implemented \boldsymbol for +

src/buildCommon.js

@@ -120,8 +120,13 @@ const mathsym = function(
     // Have a special case for when the value = \ because the \ is used as a
     // textord in unsupported command errors but cannot be parsed as a regular
     // text ordinal and is therefore not present as a symbol in the symbols
-    // table for text
-    if (value === "\\" || symbols[mode][value].font === "main") {
+    // table for text, as well as a special case for boldsymbol because it
+    // can be used for bold + and -
+    const font = (options && options.font) ? options.font : "";
+    if (utils.contains(boldsymbolLetters, value) && font === "boldsymbol") {
+        return makeSymbol(value, "Main-Bold", mode, options,
+            classes.concat(["mathbf"]));
+    } else if (value === "\\" || symbols[mode][value].font === "main") {
         return makeSymbol(value, "Main-Regular", mode, options, classes);
     } else {
         return makeSymbol(

src/buildMathML.js

@@ -108,10 +108,15 @@ groupTypes.textord = function(group, options) {
     return node;
 };
 
-groupTypes.bin = function(group) {
+groupTypes.bin = function(group, options) {
     const node = new mathMLTree.MathNode(
         "mo", [makeText(group.value, group.mode)]);
 
+    const variant = getVariant(group, options);
+    if (variant === "bold-italic") {
+        node.setAttribute("mathvariant", variant);
+    }
+
     return node;
 };
 

test/__snapshots__/mathml-spec.js.snap

@@ -104,7 +104,7 @@ exports[`A MathML builder should render boldsymbol with the correct mathvariants
         <mi mathvariant="bold-italic">
           ı
         </mi>
-        <mo>
+        <mo mathvariant="bold-italic">
           +
         </mo>
       </mrow>

test/screenshotter/ss_data.yaml

@@ -57,7 +57,7 @@ BinCancellation: |
     \end{array}
 BinomTest: \dbinom{a}{b}\tbinom{a}{b}^{\binom{a}{b}+17}
 BoldSpacing: \mathbf{A}^2+\mathbf{B}_3*\mathscr{C}'
-BoldSymbol: \sum_{\boldsymbol{\alpha}}^{\boldsymbol{\beta}} \boldsymbol{\omega}+ \int_{\boldsymbol{\alpha}}^{\boldsymbol{\beta}} \boldsymbol{\Omega}+\boldsymbol{A}+\boldsymbol{x}
+BoldSymbol: \sum_{\boldsymbol{\alpha}}^{\boldsymbol{\beta}} \boldsymbol{\omega}+ \int_{\boldsymbol{\alpha}}^{\boldsymbol{\beta}} \boldsymbol{\Omega}+\boldsymbol{Ax2k\omega\Omega\imath+}
 Boxed: \boxed{F=ma} \quad \boxed{ac}\color{magenta}{\boxed{F}}\boxed{F=mg}
 Cases: |
     f(a,b)=\begin{cases}