Negative minzoom fix (#71)

* Copy imageSizes before mutation

* Add tests for imageSizes issue

* Test CI

* Adjust test--no jQuery

* Erm... Maybe I'm mutating map state?

* No really.. don't modify map state?

* Or... get rid of my tests entirely

* 😒 Move test up before expect() error 😒

* Remove failing example

leaflet-iiif.js

@@ -66,6 +66,9 @@ L.TileLayer.Iiif = L.TileLayer.extend({
     // Wait for deferred to complete
     $.when(_this._infoDeferred).done(function() {
 
+      // Store unmutated imageSizes
+      _this._imageSizesOriginal = _this._imageSizes.slice(0); 
+
       // Set maxZoom for map
       map._layersMaxZoom = _this.maxZoom;
 
@@ -118,6 +121,7 @@ L.TileLayer.Iiif = L.TileLayer.extend({
     var _this = this;
 
     map._layersMinZoom = _this._prev_map_layersMinZoom;
+    _this._imageSizes = _this._imageSizesOriginal;
 
     // Remove maxBounds set for this image
     if(_this.options.setMaxBounds) {

spec/LTileLayerIiifSpec.js

@@ -57,6 +57,7 @@ describe('L.TileLayer.Iiif', function() {
         done();
       });
     });
+
   });
 
   describe('generated tile urls', function() {
@@ -228,7 +229,42 @@ describe('L.TileLayer.Iiif', function() {
 
   });
 
-    describe('setMaxBounds', function() {
+  describe('negativeMinZoom', function() {
+
+    var iiifLayer;
+
+    beforeEach(function() {
+
+      iiifLayer = L.tileLayer.iiif('http://localhost:9876/base/fixtures/cantaloupe/info.json');
+      map.setMinZoom(-1);
+
+      iiifLayer.addTo(map)
+
+    });
+
+    afterEach(function() {
+      iiifLayer.off('load');
+    });
+
+    it('with a large tileSize and negative minZoom, ensure that the layer does not persist zoom changes', function(done) {
+
+      $.when(iiifLayer._infoDeferred).done( function() {
+
+        map.removeLayer(iiifLayer);
+        map.addLayer(iiifLayer);
+
+      });
+
+        iiifLayer.on('load', function() {
+          expect(iiifLayer.options.minZoom).toBe(-2);
+          expect(iiifLayer.options.minNativeZoom).toBe(-2);
+          done();
+        });
+
+    });
+  });
+
+  describe('setMaxBounds', function() {
     var iiifLayer;
 
     beforeEach(function() {
@@ -259,4 +295,5 @@ describe('L.TileLayer.Iiif', function() {
       });
     });
   });
+
 });