v.io/x/lib/envvar: make it easier to manipulate envvars that are paths.
Change-Id: Ifef4dca534a699ba3021b718d3d3d3311e19123c
diff --git a/envvar/.api b/envvar/.api
index d88baae..ec7414e 100644
--- a/envvar/.api
+++ b/envvar/.api
@@ -1,3 +1,4 @@
+pkg envvar, func AppendUsingSeparator(string, string, string) string
pkg envvar, func CopyMap(map[string]string) map[string]string
pkg envvar, func CopySlice([]string) []string
pkg envvar, func JoinKeyValue(string, string) string
@@ -7,6 +8,7 @@
pkg envvar, func MapToSlice(map[string]string) []string
pkg envvar, func MergeMaps(...map[string]string) map[string]string
pkg envvar, func MergeSlices(...[]string) []string
+pkg envvar, func PrependUsingSeparator(string, string, string) string
pkg envvar, func SliceToMap([]string) map[string]string
pkg envvar, func SortByKey([]string)
pkg envvar, func SplitKeyValue(string) (string, string)
diff --git a/envvar/envvar.go b/envvar/envvar.go
index f34df73..788f948 100644
--- a/envvar/envvar.go
+++ b/envvar/envvar.go
@@ -145,6 +145,24 @@
return value
}
+// PrependUsingSeparator prepends the parameter val to parameter existing using
+// separator to split the tokens in existing and to prepend val.
+// PrependUsingSeparator uses SplitTokens on the existing string
+// and hence filters out empty tokens, so "A::B:" becomes "A:B".
+func PrependUsingSeparator(val, existing, separator string) string {
+ tmp := SplitTokens(existing, separator)
+ return JoinTokens(append([]string{val}, tmp...), separator)
+}
+
+// AppendUsingSeparator appends the parameter val to parameter existing using
+// separator to split the tokens in existing string and to append val.
+// AppendUsingSeparator uses SplitTokens on the existing string
+// and hence filters out empty tokens, so "A::B:" becomes "A:B".
+func AppendUsingSeparator(val, existing, separator string) string {
+ tmp := SplitTokens(existing, separator)
+ return JoinTokens(append(tmp, val), separator)
+}
+
// SortByKey sorts vars into ascending key order, where vars is expected to be
// in the []"key=value" slice representation.
func SortByKey(vars []string) {
diff --git a/envvar/envvar_test.go b/envvar/envvar_test.go
index e778c53..e2f9cc9 100644
--- a/envvar/envvar_test.go
+++ b/envvar/envvar_test.go
@@ -161,6 +161,40 @@
}
}
+func TestAppendPrepend(t *testing.T) {
+ tests := []struct {
+ Sep, Value, Existing, Result string
+ }{
+ {":", "Z", "", "Z"},
+ {":", "", "Z", "Z"},
+ {":", "", "", ""},
+ {":", "X", ":A:B", "X:A:B"},
+ {":", "Y", "A:B", "Y:A:B"},
+ {":", "Z", "A:::B", "Z:A:B"},
+ {":", "Z", "A:::B:", "Z:A:B"},
+ }
+ for i, test := range tests {
+ if got, want := PrependUsingSeparator(test.Value, test.Existing, test.Sep), test.Result; got != want {
+ t.Errorf("SplitTokens(%d) got %v, want %v", i, got, want)
+ }
+ }
+ tests = []struct {
+ Sep, Value, Existing, Result string
+ }{
+ {":", "Z", "", "Z"},
+ {":", "", "Z", "Z"},
+ {":", "", "", ""},
+ {":", "X", ":A:B:", "A:B:X"},
+ {":", "Y", "A:B", "A:B:Y"},
+ {":", "Z", "A:::B", "A:B:Z"},
+ }
+ for i, test := range tests {
+ if got, want := AppendUsingSeparator(test.Value, test.Existing, test.Sep), test.Result; got != want {
+ t.Errorf("SplitTokens(%d) got %v, want %v", i, got, want)
+ }
+ }
+}
+
func TestSortByKey(t *testing.T) {
tests := []struct {
In, Sorted []string
