Merge pull request #1895 from Turfjs/transform-translate-fix

Fix handling of negative distances in transform-translate
Turfjs · May 7, 2020 · 0f97326 · 0f97326
2 parents 26d213d + d8668b9
commit 0f97326
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diff --git a/packages/turf-transform-translate/index.js b/packages/turf-transform-translate/index.js
@@ -47,7 +47,7 @@ function transformTranslate(geojson, distance, direction, options) {
     // Invert with negative distances
     if (distance < 0) {
         distance = -distance;
-        direction = -direction;
+        direction = direction + 180;
     }
 
     // Clone geojson to avoid side effects

diff --git a/packages/turf-transform-translate/test.js b/packages/turf-transform-translate/test.js
@@ -46,6 +46,14 @@ test('translate -- throws', t => {
     t.end();
 });
 
+test('negative distance handling', t => {
+    const result = translate(point([0,0]), 10, 0);
+    const result2 = translate(point([0,0]), -10, 0);
+    t.deepEqual(result, {"type":"Feature","properties":{},"geometry":{"type":"Point","coordinates":[0,0.08993203637245381]}})
+    t.deepEqual(result2, {"type":"Feature","properties":{},"geometry":{"type":"Point","coordinates":[0,-0.08993203637245381]}})
+    t.end()
+})
+
 test('rotate -- mutated input', t => {
     const line = lineString([[10, 10], [12, 15]]);
     const lineBefore = JSON.parse(JSON.stringify(line));