From 1a6f8d7b0780c05e97c805e16e49c0be6d6e743e Mon Sep 17 00:00:00 2001
From: Ryn Daniels <ryn@hashicorp.com>
Date: Wed, 8 May 2019 15:50:04 +0200
Subject: [PATCH] Schema validation to ensure that repo tags don't have capital
 letters

---
 github/resource_github_repository.go      |  7 ++++++-
 github/resource_github_repository_test.go | 13 +++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/github/resource_github_repository.go b/github/resource_github_repository.go
index 233396e37a..498484ecdd 100644
--- a/github/resource_github_repository.go
+++ b/github/resource_github_repository.go
@@ -5,9 +5,11 @@ import (
 	"fmt"
 	"log"
 	"net/http"
+	"regexp"
 
 	"github.com/google/go-github/v25/github"
 	"github.com/hashicorp/terraform/helper/schema"
+	"github.com/hashicorp/terraform/helper/validation"
 )
 
 func resourceGithubRepository() *schema.Resource {
@@ -100,8 +102,11 @@ func resourceGithubRepository() *schema.Resource {
 			},
 			"topics": {
 				Type:     schema.TypeSet,
-				Elem:     &schema.Schema{Type: schema.TypeString},
 				Optional: true,
+				Elem: &schema.Schema{
+					Type:         schema.TypeString,
+					ValidateFunc: validation.StringMatch(regexp.MustCompile(`^[a-z0-9][a-z0-9-]*$`), "must include only lowercase alphanumeric characters or hyphens and cannot start with a hyphen"),
+				},
 			},
 
 			"full_name": {
diff --git a/github/resource_github_repository_test.go b/github/resource_github_repository_test.go
index a03442c970..a7dcf9ded6 100644
--- a/github/resource_github_repository_test.go
+++ b/github/resource_github_repository_test.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"regexp"
 	"sort"
 	"strings"
 	"testing"
@@ -277,6 +278,18 @@ func TestAccGithubRepository_templates(t *testing.T) {
 		Providers:    testAccProviders,
 		CheckDestroy: testAccCheckGithubRepositoryDestroy,
 		Steps: []resource.TestStep{
+			{
+				Config:      testAccGithubRepositoryConfigTopics(randString, `"TOPIC"`),
+				ExpectError: regexp.MustCompile(`must include only lowercase alphanumeric characters or hyphens and cannot start with a hyphen`),
+			},
+			{
+				Config:      testAccGithubRepositoryConfigTopics(randString, `"-topic"`),
+				ExpectError: regexp.MustCompile(`must include only lowercase alphanumeric characters or hyphens and cannot start with a hyphen`),
+			},
+			{
+				Config:      testAccGithubRepositoryConfigTopics(randString, `"töpic"`),
+				ExpectError: regexp.MustCompile(`must include only lowercase alphanumeric characters or hyphens and cannot start with a hyphen`),
+			},
 			{
 				Config: testAccGithubRepositoryConfigTemplates(randString),
 				Check: resource.ComposeTestCheckFunc(