Support island input from libpostal

This includes an edge case for Hawaii to handle islands which are mostly
stored as counties in our data currently. See https://github.com/pelias/whosonfirst/issues/94.

query/text_parser.js

@@ -39,6 +39,12 @@ function addParsedVariablesToQueryVariables( parsed_text, vs ){
     vs.var( 'input:postcode', parsed_text.postalcode );
   }
 
+
+  // island
+  if( parsed_text.hasOwnProperty('island') ){
+    vs.var( 'input:island', parsed_text.island );
+  }
+
   // ==== add parsed matches [admin components] ====
 
   // city
@@ -83,6 +89,11 @@ function addParsedVariablesToQueryVariables( parsed_text, vs ){
     vs.unset( 'input:query' );
   }
 
+
+  if (shouldTreatIslandAsCounty(vs)) {
+    vs.var( 'input:county', vs.var('input:island').toString());
+    vs.unset('input:island');
+  }
 }
 
 function shouldSetQueryIntoHouseNumber(vs) {
@@ -91,4 +102,11 @@ function shouldSetQueryIntoHouseNumber(vs) {
           /^[0-9]+$/.test(vs.var('input:query').toString());
 }
 
+function shouldTreatIslandAsCounty(vs) {
+  return vs.isset('input:island') &&
+    vs.isset('input:region') &&
+    !vs.isset('input:county') &&
+    vs.var('input:region').toString() === 'hawaii';
+}
+
 module.exports = addParsedVariablesToQueryVariables;

test/unit/query/text_parser.js

@@ -154,6 +154,37 @@ module.exports.tests.housenumber_special_cases = function(test, common) {
 
 };
 
+module.exports.tests.islands = function(test, common) {
+  test('island normally left untouched', function(t) {
+    var parsed_text = {
+      island: 'an island',
+      state: 'somewhere'
+    };
+    var vs = new VariableStore();
+
+    text_parser(parsed_text, vs);
+
+    t.equals(vs.var('input:island').toString(), 'an island');
+    t.equals(vs.var('input:region').toString(), 'somewhere');
+    t.end();
+  });
+
+  test('islands in hawaii should have island changed to county', function(t) {
+    var parsed_text = {
+      island: 'maui',
+      state: 'hawaii'
+    };
+    var vs = new VariableStore();
+
+    text_parser(parsed_text, vs);
+
+    t.equals(vs.var('input:county').toString(), 'maui');
+    t.false(vs.isset('input:island'));
+    t.equals(vs.var('input:region').toString(), 'hawaii');
+    t.end();
+  });
+};
+
 module.exports.all = function (tape, common) {
   function test(name, testFunction) {
     return tape('text_parser ' + name, testFunction);