[vpython] Add conditional packages based on PEP425

vpython/spec/match_test.go

Index: vpython/spec/match_test.go
diff --git a/vpython/spec/match_test.go b/vpython/spec/match_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..b7e9af803d9cda3e690c41a8bc8159df94efec3c
--- /dev/null
+++ b/vpython/spec/match_test.go
@@ -0,0 +1,160 @@
+// 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 spec
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+
+	"github.com/luci/luci-go/vpython/api/vpython"
+
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+func mkTag(version, abi, arch string) *vpython.Pep425Tag {
+	return &vpython.Pep425Tag{
+		Version: version,
+		Abi:     abi,
+		Arch:    arch,
+	}
+}
+
+func tagString(tags []*vpython.Pep425Tag) string {
+	parts := make([]string, len(tags))
+	for i, tag := range tags {
+		parts[i] = tag.TagString()
+	}
+	return strings.Join(parts, ", ")
+}
+
+func TestPEP425Matches(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		tags       []*vpython.Pep425Tag
+		matches    []*vpython.Pep425Tag
+		notMatches []*vpython.Pep425Tag
+	}{
+		{
+			tags: nil,
+			notMatches: []*vpython.Pep425Tag{
+				mkTag("", "", ""),
+				mkTag("cp27", "cp27mu", "manylinux1_x86_64"),
+			},
+		},
+		{
+			tags: []*vpython.Pep425Tag{
+				mkTag("cp27", "cp27mu", "manylinux1_x86_64"),
+				mkTag("py2", "cp27m", "macosx_10_9_universal"),
+			},
+			matches: []*vpython.Pep425Tag{
+				mkTag("cp27", "", ""),
+				mkTag("", "cp27mu", ""),
+				mkTag("", "", "manylinux1_x86_64"),
+				mkTag("py2", "", ""),
+				mkTag("", "cp27m", ""),
+				mkTag("", "", "macosx_10_9_universal"),
+				mkTag("", "cp27mu", "manylinux1_x86_64"),
+			},
+			notMatches: []*vpython.Pep425Tag{
+				mkTag("", "", ""),
+				mkTag("cp27", "cp27mu", "win_amd64"),
+				mkTag("cp27", "cp27mu", "macosx_10_9_universal"),
+			},
+		},
+		{
+			tags: []*vpython.Pep425Tag{
+				mkTag("cp27", "cp27mu", ""),
+			},
+			matches: []*vpython.Pep425Tag{
+				mkTag("cp27", "cp27mu", ""),
+			},
+			notMatches: []*vpython.Pep425Tag{
+				mkTag("", "", ""),
+				mkTag("cp27", "cp27mu", "otherArch"),
+			},
+		},
+	}
+
+	Convey(`Test cases for PEP425 tag matching`, t, func() {
+		for _, tc := range testCases {
+			Convey(fmt.Sprintf(`With system tags: %s`, tagString(tc.tags)), func() {
+				for _, m := range tc.matches {
+					Convey(fmt.Sprintf(`Tag matches: %s`, m.TagString()), func() {
+						So(PEP425Matches(m, tc.tags), ShouldBeTrue)
+					})
+				}
+
+				for _, m := range tc.notMatches {
+					Convey(fmt.Sprintf(`Tag doesn't match: %s`, m.TagString()), func() {
+						So(PEP425Matches(m, tc.tags), ShouldBeFalse)
+					})
+				}
+			})
+		}
+	})
+}
+
+func TestPackageMatches(t *testing.T) {
+	t.Parallel()
+
+	mkPkg := func(name string, tags ...*vpython.Pep425Tag) *vpython.Spec_Package {
+		return &vpython.Spec_Package{
+			Name:     name,
+			MatchTag: tags,
+		}
+	}
+
+	testCases := []struct {
+		tags         []*vpython.Pep425Tag
+		matchPkgs    []*vpython.Spec_Package
+		notMatchPkgs []*vpython.Spec_Package
+	}{
+		{
+			tags: nil,
+			matchPkgs: []*vpython.Spec_Package{
+				mkPkg("NoTags"),
+			},
+			notMatchPkgs: []*vpython.Spec_Package{
+				mkPkg("EmptyMatch", mkTag("", "", "")),
+				mkPkg("MissingMatch", mkTag("cp27", "cp27mu", "manylinux1_x86_64")),
+			},
+		},
+		{
+			tags: []*vpython.Pep425Tag{
+				mkTag("cp27", "cp27mu", "manylinux1_x86_64"),
+				mkTag("py2", "cp27m", "macosx_10_9_universal"),
+			},
+			matchPkgs: []*vpython.Spec_Package{
+				mkPkg("NoTags"),
+				mkPkg("OneMatchingTag", mkTag("cp27", "", "")),
+				mkPkg("MultipleMatchingTag", mkTag("cp27", "", ""), mkTag("", "cp27m", "")),
+			},
+			notMatchPkgs: []*vpython.Spec_Package{
+				mkPkg("EmptyMatch", mkTag("", "", "")),
+				mkPkg("MissingMatch", mkTag("none", "none", "none")),
+			},
+		},
+	}
+
+	Convey(`Test cases for package tag matching`, t, func() {
+		for _, tc := range testCases {
+			Convey(fmt.Sprintf(`With system tags: %s`, tagString(tc.tags)), func() {
+				for _, m := range tc.matchPkgs {
+					Convey(fmt.Sprintf(`Package %q matches: %s`, m.Name, tagString(m.MatchTag)), func() {
+						So(PackageMatches(m, tc.tags), ShouldBeTrue)
+					})
+				}
+
+				for _, m := range tc.notMatchPkgs {
+					Convey(fmt.Sprintf(`Package %q doesn't match: %s`, m.Name, tagString(m.MatchTag)), func() {
+						So(PackageMatches(m, tc.tags), ShouldBeFalse)
+					})
+				}
+			})
+		}
+	})
+}