add regression tests

Author: emilykl

test/jasmine/bundle_tests/mathjax_test.js

@@ -159,4 +159,48 @@ describe('Test MathJax v' + mathjaxVersion + ':', function() {
             .then(done, done.fail);
         });
     });
+
+    describe('Test tex rendering:', function() {
+        var gd;
+
+        beforeEach(function() {
+            gd = createGraphDiv();
+        });
+
+        afterEach(destroyGraphDiv);
+
+        it('should hand tex titles and tick labels off to MathJax', function(done) {
+            Plotly.newPlot(gd, {
+                data: [{
+                    x: ['$\\phi$', '$\\nabla \\cdot \\vec{F}$'],
+                    y: [1, 2]
+                }],
+                layout: {
+                    title: { text: '$E = mc^2$' }
+                }
+            })
+            .then(function() {
+                var gd3 = d3Select(gd);
+
+                // '.gtitle-math-group' is only added once MathJax has typeset the
+                // string, so its presence is what tells us the tex was rendered
+                expect(gd3.selectAll('.gtitle-math-group').size()).toBe(1, 'title math group');
+
+                // tick label math groups carry the default 'text-math-group' class
+                expect(gd3.selectAll('.text-math-group').size()).toBe(2, 'tick label math groups');
+
+                var rendered = [];
+                gd3.selectAll('[class*=-math-group]').each(function() {
+                    expect(this.getAttribute('data-math')).toBe('Y');
+                    rendered.push(this.getAttribute('data-unformatted'));
+                });
+                expect(rendered.sort()).toEqual([
+                    '$E = mc^2$',
+                    '$\\nabla \\cdot \\vec{F}$',
+                    '$\\phi$'
+                ]);
+            })
+            .then(done, done.fail);
+        });
+    });
 });

test/jasmine/tests/svg_text_utils_test.js

@@ -1,8 +1,12 @@
 var d3Select = require('../../strict-d3').select;
 var d3SelectAll = require('../../strict-d3').selectAll;
 
+var Plotly = require('../../../lib/index');
 var util = require('../../../src/lib/svg_text_utils');
 
+var createGraphDiv = require('../assets/create_graph_div');
+var destroyGraphDiv = require('../assets/destroy_graph_div');
+
 
 describe('svg+text utils', function() {
     'use strict';
@@ -619,3 +623,40 @@ describe('sanitizeHTML', function() {
         expect(innerHTML).toEqual('<a href="https://example.com/?q=date%20%3E=%202018-01-01">click</a>');
     });
 });
+
+// regression test for https://github.com/plotly/plotly.js/issues/7926
+describe('convertToTspans with an unsupported MathJax version', function() {
+    'use strict';
+
+    var gd;
+    var mathJaxBefore;
+
+    beforeEach(function() {
+        gd = createGraphDiv();
+        mathJaxBefore = window.MathJax;
+        // Fake the presence of MathJax v2 by clearing window.MathJax
+        // and setting window.MathJax.version to a v2.x version string
+        window.MathJax = {version: '2.7.9'};
+    });
+
+    afterEach(function() {
+        if(mathJaxBefore === undefined) delete window.MathJax;
+        else window.MathJax = mathJaxBefore;
+        destroyGraphDiv();
+    });
+
+    it('draws the plot with the tex left unevaluated', function(done) {
+        Plotly.newPlot(gd, [{y: [1, 2, 3]}], {title: {text: '$x^2$'}})
+        .then(function() {
+            // whole plot should render except for tex string
+            expect(d3SelectAll('.scatterlayer .trace').size()).toBe(1, 'trace');
+            expect(d3SelectAll('.xtick').size()).toBeGreaterThan(0, 'x ticks');
+
+            var title = d3Select('.gtitle');
+            expect(title.size()).toBe(1, 'title');
+            expect(title.text()).toBe('$x^2$', 'raw tex as title');
+            expect(title.node().style.display).not.toBe('none', 'title is visible');
+        })
+        .then(done, done.fail);
+    });
+});