From 5c44c47bd2ca70c2a8585c19d9fae598b1227a57 Mon Sep 17 00:00:00 2001
From: Ron Kok <ronkok@comcast.net>
Date: Sun, 27 Dec 2020 15:29:55 -0800
Subject: [PATCH] =?UTF-8?q?feat:=20Set=20Auto-render=20to=20recognize=20AM?=
 =?UTF-8?q?S=20environments=20without=20$$=E2=80=A6$$=20delimiters.=20(#27?=
 =?UTF-8?q?01)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

* feat: Set Auto-render to recognize AMS environments without $$…$$ delimiters.

* Replace tab with spaces

* Treat AMS environments correctly.
---
 contrib/auto-render/auto-render.js           |  9 ++++++++-
 contrib/auto-render/index.html               | 12 +++++++++---
 contrib/auto-render/splitAtDelimiters.js     | 10 ++++++++--
 contrib/auto-render/test/auto-render-spec.js |  9 +++++++++
 docs/autorender.md                           |  4 ++++
 5 files changed, 38 insertions(+), 6 deletions(-)

diff --git a/contrib/auto-render/auto-render.js b/contrib/auto-render/auto-render.js
index d1c830d1..cf816755 100644
--- a/contrib/auto-render/auto-render.js
+++ b/contrib/auto-render/auto-render.js
@@ -96,7 +96,14 @@ const renderMathInElement = function(elem, options) {
         {left: "\\(", right: "\\)", display: false},
         // LaTeX uses $…$, but it ruins the display of normal `$` in text:
         // {left: "$", right: "$", display: false},
-	// $ must come after $$
+        // $ must come after $$
+
+        // Render AMS environments even if outside $$…$$ delimiters.
+        {left: "\\begin{equation}", right: "\\end{equation}", display: true},
+        {left: "\\begin{align}", right: "\\end{align}", display: true},
+        {left: "\\begin{alignat}", right: "\\end{alignat}", display: true},
+        {left: "\\begin{gather}", right: "\\end{gather}", display: true},
+
         {left: "\\[", right: "\\]", display: true},
     ];
     optionsCopy.ignoredTags = optionsCopy.ignoredTags || [
diff --git a/contrib/auto-render/index.html b/contrib/auto-render/index.html
index 71b49613..d0849b5c 100644
--- a/contrib/auto-render/index.html
+++ b/contrib/auto-render/index.html
@@ -25,13 +25,15 @@
     <div id="test">
       This is some text $math \frac12$ other text $\unsupported$
       <span class="blue">
-        Other node \[ displaymath \frac{1}{2} \] blah $$ \int_2^3 $$
+        Other node \[ \text{displaymath} \frac{1}{2} \] blah $$ \int_2^3 $$
       </span>
       and some <!-- comment --> more text \(and math\) blah. And $math with a
       \$ sign$.
       <pre>
         Stuff in a $pre tag$
       </pre>
+      <p>An AMS environment without <code>$$…$$</code> delimiters.</p>
+      <p>\begin{equation} \begin{split} a &=b+c\\ &=e+f \end{split} \end{equation}</p>
     </div>
     <script>
       renderMathInElement(
@@ -39,9 +41,13 @@
           {
               delimiters: [
                   {left: "$$", right: "$$", display: true},
-                  {left: "\\[", right: "\\]", display: true},
                   {left: "$", right: "$", display: false},
-                  {left: "\\(", right: "\\)", display: false}
+                  {left: "\\begin{equation}", right: "\\end{equation}", display: true},
+                  {left: "\\begin{align}", right: "\\end{align}", display: true},
+                  {left: "\\begin{alignat}", right: "\\end{alignat}", display: true},
+                  {left: "\\begin{gather}", right: "\\end{gather}", display: true},
+                  {left: "\\(", right: "\\)", display: false},
+                  {left: "\\[", right: "\\]", display: true}
               ]
           }
       );
diff --git a/contrib/auto-render/splitAtDelimiters.js b/contrib/auto-render/splitAtDelimiters.js
index b310489c..21b59030 100644
--- a/contrib/auto-render/splitAtDelimiters.js
+++ b/contrib/auto-render/splitAtDelimiters.js
@@ -31,6 +31,8 @@ const escapeRegex = function(string) {
     return string.replace(/[-/\\^$*+?.()|[\]{}]/g, "\\$&");
 };
 
+const amsRegex = /^\\begin{/;
+
 const splitAtDelimiters = function(text, delimiters) {
     let index;
     const data = [];
@@ -57,10 +59,14 @@ const splitAtDelimiters = function(text, delimiters) {
         if (index === -1) {
             break;
         }
+        const rawData = text.slice(0, index + delimiters[i].right.length);
+        const math = amsRegex.test(rawData)
+            ? rawData
+            : text.slice(delimiters[i].left.length, index);
         data.push({
             type: "math",
-            data: text.slice(delimiters[i].left.length, index),
-            rawData: text.slice(0, index + delimiters[i].right.length),
+            data: math,
+            rawData,
             display: delimiters[i].display,
         });
         text = text.slice(index + delimiters[i].right.length);
diff --git a/contrib/auto-render/test/auto-render-spec.js b/contrib/auto-render/test/auto-render-spec.js
index 2665754b..1dc9d856 100644
--- a/contrib/auto-render/test/auto-render-spec.js
+++ b/contrib/auto-render/test/auto-render-spec.js
@@ -97,6 +97,15 @@ describe("A delimiter splitter", function() {
                     rawData: "[[ world ]]", display: false},
                 {type: "text", data: " boo"},
             ]);
+        expect("hello \\begin{equation} world \\end{equation} boo").toSplitInto(
+            "\\begin{equation}", "\\end{equation}",
+            [
+                {type: "text", data: "hello "},
+                {type: "math", data: "\\begin{equation} world \\end{equation}",
+                    rawData: "\\begin{equation} world \\end{equation}",
+                    display: false},
+                {type: "text", data: " boo"},
+            ]);
     });
 
     it("splits mutliple times", function() {
diff --git a/docs/autorender.md b/docs/autorender.md
index 6d6ab620..4df60b89 100644
--- a/docs/autorender.md
+++ b/docs/autorender.md
@@ -84,6 +84,10 @@ in addition to two auto-render-specific keys:
   [
     {left: "$$", right: "$$", display: true},
     {left: "\\(", right: "\\)", display: false},
+    {left: "\\begin{equation}", right: "\\end{equation}", display: true},
+    {left: "\\begin{align}", right: "\\end{align}", display: true},
+    {left: "\\begin{alignat}", right: "\\end{alignat}", display: true},
+    {left: "\\begin{gather}", right: "\\end{gather}", display: true},
     {left: "\\[", right: "\\]", display: true}
   ]
   ```