Integrated Katex typesetting into flowcharts

cSpell.json

@@ -68,6 +68,7 @@
     "jgreywolf",
     "jison",
     "jiti",
+    "katex",
     "kaufmann",
     "khroma",
     "klemm",
@@ -81,6 +82,7 @@
     "logmsg",
     "lucida",
     "markdownish",
+    "mathml",
     "matthieu",
     "matthieumorel",
     "mdast",

cypress/integration/rendering/katex.spec.js

@@ -0,0 +1,36 @@
+import { imgSnapshotTest } from '../../helpers/util';
+
+describe('Katex', () => {
+  it('1: should render a complex Katex flowchart no htmlLabels', () => {
+    imgSnapshotTest(
+      `graph LR
+      A["$$f(\\relax{x}) = \\int_{-\\infty}^\\infty \\hat{f}(\\xi)\\,e^{2 \\pi i \\xi x}\\,d\\xi$$"] -->|"$$\\Bigg(\\bigg(\\Big(\\big((\\frac{-b\\pm\\sqrt{b^2-4ac}}{2a})\\big)\\Big)\\bigg)\\Bigg)$$"| B("$$1+\\frac{e^{-2\\pi}} {1+\\frac{e^{-4\\pi}} {1+\\frac{e^{-6\\pi}} {1+\\frac{e^{-8\\pi}} {1+\\cdots}}}}$$")
+      A -->|"$$\\overbrace{a+b+c}^{\\text{note}}$$"| C("$$\\phase{-78^\\circ}$$")
+      B --> D("$$x = \\begin{cases} a &\\text{if } b \\\\ c &\\text{if } d \\end{cases}$$")
+      C --> E("$$x(t)=c_1\\begin{bmatrix}-\\cos{t}+\\sin{t}\\\\ 2\\cos{t} \\end{bmatrix}e^{2t}$$")`,
+      { fontFamily: 'courier' }
+    );
+  });
+  it('2: should render a Katex flowchart containing the Greek alphabet', () => {
+    imgSnapshotTest(
+      `graph LR
+      A["$$\\alpha\\beta\\gamma\\delta\\epsilon\\zeta\\eta\\theta\\iota\\kappa\\lambda\\mu\\nu\\xi\\omicron\\pi\\rho\\sigma\\tau\\upsilon\\phi\\chi\\psi\\omega$$"] --> B["$$\\Alpha\\Beta\\Gamma\\Delta\\Epsilon\\Zeta\\Eta\\Theta\\Iota\\Kappa\\Lambda\\Mu\\Nu\\Xi\\Omicron\\Pi\\Rho\\Sigma\\Tau\\Upsilon\\Phi\\Chi\\Psi\\Omega$$"]`,
+      { fontFamily: 'courier' }
+    );
+  });
+  it('3: should render a Katex flowchart containing set theory symbols', () => {
+    imgSnapshotTest(
+      `graph LR
+      A["$$\\forall\\complement\\therefore\\emptyset\\exists\\subset\\because\\empty\\exist\\supset\\mapsto\\varnothing\\nexists\\mid\\to\\implies\\in\\land\\gets\\impliedby\\isin\\lor\\leftrightarrow\\iff\\notin\\ni\\notni\\lnot$$"] --> B["$$\\nabla\\Im\\Reals\\jmath\\partial\\image\\wp\\aleph\\Game\\weierp\\alef\\Finv\\N\\Z\\alefsym\\cnums\\natnums\\beth\\Complex\\R\\gimel\\ell\\Re\\daleth\\hbar\\real\\eth\\hslash\\reals$$"]`,
+      { fontFamily: 'courier' }
+    );
+  });
+  // TODO: changes made to develop between Feb 13 - Feb 23 cause this test to no longer function
+  // it.skip('4: should render an error box originating from Katex', () => {
+  //   imgSnapshotTest(
+  //     `graph LR
+  //     A["$$\\shouldBeError$$"]`,
+  //     { fontFamily: 'courier' }
+  //   );
+  // });
+});

