JS & ArcGIS newb here.
I have a working example (thanks to this forum) that translates from an alternate spatial reference and plots a point on a map. As you can see from the commented out lines below - I am trying to adapt this to plot a path, but I'm not having luck.
<SPAN class="doctype token"><!DOCTYPE html></SPAN>
<SPAN class="token tag"><SPAN class="token tag"><SPAN class="punctuation token"><</SPAN>html</SPAN><SPAN class="punctuation token">></SPAN></SPAN>
<SPAN class="token tag"><SPAN class="token tag"><SPAN class="punctuation token"><</SPAN>head</SPAN><SPAN class="punctuation token">></SPAN></SPAN>
<SPAN class="token tag"><SPAN class="token tag"><SPAN class="punctuation token"><</SPAN>meta</SPAN> <SPAN class="attr-name token">charset</SPAN><SPAN class="attr-value token"><SPAN class="punctuation token">=</SPAN><SPAN class="punctuation token">"</SPAN>utf-8<SPAN class="punctuation token">"</SPAN></SPAN><SPAN class="punctuation token">></SPAN></SPAN>
<SPAN class="token tag"><SPAN class="token tag"><SPAN class="punctuation token"><</SPAN>meta</SPAN> <SPAN class="attr-name token">name</SPAN><SPAN class="attr-value token"><SPAN class="punctuation token">=</SPAN><SPAN class="punctuation token">"</SPAN>viewport<SPAN class="punctuation token">"</SPAN></SPAN> <SPAN class="attr-name token">content</SPAN><SPAN class="attr-value token"><SPAN class="punctuation token">=</SPAN><SPAN class="punctuation token">"</SPAN>initial-scale<SPAN class="punctuation token">=</SPAN>1, maximum-scale<SPAN class="punctuation token">=</SPAN>1, user-scalable<SPAN class="punctuation token">=</SPAN>no<SPAN class="punctuation token">"</SPAN></SPAN><SPAN class="punctuation token">></SPAN></SPAN>
<SPAN class="token tag"><SPAN class="token tag"><SPAN class="punctuation token"><</SPAN>title</SPAN><SPAN class="punctuation token">></SPAN></SPAN>Basic Map<SPAN class="token tag"><SPAN class="token tag"><SPAN class="punctuation token"></</SPAN>title</SPAN><SPAN class="punctuation token">></SPAN></SPAN>
<SPAN class="language-css style token"><SPAN class="token tag"><SPAN class="token tag"><SPAN class="punctuation token"><</SPAN>style</SPAN><SPAN class="punctuation token">></SPAN></SPAN>
<SPAN class="selector token">html, body, #viewDiv</SPAN> <SPAN class="punctuation token">{</SPAN>
<SPAN class="property token">padding</SPAN><SPAN class="punctuation token">:</SPAN> 0<SPAN class="punctuation token">;</SPAN>
<SPAN class="property token">margin</SPAN><SPAN class="punctuation token">:</SPAN> 0<SPAN class="punctuation token">;</SPAN>
<SPAN class="property token">height</SPAN><SPAN class="punctuation token">:</SPAN> 100%<SPAN class="punctuation token">;</SPAN>
<SPAN class="property token">width</SPAN><SPAN class="punctuation token">:</SPAN> 100%<SPAN class="punctuation token">;</SPAN>
<SPAN class="punctuation token">}</SPAN>
<SPAN class="token tag"><SPAN class="token tag"><SPAN class="punctuation token"></</SPAN>style</SPAN><SPAN class="punctuation token">></SPAN></SPAN></SPAN>
<SPAN class="token tag"><SPAN class="token tag"><SPAN class="punctuation token"><</SPAN>link</SPAN> <SPAN class="attr-name token">rel</SPAN><SPAN class="attr-value token"><SPAN class="punctuation token">=</SPAN><SPAN class="punctuation token">"</SPAN>stylesheet<SPAN class="punctuation token">"</SPAN></SPAN> <SPAN class="attr-name token">href</SPAN><SPAN class="attr-value token"><SPAN class="punctuation token">=</SPAN><SPAN class="punctuation token">"</SPAN>https://js.arcgis.com/4.15/esri/themes/light/main.css<SPAN class="punctuation token">"</SPAN></SPAN><SPAN class="punctuation token">></SPAN></SPAN>
<SPAN class="language-javascript script token"><SPAN class="token tag"><SPAN class="token tag"><SPAN class="punctuation token"><</SPAN>script</SPAN> <SPAN class="attr-name token">src</SPAN><SPAN class="attr-value token"><SPAN class="punctuation token">=</SPAN><SPAN class="punctuation token">"</SPAN>https://js.arcgis.com/4.15/<SPAN class="punctuation token">"</SPAN></SPAN><SPAN class="punctuation token">></SPAN></SPAN><SPAN class="token tag"><SPAN class="token tag"><SPAN class="punctuation token"></</SPAN>script</SPAN><SPAN class="punctuation token">></SPAN></SPAN></SPAN>
<SPAN class="language-javascript script token"><SPAN class="token tag"><SPAN class="token tag"><SPAN class="punctuation token"><</SPAN>script</SPAN><SPAN class="punctuation token">></SPAN></SPAN>
<SPAN class="comment token">//Style point</SPAN>
<SPAN class="keyword token">var</SPAN> simpleMarkerSymbol <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">{</SPAN>
type<SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"simple-marker"</SPAN><SPAN class="punctuation token">,</SPAN>
color<SPAN class="punctuation token">:</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="number token">226</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">119</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">40</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="comment token">// orange</SPAN>
