factor out legend helper into separate file + add tests

Author: etpinard

src/components/legend/helpers.js

@@ -0,0 +1,25 @@
+/**
+* Copyright 2012-2016, Plotly, Inc.
+* All rights reserved.
+*
+* This source code is licensed under the MIT license found in the
+* LICENSE file in the root directory of this source tree.
+*/
+
+
+'use strict';
+
+var Plots = require('../../plots/plots');
+
+
+exports.legendGetsTrace = function legendGetsTrace(trace) {
+    return trace.visible && Plots.traceIs(trace, 'showLegend');
+};
+
+exports.isGrouped = function isGrouped(legendLayout) {
+    return (legendLayout.traceorder || '').indexOf('grouped') !== -1;
+};
+
+exports.isReversed = function isReversed(legendLayout) {
+    return (legendLayout.traceorder || '').indexOf('reversed') !== -1;
+};

src/components/legend/index.js

@@ -329,22 +329,6 @@ legend.texts = function(context, td, d, i, traces) {
     else text.call(textLayout);
 };
 
-// -----------------------------------------------------
-// legend drawing
-// -----------------------------------------------------
-
-function legendGetsTrace(trace) {
-    return trace.visible && Plots.traceIs(trace, 'showLegend');
-}
-
-function isGrouped(legendLayout) {
-    return (legendLayout.traceorder || '').indexOf('grouped') !== -1;
-}
-
-function isReversed(legendLayout) {
-    return (legendLayout.traceorder || '').indexOf('reversed') !== -1;
-}
-
 legend.getLegendData = function(calcdata, opts) {
 
     // build an { legendgroup: [cd0, cd0], ... } object

test/jasmine/tests/legend_test.js

@@ -1,6 +1,7 @@
 var Legend = require('@src/components/legend');
 var Plots = require('@src/plots/plots');
 
+var helpers = require('@src/components/legend/helpers');
 describe('Test legend:', function() {
     'use strict';
 
@@ -325,4 +326,39 @@ describe('Test legend:', function() {
         });
     });
 
+    describe('legendGetsTraces helper', function() {
+        var legendGetsTrace = helpers.legendGetsTrace;
+
+        it('should return true when trace is visible and supports legend', function() {
+            expect(legendGetsTrace({ visible: true, type: 'bar' })).toBe(true);
+            expect(legendGetsTrace({ visible: false, type: 'bar' })).toBe(false);
+            expect(legendGetsTrace({ visible: true, type: 'contour' })).toBe(false);
+            expect(legendGetsTrace({ visible: false, type: 'contour' })).toBe(false);
+        });
+    });
+
+    describe('isGrouped helper', function() {
+        var isGrouped = helpers.isGrouped;
+
+        it('should return true when trace is visible and supports legend', function() {
+            expect(isGrouped({ traceorder: 'normal' })).toBe(false);
+            expect(isGrouped({ traceorder: 'grouped' })).toBe(true);
+            expect(isGrouped({ traceorder: 'reversed+grouped' })).toBe(true);
+            expect(isGrouped({ traceorder: 'grouped+reversed' })).toBe(true);
+            expect(isGrouped({ traceorder: 'reversed' })).toBe(false);
+        });
+    });
+
+    describe('isReversed helper', function() {
+        var isReversed = helpers.isReversed;
+
+        it('should return true when trace is visible and supports legend', function() {
+            expect(isReversed({ traceorder: 'normal' })).toBe(false);
+            expect(isReversed({ traceorder: 'grouped' })).toBe(false);
+            expect(isReversed({ traceorder: 'reversed+grouped' })).toBe(true);
+            expect(isReversed({ traceorder: 'grouped+reversed' })).toBe(true);
+            expect(isReversed({ traceorder: 'reversed' })).toBe(true);
+        });
+    });
+
 });