Adding Lists support for @NotBlank validation directive

README.md

@@ -389,7 +389,7 @@ The String must contain at least one non-whitespace character, according to Java
 
 - Example : `updateAccident( accidentNotes : String @NotBlank) : DriverDetails`
 
-- Applies to : `String`, `ID`
+- Applies to : `String`, `ID`, `Lists`
 
 - SDL : `directive @NotBlank(message : String = "graphql.validation.NotBlank.message") on ARGUMENT_DEFINITION | INPUT_FIELD_DEFINITION`
 

src/main/java/graphql/validation/constraints/AbstractDirectiveConstraint.java

@@ -307,6 +307,18 @@ protected List<GraphQLError> mkError(ValidationEnvironment validationEnvironment
         return singletonList(error);
     }
 
+    /**
+     * Return true if the type is a String or ID or List type, regardless of non null ness
+     *
+     * @param inputType the type to check
+     *
+     * @return true if one of the above
+     */
+    protected boolean isStringOrIDOrList(GraphQLInputType inputType) {
+        return isStringOrID(inputType) ||
+            isList(inputType);
+    }
+
     /**
      * Return true if the type is a String or ID or List type or {@link graphql.schema.GraphQLInputObjectType}, regardless of non null ness
      *

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

@@ -1,5 +1,7 @@
 package graphql.validation.constraints.standard;
 
+import static graphql.schema.GraphQLTypeUtil.isList;
+
 import graphql.GraphQLError;
 import graphql.Scalars;
 import graphql.schema.GraphQLDirective;
@@ -8,6 +10,7 @@
 import graphql.validation.constraints.Documentation;
 import graphql.validation.rules.ValidationEnvironment;
 
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
@@ -26,7 +29,7 @@ public Documentation getDocumentation() {
 
                 .example("updateAccident( accidentNotes : String @NotBlank) : DriverDetails")
 
-                .applicableTypeNames(Scalars.GraphQLString.getName(), Scalars.GraphQLID.getName())
+                .applicableTypeNames(Scalars.GraphQLString.getName(), Scalars.GraphQLID.getName(), "Lists")
 
                 .directiveSDL("directive @NotBlank(message : String = \"%s\") " +
                                 "on ARGUMENT_DEFINITION | INPUT_FIELD_DEFINITION",
@@ -36,19 +39,38 @@ public Documentation getDocumentation() {
 
     @Override
     public boolean appliesToType(GraphQLInputType inputType) {
-        return isStringOrID(inputType);
+        return isStringOrIDOrList(inputType);
     }
 
     @Override
     protected List<GraphQLError> runConstraint(ValidationEnvironment validationEnvironment) {
         Object validatedValue = validationEnvironment.getValidatedValue();
+        GraphQLInputType argumentType = validationEnvironment.getValidatedType();
 
         GraphQLDirective directive = validationEnvironment.getContextObject(GraphQLDirective.class);
 
-        if (validatedValue == null || isBlank(validatedValue)) {
+        if (validatedValue == null) {
+            return mkError(validationEnvironment, directive, mkMessageParams(validatedValue, validationEnvironment));
+        }
+
+        List<Object> validatedValues;
+
+        if (isList(argumentType)) {
+            validatedValues = (List)validatedValue;
+        } else {
+            validatedValues = Arrays.asList(validatedValue);
+        }
+
+        if (validatedValues.size() <= 0) {
             return mkError(validationEnvironment, directive, mkMessageParams(validatedValue, validationEnvironment));
+        }
 
+        for (Object value : validatedValues) {
+            if (isBlank(value)) {
+                return mkError(validationEnvironment, directive, mkMessageParams(validatedValue, validationEnvironment));
+            }
         }
+
         return Collections.emptyList();
     }
 

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

@@ -31,6 +31,18 @@ class NoEmptyBlankConstraintTest extends BaseConstraintTestSupport {
         'field( arg : ID @NotBlank ) : ID' | ""         | 'NotBlank;path=/arg;val:;\t'
         'field( arg : ID @NotBlank ) : ID' | "\t\n\r X" | ''
         'field( arg : ID @NotBlank ) : ID' | null       | ''
+
+        // Lists
+        'field( arg : [String] @NotBlank ) : ID'    | []          | 'NotBlank;path=/arg;val:[];\t'
+        'field( arg : [String] @NotBlank ) : ID'    | null        | ''
+        'field( arg : [String] @NotBlank ) : ID'    | ["x"]       | ''
+        'field( arg : [String] @NotBlank ) : ID'    | ["x", "y"]  | ''
+        'field( arg : [String] @NotBlank ) : ID'    | ["x", "  "] | 'NotBlank;path=/arg;val:[x,   ];\t'
+        'field( arg : [ID] @NotBlank ) : ID'        | []          | 'NotBlank;path=/arg;val:[];\t'
+        'field( arg : [ID] @NotBlank ) : ID'        | null        | ''
+        'field( arg : [ID] @NotBlank ) : ID'        | ["x"]       | ''
+        'field( arg : [ID] @NotBlank ) : ID'        | ["x", "y"]  | ''
+        'field( arg : [String] @NotBlank ) : ID'    | ["x", "  "] | 'NotBlank;path=/arg;val:[x,   ];\t'
     }
 
     @Unroll