outline<SPAN class="punctuation token">:</SPAN> <SPAN class="punctuation token">{</SPAN>
color<SPAN class="punctuation token">:</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="number token">255</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">255</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">255</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="comment token">// white</SPAN>
width<SPAN class="punctuation token">:</SPAN> <SPAN class="number token">1</SPAN>
<SPAN class="punctuation token">}</SPAN>
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="comment token">//style line</SPAN>
<SPAN class="keyword token">var</SPAN> simpleLineSymbol <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">{</SPAN>
type<SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"simple-line"</SPAN><SPAN class="punctuation token">,</SPAN>
color<SPAN class="punctuation token">:</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="number token">226</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">119</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">40</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="comment token">// orange</SPAN>
width<SPAN class="punctuation token">:</SPAN> <SPAN class="number token">2</SPAN>
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="token function">require</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN>
<SPAN class="string token">"esri/Map"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/views/MapView"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/Graphic"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/layers/GraphicsLayer"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/geometry/Point"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/tasks/GeometryService"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/tasks/support/ProjectParameters"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"esri/geometry/SpatialReference"</SPAN>
<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="keyword token">function</SPAN><SPAN class="punctuation token">(</SPAN>Map<SPAN class="punctuation token">,</SPAN> MapView<SPAN class="punctuation token">,</SPAN> Graphic<SPAN class="punctuation token">,</SPAN> GraphicsLayer<SPAN class="punctuation token">,</SPAN> Point<SPAN class="punctuation token">,</SPAN> GeometryService<SPAN class="punctuation token">,</SPAN> ProjectParameters<SPAN class="punctuation token">,</SPAN> SpatialReference<SPAN class="punctuation token">)</SPAN> <SPAN class="punctuation token">{</SPAN>
<SPAN class="keyword token">var</SPAN> sr <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">SpatialReference</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">{</SPAN>
wkid<SPAN class="punctuation token">:</SPAN> <SPAN class="number token">2953</SPAN>
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="keyword token">var</SPAN> map <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">Map</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">{</SPAN>
basemap<SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"topo-vector"</SPAN>
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="keyword token">var</SPAN> graphicsLayer <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">GraphicsLayer</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
map<SPAN class="punctuation token">.</SPAN><SPAN class="token function">add</SPAN><SPAN class="punctuation token">(</SPAN>graphicsLayer<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="keyword token">var</SPAN> point <SPAN class="operator token">=</SPAN> <SPAN class="token function">Point</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">{</SPAN>
type<SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"point"</SPAN><SPAN class="punctuation token">,</SPAN>
x<SPAN class="punctuation token">:</SPAN> <SPAN class="number token">2637779.94</SPAN><SPAN class="punctuation token">,</SPAN>
y<SPAN class="punctuation token">:</SPAN> <SPAN class="number token">7418399.63</SPAN><SPAN class="punctuation token">,</SPAN>
spatialReference<SPAN class="punctuation token">:</SPAN> sr
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="keyword token">var</SPAN> parcelOutline <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">{</SPAN>
type<SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"polyline"</SPAN><SPAN class="punctuation token">,</SPAN>
paths<SPAN class="punctuation token">:</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="number token">2637816.5</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="number token">7418383.95</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="number token">2637788.4</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="number token">7418370.9</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="number token">2637760.75</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="number token">7418357.95</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="number token">2637743.65</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="number token">7418416.45</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="number token">2637799.35</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="number token">7418440.55</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="number token">2637816.5</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="number token">7418383.95</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