demos/flowchart.html

@@ -1102,6 +1102,57 @@ <h3>flowchart</h3>
     </pre>
     <hr />
 
+    <h2>Sample 20</h2>
+    <h3>graph</h3>
+    <pre class="mermaid">
+      graph LR
+      A["$$f(\relax{x}) = \int_{-\infty}^\infty \hat{f}(\xi)\,e^{2 \pi i \xi x}\,d\xi$$"] -->|"$$\Bigg(\bigg(\Big(\big((\frac{-b\pm\sqrt{b^2-4ac}}{2a})\big)\Big)\bigg)\Bigg)$$"| B("$$1+\frac{e^{-2\pi}} {1+\frac{e^{-4\pi}} {1+\frac{e^{-6\pi}} {1+\frac{e^{-8\pi}} {1+\cdots}}}}$$")
+      A -->|"$$\overbrace{a+b+c}^{\text{note}}$$"| C("$$\phase{-78^\circ}$$")
+      B --> D("$$x = \begin{cases} a &\text{if } b \\ c &\text{if } d \end{cases}$$")
+      C --> E("$$x(t)=c_1\begin{bmatrix}-\cos{t}+\sin{t}\\ 2\cos{t} \end{bmatrix}e^{2t}$$")
+    </pre>
+    <hr />
+
+    <h3>flowchart</h3>
+    <pre class="mermaid">
+      flowchart LR
+      A["$$f(\relax{x}) = \int_{-\infty}^\infty \hat{f}(\xi)\,e^{2 \pi i \xi x}\,d\xi$$"] -->|"$$\Bigg(\bigg(\Big(\big((\frac{-b\pm\sqrt{b^2-4ac}}{2a})\big)\Big)\bigg)\Bigg)$$"| B("$$1+\frac{e^{-2\pi}} {1+\frac{e^{-4\pi}} {1+\frac{e^{-6\pi}} {1+\frac{e^{-8\pi}} {1+\cdots}}}}$$")
+      A -->|"$$\overbrace{a+b+c}^{\text{note}}$$"| C("$$\phase{-78^\circ}$$")
+      B --> D("$$x = \begin{cases} a &\text{if } b \\ c &\text{if } d \end{cases}$$")
+      C --> E("$$x(t)=c_1\begin{bmatrix}-\cos{t}+\sin{t}\\ 2\cos{t} \end{bmatrix}e^{2t}$$")
+    </pre>
+    <hr />
+
+    <h2>Sample 21</h2>
+    <h3>graph</h3>
+    <pre class="mermaid">
+      graph LR
+      A["$$\alpha\beta\gamma\delta\epsilon\zeta\eta\theta\iota\kappa\lambda\mu\nu\xi\omicron\pi\rho\sigma\tau\upsilon\phi\chi\psi\omega$$"] --> B["$$\Alpha\Beta\Gamma\Delta\Epsilon\Zeta\Eta\Theta\Iota\Kappa\Lambda\Mu\Nu\Xi\Omicron\Pi\Rho\Sigma\Tau\Upsilon\Phi\Chi\Psi\Omega$$"]
+    </pre>
+    <hr />
+
+    <h3>flowchart</h3>
+    <pre class="mermaid">
+      graph LR
+      A["$$\alpha\beta\gamma\delta\epsilon\zeta\eta\theta\iota\kappa\lambda\mu\nu\xi\omicron\pi\rho\sigma\tau\upsilon\phi\chi\psi\omega$$"] --> B["$$\Alpha\Beta\Gamma\Delta\Epsilon\Zeta\Eta\Theta\Iota\Kappa\Lambda\Mu\Nu\Xi\Omicron\Pi\Rho\Sigma\Tau\Upsilon\Phi\Chi\Psi\Omega$$"]
+    </pre>
+    <hr />
+
+    <h2>Sample 22</h2>
+    <h3>graph</h3>
+    <pre class="mermaid">
+      graph LR
+      A["$$\forall\complement\therefore\emptyset\exists\subset\because\empty\exist\supset\mapsto\varnothing\nexists\mid\to\implies\in\land\gets\impliedby\isin\lor\leftrightarrow\iff\notin\ni\notni\lnot$$"] --> B["$$\nabla\Im\Reals\jmath\partial\image\wp\aleph\Game\weierp\alef\Finv\N\Z\alefsym\cnums\natnums\beth\Complex\R\gimel\ell\Re\daleth\hbar\real\eth\hslash\reals$$"]
+    </pre>
+    <hr />
+
+    <h3>flowchart</h3>
+    <pre class="mermaid">
+      graph LR
+      A["$$\forall\complement\therefore\emptyset\exists\subset\because\empty\exist\supset\mapsto\varnothing\nexists\mid\to\implies\in\land\gets\impliedby\isin\lor\leftrightarrow\iff\notin\ni\notni\lnot$$"] --> B["$$\nabla\Im\Reals\jmath\partial\image\wp\aleph\Game\weierp\alef\Finv\N\Z\alefsym\cnums\natnums\beth\Complex\R\gimel\ell\Re\daleth\hbar\real\eth\hslash\reals$$"]
+    </pre>
+    <hr />
+
     <hr />
 
