fix(zoom): Fix zoom rescale by wheel

Add 'orgXScale' state to be used for re-scale on zooming

Fix #890

.travis.yml

@@ -6,7 +6,6 @@ sudo: false  # no need for virtualization.
 before_install:
   - npm install -g npm@latest
   - npm install -g greenkeeper-lockfile@1
- 	- "curl -H 'Cache-Control: no-cache' https://raw.githubusercontent.com/fossas/fossa-cli/master/install.sh | sudo bash"
 install:
   - npm install
 sudo: required
@@ -21,8 +20,6 @@ before_script:
   - npm run lint
 script:
   - npm run coverage
-  - fossa init
-  - fossa analyze
 after_script:
   - greenkeeper-lockfile-upload
 after_success:

spec/interactions/zoom-spec.js

@@ -225,8 +225,70 @@ describe("ZOOM", function() {
 			chart.unzoom(); // zoom set to initial
 			expect(subX.domain()).to.be.deep.equal(chart.internal.x.orgDomain()); // subX value not updated on zoom in
 		});
+	});
 
-    });
+	describe("zoom wheel", () => {
+		before(() => {
+			args = {
+				size: {
+					width: 300,
+					height: 250
+				},
+				data: {
+					columns: [
+						["data1", 30, 200, 100, 400, 3150, 250],
+						["data2", 50, 20, 10, 40, 15, 6025]
+					]
+				},
+				zoom: {
+					rescale: true,
+					enabled: true
+				}
+			};
+		});
+
+		it("check with rescale option", () => {
+			const eventRect = chart.$.main.select(".bb-event-rect-2").node();
+			const orgDomain = {
+				x: chart.internal.x.domain(),
+				y: chart.internal.y.domain()
+			};
+
+			// when zoom in
+			util.fireEvent(eventRect, "wheel", {
+				deltaX: 0,
+				deltaY: -100,
+				clientX: 159,
+				clientY: 137
+			});
+
+			["x", "y"].forEach(id => {
+				const domain = orgDomain[id];
+
+				expect(
+					chart.internal[id].domain()
+						.every((v, i) => i > 0 ? v < domain[i] : v > domain[i])
+				).to.be.true;
+			});
+
+			// when zoom out
+			util.fireEvent(eventRect, "wheel", {
+				deltaX: 0,
+				deltaY: 100,
+				clientX: 159,
+				clientY: 137
+			});
+
+			["x", "y"].forEach(id => {
+				const domain = orgDomain[id];
+
+				expect(
+					chart.internal[id].domain()
+						.every((v, i) => v === domain[i])
+				).to.be.true;
+			});
+		});
+	});
 
     describe("zoom type drag", () => {
 	    let clickedData;
@@ -359,7 +421,7 @@ describe("ZOOM", function() {
 		    }, chart);
 
 		    expect(clickedData).to.not.be.undefined;
-	    });
+		});
     });
 
 	describe("zoom on regions", () => {
@@ -543,7 +605,7 @@ describe("ZOOM", function() {
 			chart.zoom([new Date("01-01-2016 00:00"), new Date("02-01-2016 00:00")]);
 
 			const expected = ["Jan 03", "Jan 10", "Jan 17", "Jan 24", "Jan 31"];
-			
+
 			chart.$.main.selectAll(selector).each(function(d, i) {
 				expect(this.textContent).to.be.equal(expected[i]);
 			});

src/interactions/zoom.js

@@ -86,8 +86,11 @@ extend(ChartInternal.prototype, {
 		 * @private
 		 */
 		zoom.updateTransformScale = transform => {
+			// in case of resize, update range of orgXScale
+			$$.orgXScale && $$.orgXScale.range($$.x.range());
+
 			// rescale from the original scale
-			const newScale = transform.rescaleX($$.x);
+			const newScale = transform.rescaleX($$.orgXScale || $$.x);
 			const domain = $$.trimXDomain(newScale.domain());
 			const rescale = config.zoom_rescale;
 
@@ -96,7 +99,11 @@ extend(ChartInternal.prototype, {
 			$$.zoomScale = $$.getCustomizedScale(newScale);
 			$$.xAxis.scale($$.zoomScale);
 
-			rescale && $$.x.domain($$.zoomScale.orgDomain());
+			if (rescale) {
+				// copy current initial x scale in case of rescale option is used
+				!$$.orgXScale && ($$.orgXScale = $$.x.copy());
+				$$.x.domain(domain);
+			}
 		};
 
 		$$.zoom = zoom;