
+    name = "BazelPythonConfigurationTest",
+    srcs = ["BazelPythonConfigurationTest.java"],
+    deps = [
+        "//src/main/java/com/google/devtools/build/lib:bazel-rules",
+        "//src/main/java/com/google/devtools/build/lib:build-base",
+        "//src/main/java/com/google/devtools/common/options",
+        "//src/test/java/com/google/devtools/build/lib:analysis_testutil",
+        "//src/test/java/com/google/devtools/build/lib:testutil",
+        "//third_party:junit4",
+        "//third_party:truth",
+    ],
+)
+
+java_test(
+    name = "PythonConfigurationTest",
+    srcs = ["PythonConfigurationTest.java"],
+    deps = [
+        "//src/main/java/com/google/devtools/common/options",
+        "//src/test/java/com/google/devtools/build/lib:analysis_testutil",
+        "//src/test/java/com/google/devtools/build/lib:testutil",
+        "//third_party:junit4",
+        "//third_party:truth",
+    ],
+)

src/test/java/com/google/devtools/build/lib/rules/python/BazelPythonConfigurationTest.java

@@ -0,0 +1,65 @@
+// Copyright 2018 The Bazel Authors. All rights reserved.
+//
+// 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.
+
+package com.google.devtools.build.lib.rules.python;
+
+import static com.google.common.truth.Truth.assertThat;
+import static com.google.devtools.build.lib.testutil.MoreAsserts.assertThrows;
+
+import com.google.devtools.build.lib.analysis.config.InvalidConfigurationException;
+import com.google.devtools.build.lib.analysis.util.ConfigurationTestCase;
+import com.google.devtools.build.lib.bazel.rules.python.BazelPythonConfiguration;
+import com.google.devtools.common.options.OptionsParsingException;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Tests for {@link BazelPythonConfiguration}. */
+@RunWith(JUnit4.class)
+public class BazelPythonConfigurationTest extends ConfigurationTestCase {
+
+  @Test
+  public void pythonTop() throws Exception {
+    scratch.file(
+        "a/BUILD",
+        "py_runtime(name='b', files=[], interpreter='c')");
+    BazelPythonConfiguration config = create("--python_top=//a:b")
+        .getFragment(BazelPythonConfiguration.class);
+    assertThat(config.getPythonTop()).isNotNull();
+  }
+
+  @Test
+  public void pythonTop_malformedLabel() {
+    OptionsParsingException expected =
+        assertThrows(
+            OptionsParsingException.class,
+            () -> create("--python_top=//a:!b:"));
+    assertThat(expected).hasMessageThat().contains("While parsing option --python_top");
+  }
+
+  @Test
+  public void pythonPath() throws Exception {
+    BazelPythonConfiguration config = create("--python_path=/pajama")
+        .getFragment(BazelPythonConfiguration.class);
+    assertThat(config.getPythonPath()).isEqualTo("/pajama");
+  }
+
+  @Test
+  public void pythonPathMustBeAbsolute() {
+    InvalidConfigurationException expected = assertThrows(
+        InvalidConfigurationException.class,
+        () -> create("--python_path=pajama"));
+    assertThat(expected).hasMessageThat().contains("python_path must be an absolute path");
+  }
+}

src/test/java/com/google/devtools/build/lib/rules/python/PythonConfigurationTest.java

@@ -0,0 +1,44 @@
+// Copyright 2018 The Bazel Authors. All rights reserved.
+//
+// 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.
+
+package com.google.devtools.build.lib.rules.python;
+
+import static com.google.common.truth.Truth.assertThat;
+import static com.google.devtools.build.lib.testutil.MoreAsserts.assertThrows;
+
+import com.google.devtools.build.lib.analysis.util.ConfigurationTestCase;
+import com.google.devtools.common.options.OptionsParsingException;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Tests for {@link PythonConfiguration}. */
+@RunWith(JUnit4.class)
+public class PythonConfigurationTest extends ConfigurationTestCase {
+
+  @Test
+  public void invalidForcePythonValue_NotATargetValue() throws Exception {
+    checkError("'--force_python' argument must be 'PY2' or 'PY3'", "--force_python=PY2AND3");
+  }
+
+  @Test
+  public void invalidForcePythonValue_UnknownValue() {
+    OptionsParsingException expected =
+        assertThrows(
+            OptionsParsingException.class,
+            () -> create("--force_python=BEETLEJUICE"));
+    assertThat(expected).hasMessageThat()
+        .contains("While parsing option --force_python=BEETLEJUICE: Not a valid Python version");
+  }
+}