     <pre class="mermaid">
@@ -1524,11 +1575,11 @@ <h3>flowchart</h3>
       F{Flow 2} == Choice 2.1 ==> H[Feedback node]
       H[Feedback node] ==> B[Step 1]
       F{Flow 2} == Choice 2.2 ==> G((Finish))
-      
+
       linkStyle 0,1,4,6,7,8,9 stroke:gold, stroke-width:4px
 
       classDef active_node fill:#0CF,stroke:#09F,stroke-width:6px
-      classDef unactive_node fill:#e0e0e0,stroke:#bdbdbd,stroke-width:3px      
+      classDef unactive_node fill:#e0e0e0,stroke:#bdbdbd,stroke-width:3px
       classDef bugged_node fill:#F88,stroke:#F22,stroke-width:3px
       classDef start_node,finish_node fill:#3B1,stroke:#391,stroke-width:8px
 

demos/sequence.html

@@ -16,9 +16,9 @@
   <body>
     <h1>Sequence diagram demos</h1>
     <pre class="mermaid">
-		sequenceDiagram
-			accTitle: test the accTitle
-			accDescr: Test a description
+    sequenceDiagram
+      accTitle: test the accTitle
+      accDescr: Test a description
 
 			participant Alice
 			participant Bob
@@ -31,39 +31,39 @@ <h1>Sequence diagram demos</h1>
 			rect rgb(200, 220, 100)
 			rect rgb(200, 255, 200)
 
-			Alice ->> Bob: Hello Bob, how are you?
-			Bob-->>John: How about you John?
-			end
+      Alice ->> Bob: Hello Bob, how are you?
+      Bob-->>John: How about you John?
+      end
 
-			Bob--x Alice: I am good thanks!
-			Bob-x John: I am good thanks!
-			Note right of John: John thinks a long<br />long time, so long<br />that the text does<br />not fit on a row.
+      Bob--x Alice: I am good thanks!
+      Bob-x John: I am good thanks!
+      Note right of John: John thinks a long<br />long time, so long<br />that the text does<br />not fit on a row.
 
-			Bob-->Alice: Checking with John...
-			Note over John:wrap: John looks like he's still thinking, so Bob prods him a bit.
-			Bob-x John: Hey John - we're still waiting to know<br />how you're doing
-			Note over John:nowrap: John's trying hard not to break his train of thought.
-			Bob-x John:wrap: John! Are you still debating about how you're doing? How long does it take??
-			Note over John: After a few more moments, John<br />finally snaps out of it.
-			end
+      Bob-->Alice: Checking with John...
+      Note over John:wrap: John looks like he's still thinking, so Bob prods him a bit.
+      Bob-x John: Hey John - we're still waiting to know<br />how you're doing
+      Note over John:nowrap: John's trying hard not to break his train of thought.
+      Bob-x John:wrap: John! Are you still debating about how you're doing? How long does it take??
+      Note over John: After a few more moments, John<br />finally snaps out of it.
+      end
 
