Fix a validation bug in put synonym rule

Author: carlosdelest

rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/synonyms/50_synonym_rule_put.yml

@@ -79,3 +79,69 @@ setup:
         rule_id: "test-id-0"
         body:
           synonyms: "i-phone, iphone"
+
+---
+"Timeout can be specified":
+  - do:
+      synonyms.put_synonym_rule:
+        set_id: "test-synonyms"
+        rule_id: "test-id-0"
+        timeout: 10s
+        body:
+          synonyms: "i-phone, iphone"
+
+  - match: { result: "created" }
+  - match: { reload_analyzers_details._shards.total: 0 }
+  - length: { reload_analyzers_details.reload_details: 0 }
+
+---
+"Validation failure tests":
+  - do:
+      catch: /\[synonyms\] field can't be empty/
+      synonyms.put_synonym_rule:
+        set_id: "test-synonyms"
+        rule_id: "test-id-0"
+        body:
+          synonyms: ""
+
+  - do:
+      catch: /More than one explicit mapping specified in the same synonyms rule/
+      synonyms.put_synonym_rule:
+        set_id: "test-synonyms"
+        rule_id: "test-id-0"
+        body:
+          synonyms: "bye => => goodbye"
+
+  - do:
+      catch: /Incorrect syntax for \[synonyms\]/
+      synonyms.put_synonym_rule:
+        set_id: "test-synonyms"
+        rule_id: "test-id-0"
+        body:
+          synonyms: " => goodbye"
+
+  - do:
+      catch: /Incorrect syntax for \[synonyms\]/
+      synonyms.put_synonym_rule:
+        set_id: "test-synonyms"
+        rule_id: "test-id-0"
+        body:
+          synonyms: "bye => "
+
+  - do:
+      catch: /Incorrect syntax for \[synonyms\]/
+      synonyms.put_synonym_rule:
+        set_id: "test-synonyms"
+        rule_id: "test-id-0"
+        body:
+          synonyms: "bye, goodbye,  "
+
+  - do:
+      catch: /as a time value:\ negative durations are not supported/
+      synonyms.put_synonym_rule:
+        set_id: "test-synonyms"
+        rule_id: "test-id-0"
+        timeout: -100s
+        body:
+          synonyms_set:
+            - synonyms: "bye, goodbye"

server/src/main/java/org/elasticsearch/action/synonyms/PutSynonymRuleAction.java

@@ -97,6 +97,10 @@ public ActionRequestValidationException validate() {
             if (Strings.isNullOrEmpty(synonymRule.id())) {
                 validationException = ValidateActions.addValidationError("synonym rule id must be specified", validationException);
             }
+            String error = synonymRule.validate();
+            if (error != null) {
+                validationException = ValidateActions.addValidationError(error, validationException);
+            }
 
             return validationException;
         }