Adding Pattern support for Lists (#20)

* Adding Pattern support for Lists

* Casting to List instead of ArrayList

Author: setchy

README.md

@@ -12,7 +12,7 @@ This library provides extended validation of fields and field arguments for [gra
 # Status
 
 This code is currently under construction.  It is fairly complete in providing powerful validation
-but as it has NOT be consumed by a production like project then its API usefulness has not been tested
+but as it has NOT been consumed by a production like project then its API usefulness has not been tested
 and battle tested. 
 
 But the project welcomes all feedback and input on code design and validation requirements.
@@ -409,7 +409,7 @@ The String must match the specified regular expression, which follows the Java r
 
 - Example : `updateDriver( licencePlate : String @Patttern(regex : "[A-Z][A-Z][A-Z]-[0-9][0-9][0-9]") : DriverDetails`
 
-- Applies to : `String`
+- Applies to : `String`, `Lists`
 
 - SDL : `directive @Pattern(regexp : String! =".*", message : String = "graphql.validation.Pattern.message") on ARGUMENT_DEFINITION | INPUT_FIELD_DEFINITION`
 

src/main/java/graphql/validation/constraints/standard/PatternConstraint.java

@@ -8,12 +8,14 @@
 import graphql.validation.constraints.Documentation;
 import graphql.validation.rules.ValidationEnvironment;
 
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import static graphql.schema.GraphQLTypeUtil.isList;
 import static java.util.Collections.emptyList;
 
 public class PatternConstraint extends AbstractDirectiveConstraint {
@@ -31,9 +33,9 @@ public Documentation getDocumentation() {
 
                 .description("The String must match the specified regular expression, which follows the Java regular expression conventions.")
 
-                .example("updateDriver( licencePlate : String @Patttern(regex : \"[A-Z][A-Z][A-Z]-[0-9][0-9][0-9]\") : DriverDetails")
+                .example("updateDriver( licencePlate : String @Pattern(regexp : \"[A-Z][A-Z][A-Z]-[0-9][0-9][0-9]\") : DriverDetails")
 
-                .applicableTypeNames(Scalars.GraphQLString.getName())
+                .applicableTypeNames(Scalars.GraphQLString.getName(), "Lists")
 
                 .directiveSDL("directive @Pattern(regexp : String! =\".*\", message : String = \"%s\") " +
                                 "on ARGUMENT_DEFINITION | INPUT_FIELD_DEFINITION",
@@ -44,28 +46,39 @@ public Documentation getDocumentation() {
     @Override
     public boolean appliesToType(GraphQLInputType inputType) {
         return isOneOfTheseTypes(inputType,
-                Scalars.GraphQLString
-        );
+            Scalars.GraphQLString) || isList(inputType);
     }
 
     @Override
     protected List<GraphQLError> runConstraint(ValidationEnvironment validationEnvironment) {
         Object validatedValue = validationEnvironment.getValidatedValue();
+        GraphQLInputType argumentType = validationEnvironment.getValidatedType();
+
         if (validatedValue == null) {
             return emptyList();
         }
-        String strValue = String.valueOf(validatedValue);
 
-        GraphQLDirective directive = validationEnvironment.getContextObject(GraphQLDirective.class);
+        List<Object> validatedValues;
+
+        if (isList(argumentType)) {
+            validatedValues = (List)validatedValue;
+        } else {
+            validatedValues = Arrays.asList(validatedValue);
+        }
+
+        for (Object value : validatedValues) {
+            String strValue = String.valueOf(value);
+
+            GraphQLDirective directive = validationEnvironment.getContextObject(GraphQLDirective.class);
 
-        String patternArg = getStrArg(directive, "regexp");
-        Pattern pattern = cachedPattern(patternArg);
+            String patternArg = getStrArg(directive, "regexp");
+            Pattern pattern = cachedPattern(patternArg);
 
-        Matcher matcher = pattern.matcher(strValue);
-        if (!matcher.matches()) {
-            return mkError(validationEnvironment, directive, mkMessageParams(validatedValue, validationEnvironment,
-                    "regexp", patternArg
-            ));
+            Matcher matcher = pattern.matcher(strValue);
+            if (!matcher.matches()) {
+                return mkError(validationEnvironment, directive,
+                    mkMessageParams(validatedValue, validationEnvironment, "regexp", patternArg));
+            }
         }
         return emptyList();
     }

src/test/groovy/graphql/validation/constraints/standard/PatternConstraintTest.groovy

@@ -22,6 +22,8 @@ class PatternConstraintTest extends BaseConstraintTestSupport {
         fieldDeclaration                                       | argVal | expectedMessage
         'field( arg : String @Pattern(regexp:"[A-Z]*") ) : ID' | "ABCd" | 'Pattern;path=/arg;val:ABCd;\t'
         'field( arg : String @Pattern(regexp:"[A-Z]*") ) : ID' | "ABC"  | ''
+        'field( arg : [String] @Pattern(regexp:"[A-Z]*") ) : ID' | ["ABC"]  | ''
+        'field( arg : [String] @Pattern(regexp:"[A-Z]*") ) : ID' | ["ABC", "ABCd"]  | 'Pattern;path=/arg;val:[ABC, ABCd];\t'
 
         // nulls are valid
         'field( arg : String @Pattern(regexp:"[A-Z]*") ) : ID' | null   | ''