-			autonumber off
-			alt either this
-			Alice->>+John: Yes
-			John-->>-Alice: OK
-			else or this
-			autonumber
-			Alice->>John: No
-			else or this will happen
-			Alice->John: Maybe
-			end
-			autonumber 200
-			par this happens in parallel
-			Alice -->> Bob: Parallel message 1
-			and
-			Alice -->> John: Parallel message 2
-			end
-	</pre>
+      autonumber off
+      alt either this
+      Alice->>+John: Yes
+      John-->>-Alice: OK
+      else or this
+      autonumber
+      Alice->>John: No
+      else or this will happen
+      Alice->John: Maybe
+      end
+      autonumber 200
+      par this happens in parallel
+      Alice -->> Bob: Parallel message 1
+      and
+      Alice -->> John: Parallel message 2
+      end
+  </pre>
     <hr />
     <pre class="mermaid">
     ---
@@ -153,18 +153,18 @@ <h1>Sequence diagram demos</h1>
     <hr />
 
     <pre class="mermaid">
-      sequenceDiagram
-      box lightgreen Alice & John
-      participant A
-      participant J
-      end
-      box Another Group very very long description not wrapped
-      participant B
-      end
-      A->>J: Hello John, how are you?
-      J->>A: Great!
-      A->>B: Hello Bob, how are you ?
-      </pre
+        sequenceDiagram
+        box lightgreen Alice & John
+        participant A
+        participant J
+        end
+        box Another Group very very long description not wrapped
+        participant B
+        end
+        A->>J: Hello John, how are you?
+        J->>A: Great!
+        A->>B: Hello Bob, how are you ?
+        </pre
     >
     <hr />
 
@@ -188,6 +188,49 @@ <h1>Sequence diagram demos</h1>
       end
     </pre>
 
+    <hr />
+
+    <pre class="mermaid">
+    sequenceDiagram
+    participant 1 as $$\frac{\lim_{x\rightarrow0}{\frac{1}{x}}}{\frac{-b\pm\sqrt{b^2-4ac}}{2a}}$$
+    participant 2 as $$\beta$$
+    participant 3 as $$\delta$$
+    participant 4 as $$\frac{\frac{\lim_{x\rightarrow0}{\frac{1}{x}}}{\frac{-b\pm\sqrt{b^2-4ac}}{2a}}}{\frac{\text{d}}{\text{d}x}{x^2}}$$
+    1->>2: $$\sqrt{2}$$
+    note right of 2: $$\frac{1+\frac{1+\frac{1+\frac{1}{2}}{2}}{2}}{2}+\frac{-b\pm\sqrt{b^2-4ac}}{2a}$$
+    2->>3: $$\frac{\lim_{x\rightarrow0}{\frac{1}{x}}}{\frac{-b\pm\sqrt{b^2-4ac}}{2a}}$$
+    note right of 3: $$\frac{-b\pm\sqrt{b^2-4ac}}{2a}$$
+    3->>4: $$\lim_{x\rightarrow0}{\frac{1}{x}}$$;
+    note right of 4: multiline
+    4->>1: multiline<br />using #lt;br /#gt;
+    note right of 1: multiline<br />$$\frac{1}{2}$$<br />3rd line
+    </pre>
+    <hr />
+    <pre class="mermaid">
+      sequenceDiagram
+      autonumber
+      participant 1 as $$\alpha$$lex
+      participant 2 as $$\beta$$ob
+      participant 3 as $$\theta$$iffany
+      1->>2: Hello John, does&nbsp; $$\frac{1}{2}+1=2$$?
+      loop $$\frac{1}{2}+1=2$$
+          2->>2: $$\frac{1}{2}+1=\frac{3}{2}$$
+      end
+      Note right of 2: $$x = \begin{cases} 1 &\text{if } \frac{1}{2}+1=2 \\ 0 &\text{if } \frac{1}{2}+1\ne2 \end{cases}$$
+      2-->>1: $$\frac{1}{2}+1\ne2\implies 1$$
+      2->>3: $$\frac{\text{d}}{\text{d}x}{3x^2+2x+1}$$
+      3-->>2: $$6x+2$$
+    </pre>
+
+    <hr />
+
+    <pre class="mermaid">
+    sequenceDiagram
+      actor Alice
+      actor John
+      Alice-xJohn: Hello John, how are you?
+      John--xAlice: Great!
+    </pre>
     <script type="module">
       import mermaid from './mermaid.esm.mjs';
       mermaid.initialize({

