milo: Add SwarmBucket templating.

common/data/text/stringtemplate/template_test.go

Index: common/data/text/stringtemplate/template_test.go
diff --git a/common/data/text/stringtemplate/template_test.go b/common/data/text/stringtemplate/template_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..99dc2775ed37bc6d1f7e5541603cd2de12bda12b
--- /dev/null
+++ b/common/data/text/stringtemplate/template_test.go
@@ -0,0 +1,69 @@
+// 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 stringtemplate
+
+import (
+	"testing"
+
+	. "github.com/luci/luci-go/common/testing/assertions"
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+func TestResolve(t *testing.T) {
+	t.Parallel()
+
+	Convey(`Testing substitution resolution`, t, func() {
+		shouldResolve := func(v string, subst map[string]string) string {
+			val, err := Resolve(v, subst)
+			So(err, ShouldBeNil)
+			return val
+		}
+
+		resolveErr := func(v string) error {
+			_, err := Resolve(v, nil)
+			return err
+		}
+
+		Convey(`Can resolve a string without any substitutions.`, func() {
+			So(shouldResolve("", nil), ShouldEqual, "")
+			So(shouldResolve("foo", nil), ShouldEqual, "foo")
+			So(shouldResolve(`$${foo}`, nil), ShouldEqual, `${foo}`)
+		})
+
+		Convey(`Will error if there is an invalid substitution.`, func() {
+			So(resolveErr("$"), ShouldErrLike, "invalid template")
+			So(resolveErr("hello$"), ShouldErrLike, "invalid template")
+			So(resolveErr("foo-${bar"), ShouldErrLike, "invalid template")
+			So(resolveErr("${not valid}"), ShouldErrLike, "invalid template")
+
+			So(resolveErr("${uhoh}"), ShouldErrLike, "no substitution for")
+			So(resolveErr("$noooo"), ShouldErrLike, "no substitution for")
+		})
+
+		Convey(`With substitutions defined, can apply.`, func() {
+			m := map[string]string{
+				"pants":      "shirt",
+				"wear_pants": "12345",
+			}
+
+			So(shouldResolve("", m), ShouldEqual, "")
+
+			So(shouldResolve("$pants", m), ShouldEqual, "shirt")
+			So(shouldResolve("foo/$pants", m), ShouldEqual, "foo/shirt")
+
+			So(shouldResolve("${wear_pants}", m), ShouldEqual, "12345")
+			So(shouldResolve("foo/${wear_pants}", m), ShouldEqual, "foo/12345")
+			So(shouldResolve("foo/${wear_pants}/bar", m), ShouldEqual, "foo/12345/bar")
+			So(shouldResolve("${wear_pants}/bar", m), ShouldEqual, "12345/bar")
+			So(shouldResolve("foo/${wear_pants}/bar/${wear_pants}/baz", m), ShouldEqual, "foo/12345/bar/12345/baz")
+
+			So(shouldResolve(`$$pants`, m), ShouldEqual, "$pants")
+			So(shouldResolve(`$${pants}`, m), ShouldEqual, "${pants}")
+			So(shouldResolve(`$$$pants`, m), ShouldEqual, "$shirt")
+			So(shouldResolve(`$$${pants}`, m), ShouldEqual, "$shirt")
+			So(shouldResolve(`foo/${wear_pants}/bar/$${wear_pants}/baz`, m), ShouldEqual, `foo/12345/bar/${wear_pants}/baz`)
+		})
+	})
+}