From 29bdc9d57407c1aa7cb7a8549b0f4e70edf9dd2f Mon Sep 17 00:00:00 2001
From: Victor Woeltjen <victor.woeltjen@nasa.gov>
Date: Fri, 23 Oct 2015 13:04:06 -0700
Subject: [PATCH] [Plot] Ignore empty lines

Ignore empty lines (plot lines with no data) when determining
domain extrema; avoids failure to draw multiple plot lines in
a telemetry panel, nasa/openmctweb#150.
---
 .../features/plot/src/elements/PlotUpdater.js |  4 ++-
 .../plot/test/elements/PlotUpdaterSpec.js     | 32 +++++++++++++++++++
 2 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/platform/features/plot/src/elements/PlotUpdater.js b/platform/features/plot/src/elements/PlotUpdater.js
index d4b4ad3eec9..53cfd1c4c43 100644
--- a/platform/features/plot/src/elements/PlotUpdater.js
+++ b/platform/features/plot/src/elements/PlotUpdater.js
@@ -159,7 +159,9 @@ define(
 
         // Update dimensions and origin based on extrema of plots
         PlotUpdater.prototype.updateBounds = function () {
-            var bufferArray = this.bufferArray,
+            var bufferArray = this.bufferArray.filter(function (lineBuffer) {
+                    return lineBuffer.getLength() > 0; // Ignore empty lines
+                }),
                 priorDomainOrigin = this.origin[0],
                 priorDomainDimensions = this.dimensions[0];
 
diff --git a/platform/features/plot/test/elements/PlotUpdaterSpec.js b/platform/features/plot/test/elements/PlotUpdaterSpec.js
index 9d7ab563dec..c287dbfdf84 100644
--- a/platform/features/plot/test/elements/PlotUpdaterSpec.js
+++ b/platform/features/plot/test/elements/PlotUpdaterSpec.js
@@ -202,6 +202,38 @@ define(
                 expect(updater.getDimensions()[1]).toBeGreaterThan(20);
             });
 
+            describe("when no data is initially available", function () {
+                beforeEach(function () {
+                    testDomainValues = {};
+                    testRangeValues = {};
+                    updater = new PlotUpdater(
+                        mockSubscription,
+                        testDomain,
+                        testRange,
+                        1350 // Smaller max size for easier testing
+                    );
+                });
+
+                it("has no line data", function () {
+                    // Either no lines, or empty lines are fine
+                    expect(updater.getLineBuffers().map(function (lineBuffer) {
+                        return lineBuffer.getLength();
+                    }).reduce(function (a, b) {
+                        return a + b;
+                    }, 0)).toEqual(0);
+                });
+
+                it("determines initial domain bounds from first available data", function () {
+                    testDomainValues.a = 123;
+                    testRangeValues.a = 456;
+                    updater.update();
+                    expect(updater.getOrigin()[0]).toEqual(jasmine.any(Number));
+                    expect(updater.getOrigin()[1]).toEqual(jasmine.any(Number));
+                    expect(isNaN(updater.getOrigin()[0])).toBeFalsy();
+                    expect(isNaN(updater.getOrigin()[1])).toBeFalsy();
+                });
+            });
+
         });
     }
 );