spatialReference<SPAN class="punctuation token">:</SPAN> sr
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="keyword token">var</SPAN> geomSer <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">GeometryService</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">{</SPAN>url<SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'https://sampleserver6.arcgisonline.com/arcgis/rest/services/Utilities/Geometry/GeometryServer'</SPAN><SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="keyword token">var</SPAN> params <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">ProjectParameters</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">{</SPAN>
<SPAN class="comment token">//geometries: [point],</SPAN>
geometries<SPAN class="punctuation token">:</SPAN> <SPAN class="punctuation token">[</SPAN>parcelOutline<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
outSpatialReference<SPAN class="punctuation token">:</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">SpatialReference</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">{</SPAN>wkid<SPAN class="punctuation token">:</SPAN><SPAN class="number token">102100</SPAN><SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN>
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
geomSer<SPAN class="punctuation token">.</SPAN><SPAN class="token function">project</SPAN><SPAN class="punctuation token">(</SPAN>params<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="token function">then</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="keyword token">function</SPAN><SPAN class="punctuation token">(</SPAN>results<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">{</SPAN>
<SPAN class="comment token">//var pointGraphic = new Graphic({</SPAN>
<SPAN class="comment token">// geometry: results[0],</SPAN>
<SPAN class="comment token">// symbol: simpleMarkerSymbol</SPAN>
<SPAN class="comment token">//});</SPAN>
<SPAN class="keyword token">var</SPAN> parcelOutlineGraphic <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">Graphic</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">{</SPAN>
geometry<SPAN class="punctuation token">:</SPAN> results<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
symbol<SPAN class="punctuation token">:</SPAN> simpleLineSymbol
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="keyword token">var</SPAN> view <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">MapView</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">{</SPAN>
container<SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"viewDiv"</SPAN><SPAN class="punctuation token">,</SPAN>
map<SPAN class="punctuation token">:</SPAN> map<SPAN class="punctuation token">,</SPAN>
center<SPAN class="punctuation token">:</SPAN> results<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN>
zoom<SPAN class="punctuation token">:</SPAN> <SPAN class="number token">13</SPAN>
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="comment token">//graphicsLayer.add(pointGraphic);</SPAN>
graphicsLayer<SPAN class="punctuation token">.</SPAN><SPAN class="token function">add</SPAN><SPAN class="punctuation token">(</SPAN>parcelOutlineGraphic<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
<SPAN class="token tag"><SPAN class="token tag"><SPAN class="punctuation token"></</SPAN>script</SPAN><SPAN class="punctuation token">></SPAN></SPAN></SPAN>
<SPAN class="token tag"><SPAN class="token tag"><SPAN class="punctuation token"></</SPAN>head</SPAN><SPAN class="punctuation token">></SPAN></SPAN>
<SPAN class="token tag"><SPAN class="token tag"><SPAN class="punctuation token"><</SPAN>body</SPAN><SPAN class="punctuation token">></SPAN></SPAN>
<SPAN class="token tag"><SPAN class="token tag"><SPAN class="punctuation token"><</SPAN>div</SPAN> <SPAN class="attr-name token">id</SPAN><SPAN class="attr-value token"><SPAN class="punctuation token">=</SPAN><SPAN class="punctuation token">"</SPAN>viewDiv<SPAN class="punctuation token">"</SPAN></SPAN><SPAN class="punctuation token">></SPAN></SPAN><SPAN class="token tag"><SPAN class="token tag"><SPAN class="punctuation token"></</SPAN>div</SPAN><SPAN class="punctuation token">></SPAN></SPAN>
<SPAN class="token tag"><SPAN class="token tag"><SPAN class="punctuation token"></</SPAN>body</SPAN><SPAN class="punctuation token">></SPAN></SPAN>
<SPAN class="token tag"><SPAN class="token tag"><SPAN class="punctuation token"></</SPAN>html</SPAN><SPAN class="punctuation token">></SPAN></SPAN><SPAN class="line-numbers-rows"><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN></SPAN>