From aacfc0194559a404aac3eefb819a25e1b7ea8a46 Mon Sep 17 00:00:00 2001
From: Chris Marchesi <chrism@vancluevertech.com>
Date: Sun, 27 Aug 2017 09:50:21 -0700
Subject: [PATCH 1/2] helper/validation: Add ValidateListUniqueStrings

Add the ValidateListUniqueStrings function, which is a ValidateFunc that
ensures a list has no duplicate items in it. It's useful for when a list
is needed over a set because order matters, yet the items still need to
be unique.
---
 helper/validation/validation.go      | 14 ++++++++++++++
 helper/validation/validation_test.go | 23 +++++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/helper/validation/validation.go b/helper/validation/validation.go
index 221433b7c..def3ca24f 100644
--- a/helper/validation/validation.go
+++ b/helper/validation/validation.go
@@ -144,3 +144,17 @@ func ValidateJsonString(v interface{}, k string) (ws []string, errors []error) {
 	}
 	return
 }
+
+// ValidateListUniqueStrings is a ValidateFunc that ensures a list has no
+// duplicate items in it. It's useful for when a list is needed over a set
+// because order matters, yet the items still need to be unique.
+func ValidateListUniqueStrings(v interface{}, k string) (ws []string, errors []error) {
+	for n1, v1 := range v.([]interface{}) {
+		for n2, v2 := range v.([]interface{}) {
+			if v1.(string) == v2.(string) && n1 != n2 {
+				errors = append(errors, fmt.Errorf("%q: duplicate entry - %s", k, v1.(string)))
+			}
+		}
+	}
+	return
+}
diff --git a/helper/validation/validation_test.go b/helper/validation/validation_test.go
index 0ca847fe6..fccffe805 100644
--- a/helper/validation/validation_test.go
+++ b/helper/validation/validation_test.go
@@ -166,6 +166,25 @@ func TestValidateJsonString(t *testing.T) {
 	}
 }
 
+func TestValidateListUniqueStrings(t *testing.T) {
+	runTestCases(t, []testCase{
+		{
+			val: []interface{}{"foo", "bar"},
+			f:   ValidateListUniqueStrings,
+		},
+		{
+			val:         []interface{}{"foo", "bar", "foo"},
+			f:           ValidateListUniqueStrings,
+			expectedErr: regexp.MustCompile("duplicate entry - foo"),
+		},
+		{
+			val:         []interface{}{"foo", "bar", "foo", "baz", "bar"},
+			f:           ValidateListUniqueStrings,
+			expectedErr: regexp.MustCompile("duplicate entry - (?:foo|bar)"),
+		},
+	})
+}
+
 func runTestCases(t *testing.T, cases []testCase) {
 	matchErr := func(errs []error, r *regexp.Regexp) bool {
 		// err must match one provided
@@ -185,6 +204,10 @@ func runTestCases(t *testing.T, cases []testCase) {
 			continue
 		}
 
+		if len(errs) != 0 && tc.expectedErr == nil {
+			t.Fatalf("expected test case %d to produce no errors, got %v", i, errs)
+		}
+
 		if !matchErr(errs, tc.expectedErr) {
 			t.Fatalf("expected test case %d to produce error matching \"%s\", got %v", i, tc.expectedErr, errs)
 		}

From b0152f6be36757c27941375c882840393a4cec93 Mon Sep 17 00:00:00 2001
From: Chris Marchesi <chrism@vancluevertech.com>
Date: Mon, 28 Aug 2017 13:49:11 -0700
Subject: [PATCH 2/2] Add newline to end of validation.go

---
 helper/validation/validation.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/helper/validation/validation.go b/helper/validation/validation.go
index 421c91442..8fc30478a 100644
--- a/helper/validation/validation.go
+++ b/helper/validation/validation.go
@@ -168,4 +168,4 @@ func ValidateRegexp(v interface{}, k string) (ws []string, errors []error) {
 		errors = append(errors, fmt.Errorf("%q: %s", k, err))
 	}
 	return
-}
\ No newline at end of file
+}