feat(async): async-ify analyze.street()

.jshintrc

@@ -2,7 +2,7 @@
   "node": true,
   "curly": true,
   "eqeqeq": true,
-  "esversion": 6,
+  "esversion": 8,
   "freeze": true,
   "immed": true,
   "indent": 2,

api/extract.js

@@ -1,6 +1,7 @@
 const Database = require('better-sqlite3');
 const query = { extract: require('../query/extract') };
 const analyze = require('../lib/analyze');
+const asyncForEach = require('../lib/asyncForEach');
 
 // export setup method
 function setup( addressDbPath, streetDbPath ){
@@ -12,16 +13,16 @@ function setup( addressDbPath, streetDbPath ){
   db.exec(`ATTACH DATABASE '${streetDbPath}' as 'street'`);
 
   // query method
-  var q = function( coord, names, cb ){
+  var q = async function( coord, names, cb ){
 
     var point = {
       lat: parseFloat( coord.lat ),
       lon: parseFloat( coord.lon )
     };
 
     var normalized = [];
-    names.forEach( function( name ){
-      normalized = normalized.concat( analyze.street( name ) );
+    await asyncForEach(names, async (name) => {
+      normalized = normalized.concat( await analyze.street( name ) );
     });
 
     // error checking

api/search.js

@@ -19,7 +19,7 @@ function setup( addressDbPath, streetDbPath ){
   db.exec('PRAGMA street.mmap_size=268435456;');
 
   // query method
-  var q = function( coord, number, street, cb ){
+  var q = async function( coord, number, street, cb ){
 
     var point = {
       lat: parseFloat( coord.lat ),
@@ -31,7 +31,7 @@ function setup( addressDbPath, streetDbPath ){
 
     var normalized = {
       number: analyze.housenumber( number ),
-      street: analyze.street( street )
+      street: await analyze.street( street )
     };
 
     // error checking

cmd/server.js

@@ -217,10 +217,10 @@ app.use('/demo', express.static('demo'));
 // app.use('/builds', express.static('/data/builds'));
 // app.use('/builds', directory('/data/builds', { hidden: false, icons: false, view: 'details' }));
 
-app.listen( PORT, function() {
+app.listen( PORT, async function() {
 
   // force loading of libpostal
-  analyze.street( 'test street' );
+  await analyze.street( 'test street' );
 
   console.log( 'server listening on port', PORT );
 });

lib/analyze.js

@@ -31,11 +31,11 @@ function get_libpostal() {
 /**
   analyze input streetname string and return a list of expansions.
 **/
-function street( streetName ){
+async function street( streetName ){
   const postal = get_libpostal();
 
   // use libpostal to expand the address
-  var expansions = postal.expand.expand_address( streetName );
+  let expansions = await postal.expand.expand_address( streetName );
 
   // remove ordinals
   expansions = expansions.map(function( item ){

lib/asyncForEach.js

@@ -0,0 +1,8 @@
+// async friendly version of Array.forEach
+async function asyncForEach(array, callback) {
+  for (let index = 0; index < array.length; index++) {
+    await callback(array[index], index, array);
+  }
+}
+
+module.exports = asyncForEach;

stream/address/lookup.js

@@ -17,7 +17,7 @@ if( hasFD3 ){
 
 function streamFactory(db){
 
-  return through.obj(function( batch, _, next ){
+  return through.obj(async function( batch, _, next ){
 
     // invalid batch
     if( !batch || !batch.length ){
@@ -30,7 +30,7 @@ function streamFactory(db){
 
     // all street names in batch should be the same
     // perform libpostal normalization
-    var names = analyze.street( result.getStreet() );
+    var names = await analyze.street( result.getStreet() );
 
     // ensure at least one name was produced
     if( !names.length ){

stream/street/augment.js

@@ -1,5 +1,6 @@
 const through = require('through2');
 const analyze = require('../../lib/analyze');
+const asyncForEach = require('../../lib/asyncForEach');
 
 // increase/decrease bbox bounds by this much in order to find houses which
 // might be slighly outside the bounds.
@@ -15,12 +16,12 @@ const FUDGE_FACTOR = 0.005;
 **/
 
 // the transform function is executed once per batch in the stream.
-const transform = (street, _, next) => {
+const transform = async (street, _, next) => {
 
   // normalize all names
   let names = [];
-  street.getNames().forEach(function (name) {
-    names = names.concat(analyze.street(name));
+  await asyncForEach(street.getNames(), async (name) => {
+    names = names.concat(await analyze.street(name));
   });
 
   // if the source file contains no valid names for this polyline

test/lib/analyze.js

@@ -4,18 +4,18 @@ var analyze = require('../../lib/analyze');
 module.exports.analyze = {};
 
 module.exports.analyze.street = function(test) {
-  test('street: synonym expansions', function(t) {
-    var perms = analyze.street('grolmanstraße');
+  test('street: synonym expansions', async function(t) {
+    var perms = await analyze.street('grolmanstraße');
     t.deepEqual(perms, ['grolmanstraße', 'grolman straße']);
     t.end();
   });
-  test('street: remove ordinals', function(t) {
-    var perms = analyze.street('West 26th st');
+  test('street: remove ordinals', async function(t) {
+    var perms = await analyze.street('West 26th st');
     t.deepEqual(perms, ['west 26 street', 'west 26 saint']);
     t.end();
   });
-  test('street: always returns array', function(t) {
-    var perms = analyze.street('');
+  test('street: always returns array', async function(t) {
+    var perms = await analyze.street('');
     t.deepEqual(perms, ['']);
     t.end();
   });