Merge pull request Turfjs#389 from Turfjs/line-snap

better tests for turf-point-on-line

.gitignore

@@ -12,6 +12,6 @@ pids
 logs
 results
 
-npm-debug.log
+npm-debug.log*
 
 node_modules

packages/turf-point-on-line/package.json

@@ -4,7 +4,7 @@
   "description": "",
   "main": "index.js",
   "scripts": {
-    "test": "node test.js"
+    "test": "node test/test.js"
   },
   "repository": {
     "type": "git",
@@ -19,7 +19,10 @@
   "devDependencies": {
     "benchmark": "^1.0.0",
     "tape": "^3.5.0",
-    "turf-helpers": "^3.0.5"
+    "turf-along": "^3.0.5",
+    "turf-distance": "^3.0.5",
+    "turf-helpers": "^3.0.5",
+    "turf-line-distance": "^3.0.5"
   },
   "dependencies": {
     "turf-bearing": "^3.0.1",

packages/turf-point-on-line/test/test.js

@@ -0,0 +1,122 @@
+var test = require('tape');
+var pointOnLine = require('../');
+var point = require('turf-helpers').point;
+var featurecollection = require('turf-helpers').featureCollection;
+var linestring = require('turf-helpers').lineString;
+var distance = require('turf-distance');
+var lineDistance = require('turf-line-distance');
+var along = require('turf-along');
+
+test('turf-point-on-line - first point', function (t) {
+    var line = linestring([[-122.45717525482178,37.72003306385638],[-122.45717525482178,37.718242366859215]]);
+    var pt = point([-122.45717525482178,37.72003306385638]);
+
+    var snapped = pointOnLine(line, pt);
+
+    t.deepEqual(pt.geometry.coordinates, snapped.geometry.coordinates, 'pt on start does not move');
+
+    t.end();
+});
+
+test('turf-point-on-line - points behind first point', function (t) {
+    var line = linestring([[-122.45717525482178,37.72003306385638],[-122.45717525482178,37.718242366859215]]);
+    var first = point(line.geometry.coordinates[0])
+    var pts = [
+        point([-122.45717525482178,37.72009306385638]),
+        point([-122.45717525482178,37.82009306385638]),
+        point([-122.45716525482178,37.72009306385638]),
+        point([-122.45516525482178,37.72009306385638])
+    ];
+
+    pts.forEach(function(pt){
+        var snapped = pointOnLine(line, pt);
+        t.deepEqual(first.geometry.coordinates, snapped.geometry.coordinates, 'pt behind start moves to first vertex');
+    });
+
+    t.end();
+});
+
+test('turf-point-on-line - points in front of last point', function (t) {
+    var line = linestring([[-122.45616137981413,37.72125936929241],[-122.45717525482178,37.72003306385638],[-122.45717525482178,37.718242366859215]]);
+    var last = point(line.geometry.coordinates[line.geometry.coordinates.length - 1])
+    var pts = [
+        point([-122.45696067810057,37.71814052497085]),
+        point([-122.4573630094528,37.71813203814049]),
+        point([-122.45730936527252,37.71797927502795]),
+        point([-122.45718061923981,37.71704571582896])
+    ];
+
+    pts.forEach(function(pt){
+        var snapped = pointOnLine(line, pt);
+        t.deepEqual(last.geometry.coordinates, snapped.geometry.coordinates, 'pt behind start moves to last vertex');
+    });
+
+    t.end();
+});
+
+test('turf-point-on-line - points on joints', function (t) {
+    var lines = [
+        linestring([[-122.45616137981413,37.72125936929241],[-122.45717525482178,37.72003306385638],[-122.45717525482178,37.718242366859215]]),
+        linestring([[26.279296875,31.728167146023935],[21.796875,32.69486597787505],[18.80859375,29.99300228455108],[12.919921874999998,33.137551192346145],[10.1953125,35.60371874069731],[4.921875,36.527294814546245],[-1.669921875,36.527294814546245],[-5.44921875,34.74161249883172],[-8.7890625,32.99023555965106]]),
+        linestring([[-0.10919809341430663,51.52204224896724],[-0.10923027992248535,51.521942114455435],[-0.10916590690612793,51.52186200668747],[-0.10904788970947266,51.52177522311313],[-0.10886549949645996,51.521601655468345],[-0.10874748229980469,51.52138135712038],[-0.10855436325073242,51.5206870765674],[-0.10843634605407713,51.52027984939518],[-0.10839343070983887,51.519952729849024],[-0.10817885398864746,51.51957887606202],[-0.10814666748046874,51.51928513164789],[-0.10789990425109863,51.518624199789016],[-0.10759949684143065,51.51778299991493]])
+    ];
+
+    lines.forEach(function(line){
+        line.geometry.coordinates.map(function(coord){
+            return point(coord);
+        }).forEach(function(pt){
+            var snapped = pointOnLine(line, pt);
+            t.deepEqual(pt.geometry.coordinates, snapped.geometry.coordinates, 'pt on joint stayed in place');
+        });
+    });
+
+    t.end();
+});
+
+test('turf-point-on-line - points on top of line', function (t) {
+    var line = linestring([[-0.10919809341430663,51.52204224896724],[-0.10923027992248535,51.521942114455435],[-0.10916590690612793,51.52186200668747],[-0.10904788970947266,51.52177522311313],[-0.10886549949645996,51.521601655468345],[-0.10874748229980469,51.52138135712038],[-0.10855436325073242,51.5206870765674],[-0.10843634605407713,51.52027984939518],[-0.10839343070983887,51.519952729849024],[-0.10817885398864746,51.51957887606202],[-0.10814666748046874,51.51928513164789],[-0.10789990425109863,51.518624199789016],[-0.10759949684143065,51.51778299991493]]);
+
+    var dist = lineDistance(line, 'miles');
+    var increment = dist / 10;
+
+    for (var i = 0; i < 10; i++) {
+        var pt = along(line, increment * i, 'miles');
+        var snapped = pointOnLine(line, pt);
+        var shift = distance(pt, snapped, 'miles');
+        t.true(shift < 0.000001, 'pt did not shift far');    
+    }
+
+    t.end();
+});
+
+test('turf-point-on-line - point along line', function (t) {
+    var line = linestring([[-122.45717525482178,37.72003306385638],[-122.45717525482178,37.718242366859215]]);
+
+    var pt = along(line, 0.019, 'miles');
+    var snapped = pointOnLine(line, pt);
+    var shift = distance(pt, snapped, 'miles');
+
+    t.true(shift < 0.00001, 'pt did not shift far');    
+
+    t.end();
+});
+
+test('turf-point-on-line - points on sides of lines', function (t) {
+    var line = linestring([[-122.45616137981413,37.72125936929241],[-122.45717525482178,37.718242366859215]]);
+    var first = line.geometry.coordinates[0];
+    var last = line.geometry.coordinates[line.geometry.coordinates.length - 1];
+    var pts = [
+        point([-122.45702505111694,37.71881098149625]),
+        point([-122.45733618736267,37.719235317933844]),
+        point([-122.45686411857605,37.72027068864082]),
+        point([-122.45652079582213,37.72063561093274])
+    ];
+
+    pts.forEach(function(pt){
+        var snapped = pointOnLine(line, pt);
+        t.notDeepEqual(snapped.geometry.coordinates, first, 'pt did not snap to first vertex');
+        t.notDeepEqual(snapped.geometry.coordinates, last, 'pt did not snap to last vertex');
+    });
+
+    t.end();
+});