Add ensure-file parser package.

cipd/client/cipd/ensure/bad_test.go

Index: cipd/client/cipd/ensure/bad_test.go
diff --git a/cipd/client/cipd/ensure/bad_test.go b/cipd/client/cipd/ensure/bad_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..794a38c418614fe719276fe112bcf72a57c233d7
--- /dev/null
+++ b/cipd/client/cipd/ensure/bad_test.go
@@ -0,0 +1,187 @@
+// Copyright 2017 The LUCI Authors. All rights reserved.
+// Use of this source code is governed under the Apache License, Version 2.0
+// that can be found in the LICENSE file.
+
+package ensure
+
+import (
+	"bytes"
+	"testing"
+
+	. "github.com/luci/luci-go/common/testing/assertions"
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+var badEnsureFiles = []struct {
+	name string
+	file string
+	err  string
+}{
+	{
+		"too many tokens",
+		"this has too many tokens",
+		"bad version",
+	},
+
+	{
+		"no version",
+		"just/a/package",
+		"bad version",
+	},
+
+	{
+		"empty directive",
+		"@ foobar",
+		`unknown @directive: "@"`,
+	},
+
+	{
+		"unknown directive",
+		"@nerbs foobar",
+		`unknown @directive: "@nerbs"`,
+	},
+
+	{
+		"windows root",
+		"@root folder\\thing",
+		`bad root path: backslashes not allowed`,
+	},
+
+	{
+		"messy root",
+		"@root folder/../something",
+		`bad root path: "folder/../something" (should be "something")`,
+	},
+
+	{
+		"relative root",
+		"@root ../../something",
+		`bad root path: invalid ".": "../../something"`,
+	},
+
+	{
+		"absolute root",
+		"@root /etc",
+		`bad root path: absolute paths not allowed`,
+	},
+
+	{
+		"extra slashes",
+		"@root //foo/bar/baz",
+		`bad root path`,
+	},
+
+	{
+		"windows style",
+		"@root c:/foo/bar/baz",
+		`bad root path`,
+	},
+
+	{
+		"empty setting",
+		"$ something",
+		`unknown $setting: "$"`,
+	},
+
+	{
+		"bad url",
+		"$serviceurl ://sad.url",
+		"url is invalid",
+	},
+
+	{
+		"too many urls",
+		f(
+			"$serviceurl https://something.example.com",
+			"$serviceurl https://something.else.example.com",
+		),
+		"$ServiceURL may only be set once per file",
+	},
+
+	{
+		"bad setting",
+		"$nurbs thingy",
+		`unknown $setting: "$nurbs"`,
+	},
+
+	{
+		"bad template",
+		"foo/bar/${not_good} version",
+		"failed to resolve package template",
+	},
+
+	{
+		"bad template (2)",
+		"foo/bar/$not_good version",
+		"unable to process some variables",
+	},
+
+	{
+		"duplicate package (literal)",
+		f(
+			"some/package/something version",
+			"some/package/something latest",
+		),
+		`duplicate package in root "": "some/package/something": defined on line 1 and 2`,
+	},
+
+	{
+		"duplicate package (template)",
+		f(
+			"some/package/${arch} version",
+			"some/other/package canary",
+			"some/package/test_arch latest",
+		),
+		`duplicate package in root "": "some/package/test_arch": defined on line 1 and 3`,
+	},
+
+	{
+		"bad version resolution",
+		f(
+			"some/package/something error_version",
+		),
+		`failed to resolve package version (line 1)`,
+	},
+
+	{
+		"late setting (pkg)",
+		f(
+			"some/package version",
+			"",
+			"$ServiceURL https://something.example.com",
+		),
+		`$setting found after non-$setting statements`,
+	},
+
+	{
+		"late setting (directive)",
+		f(
+			"@Root some/path",
+			"",
+			"$ServiceURL https://something.example.com",
+		),
+		`$setting found after non-$setting statements`,
+	},
+}
+
+func TestBadEnsureFiles(t *testing.T) {
+	t.Parallel()
+
+	Convey("bad ensure files", t, func() {
+		for _, tc := range badEnsureFiles {
+			Convey(tc.name, func() {
+				buf := bytes.NewBufferString(tc.file)
+				f, err := ParseFile(buf)
+				if err != nil {
+					So(f, ShouldBeNil)
+					So(err, ShouldErrLike, tc.err)
+				} else {
+					So(f, ShouldNotBeNil)
+					rf, err := f.ResolveWith("test_arch", "test_plat", testResolver)
+					So(rf, ShouldBeNil)
+					So(err, ShouldErrLike, tc.err)
+				}
+			})
+		}
+	})
+}