From 9a7ae7dddb0e9d6f41e741e2b994a8d2a947ea4b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Enrique=20Garc=C3=ADa=20Cota?= <kikito@gmail.com>
Date: Mon, 8 Jun 2020 20:20:57 +0200
Subject: [PATCH] wip-schema

---
 kong/plugins/zipkin/schema.lua | 18 +++++++++++++++++-
 spec/schema_spec.lua           | 20 ++++++++++++++++++++
 2 files changed, 37 insertions(+), 1 deletion(-)
 create mode 100644 spec/schema_spec.lua

diff --git a/kong/plugins/zipkin/schema.lua b/kong/plugins/zipkin/schema.lua
index 82aefe6..bd46d2d 100644
--- a/kong/plugins/zipkin/schema.lua
+++ b/kong/plugins/zipkin/schema.lua
@@ -25,6 +25,21 @@ local static_tag = Schema.define {
   },
 }
 
+local validate_static_tags = function(tags)
+  if type(tags) ~= "table" then
+    return true
+  end
+  local found = {}
+  for i = 1, #tags do
+    local name = tags[i].name
+    if found[name] then
+      return nil, "repeating tags are not allowed: " .. name
+    end
+    found[name] = true
+  end
+  return true
+end
+
 return {
   name = "zipkin",
   fields = {
@@ -40,7 +55,8 @@ return {
           { traceid_byte_count = { type = "integer", required = true, default = 16, one_of = { 8, 16 } } },
           { header_type = { type = "string", required = true, default = "preserve",
                             one_of = { "preserve", "b3", "b3-single", "w3c" } } },
-          { static_tags = { type = "array", elements = static_tag } }
+          { static_tags = { type = "array", elements = static_tag,
+                            custom_validator = validate_static_tags } }
         },
     }, },
   },
diff --git a/spec/schema_spec.lua b/spec/schema_spec.lua
new file mode 100644
index 0000000..33d7e48
--- /dev/null
+++ b/spec/schema_spec.lua
@@ -0,0 +1,20 @@
+local schema_def = require "kong.plugins.zipkin.schema"
+local v = require("spec.helpers").validate_plugin_config_schema
+
+describe("Plugin: Zipkin (schema)", function()
+  it("rejects repeated tags", function()
+    local ok, err = v({
+      http_endpoint = "http://example.dev",
+      static_tags = {
+        { name = "foo", value = "bar" },
+        { name = "foo", value = "baz" },
+      },
+    }, schema_def)
+
+    assert.is_falsy(ok)
+    assert.same({
+      static_tags = "repeated tags are not allowed: foo"
+    }, err)
+  end)
+end)
+