Add test_list command, to enumerate unit and e2e tests.

This uses go/parser and go/ast to analyze all test files in ~1 second.
It only recognizes a few simple structures that the tests all have, and
modifies a few tests to fit expected structure better.

This is part of an effort to ensure all tests have owners, by having a
verify check to catch new tests being added without an owner.

test/list/main_test.go

@@ -0,0 +1,111 @@
+/*
+Copyright 2016 The Kubernetes 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.
+*/
+
+package main
+
+import (
+	"errors"
+	"path/filepath"
+	"reflect"
+	"testing"
+)
+
+var collectCases = []struct {
+	filename string
+	code     string
+	output   []Test
+}{
+	// Empty: no tests
+	{"e2e/util_test.go", "", []Test{}},
+	// Go unit test
+	{"test/list/main_test.go", `
+var num = 3
+func Helper(x int) { return x / 0 }
+func TestStuff(t *Testing.T) {
+}`, []Test{{"test/list/main_test.go:5:1", "k8s.io/kubernetes/test/list", "TestStuff"}},
+	},
+	// Describe + It
+	{"e2e/foo.go", `
+var _ = Describe("Feature", func() {
+	It("should work properly", func() {})
+})`, []Test{{"e2e/foo.go:4:2", "[k8s.io] Feature", "should work properly"}},
+	},
+	// KubeDescribe + It
+	{"e2e/foo.go", `
+var _ = framework.KubeDescribe("Feature", func() {
+	It("should work properly", func() {})
+})`, []Test{{"e2e/foo.go:4:2", "[k8s.io] Feature", "should work properly"}},
+	},
+	// KubeDescribe + Context + It
+	{"e2e/foo.go", `
+var _ = framework.KubeDescribe("Feature", func() {
+	Context("when offline", func() {
+		It("should work", func() {})
+	})
+})`, []Test{{"e2e/foo.go:5:3", "[k8s.io] Feature when offline", "should work"}},
+	},
+	// KubeDescribe + It(Sprintf)
+	{"e2e/foo.go", `
+var _ = framework.KubeDescribe("Feature", func() {
+	It(fmt.Sprintf("handles %d nodes", num), func() {})
+})`, []Test{{"e2e/foo.go:4:2", "[k8s.io] Feature", "handles * nodes"}},
+	},
+	// KubeDescribe + Sprintf + It(var)
+	{"e2e/foo.go", `
+var _ = framework.KubeDescribe("Feature", func() {
+	arg := fmt.Sprintf("does %s and %v at %d", task, desc, num)
+	It(arg, func() {})
+})`, []Test{{"e2e/foo.go:5:2", "[k8s.io] Feature", "does * and * at *"}},
+	},
+	// KubeDescribe + string + It(var)
+	{"e2e/foo.go", `
+var _ = framework.KubeDescribe("Feature", func() {
+	arg := "does stuff"
+	It(arg, func() {})
+})`, []Test{{"e2e/foo.go:5:2", "[k8s.io] Feature", "does stuff"}},
+	},
+	// KubeDescribe + It(unknown)
+	{"e2e/foo.go", `
+var _ = framework.KubeDescribe("Feature", func() {
+	It(mysteryFunc(), func() {})
+})`, []Test{{"e2e/foo.go:4:2", "[k8s.io] Feature", "*"}},
+	},
+}
+
+func TestCollect(t *testing.T) {
+	for _, test := range collectCases {
+		code := "package test\n" + test.code
+		tests := collect(test.filename, code)
+		if !reflect.DeepEqual(tests, test.output) {
+			t.Errorf("code:\n%s\ngot  %v\nwant %v",
+				code, tests, test.output)
+		}
+	}
+}
+
+func TestHandlePath(t *testing.T) {
+	tl := testList{}
+	e := errors.New("ex")
+	if tl.handlePath("foo", nil, e) != e {
+		t.Error("handlePath not returning errors")
+	}
+	if tl.handlePath("foo.txt", nil, nil) != nil {
+		t.Error("should skip random files")
+	}
+	if tl.handlePath("third_party/a_test.go", nil, nil) != filepath.SkipDir {
+		t.Error("should skip third_party")
+	}
+}