docs/config/math.md

@@ -0,0 +1,86 @@
+> **Warning**
+>
+> ## THIS IS AN AUTOGENERATED FILE. DO NOT EDIT.
+>
+> ## Please edit the corresponding file in [/packages/mermaid/src/docs/config/math.md](../../packages/mermaid/src/docs/config/math.md).
+
+# Math Configuration (v\<MERMAID_RELEASE_VERSION>+)
+
+Mermaid supports rendering mathematical expressions through the [KaTeX](https://katex.org/) typesetter.
+
+## Usage
+
+To render math within a diagram, surround the mathematical expression with the `$$` delimiter.
+
+Note that at the moment, the only supported diagrams are below:
+
+### Flowcharts
+
+```mermaid-example
+ graph LR
+      A["$$x^2$$"] -->|"$$\sqrt{x+3}$$"| B("$$\frac{1}{2}$$")
+      A -->|"$$\overbrace{a+b+c}^{\text{note}}$$"| C("$$\pi r^2$$")
+      B --> D("$$x = \begin{cases} a &\text{if } b \\ c &\text{if } d \end{cases}$$")
+      C --> E("$$x(t)=c_1\begin{bmatrix}-\cos{t}+\sin{t}\\ 2\cos{t} \end{bmatrix}e^{2t}$$")
+```
+
+```mermaid
+ graph LR
+      A["$$x^2$$"] -->|"$$\sqrt{x+3}$$"| B("$$\frac{1}{2}$$")
+      A -->|"$$\overbrace{a+b+c}^{\text{note}}$$"| C("$$\pi r^2$$")
+      B --> D("$$x = \begin{cases} a &\text{if } b \\ c &\text{if } d \end{cases}$$")
+      C --> E("$$x(t)=c_1\begin{bmatrix}-\cos{t}+\sin{t}\\ 2\cos{t} \end{bmatrix}e^{2t}$$")
+```
+
+### Sequence
+
+```mermaid-example
+sequenceDiagram
+    autonumber
+    participant 1 as $$\alpha$$
+    participant 2 as $$\beta$$
+    1->>2: Solve: $$\sqrt{2+2}$$
+    2-->>1: Answer: $$2$$
+    Note right of 2: $$\sqrt{2+2}=\sqrt{4}=2$$
+```
+
+```mermaid
+sequenceDiagram
+    autonumber
+    participant 1 as $$\alpha$$
+    participant 2 as $$\beta$$
+    1->>2: Solve: $$\sqrt{2+2}$$
+    2-->>1: Answer: $$2$$
+    Note right of 2: $$\sqrt{2+2}=\sqrt{4}=2$$
+```
+
+## Legacy Support
+
+By default, MathML is used for rendering mathematical expressions. If you have users on [unsupported browsers](https://caniuse.com/?search=mathml), `legacyMathML` can be set in the config to fall back to CSS rendering. Note that **you must provide KaTeX's stylesheets on your own** as they do not come bundled with Mermaid.
+
+Example with legacy mode enabled (the latest version of KaTeX's stylesheet can be found on their [docs](https://katex.org/docs/browser.html)):
+
+```html
+<!DOCTYPE html>
+<!-- KaTeX requires the use of the HTML5 doctype. Without it, KaTeX may not render properly -->
+<html lang="en">
+  <head>
+    <!-- Please ensure the stylesheet's version matches with the KaTeX version in your package-lock -->
+    <link
+      rel="stylesheet"
+      href="https://cdn.jsdelivr.net/npm/katex@{version_number}/dist/katex.min.css"
+      integrity="sha384-{hash}"
+      crossorigin="anonymous"
+    />
+  </head>
+
+  <body>
+    <script type="module">
+      import mermaid from './mermaid.esm.mjs';
+      mermaid.initialize({
+        legacyMathML: true,
+      });
+    </script>
+  </body>
+</html>
+```

packages/mermaid/package.json

@@ -70,6 +70,7 @@
     "dayjs": "^1.11.7",
     "dompurify": "^3.0.5",
     "elkjs": "^0.9.0",
+    "katex": "^0.16.9",
     "khroma": "^2.0.0",
     "lodash-es": "^4.17.21",
     "mdast-util-from-markdown": "^1.3.0",
@@ -89,6 +90,7 @@
     "@types/d3-shape": "^3.1.1",
     "@types/dompurify": "^3.0.2",
     "@types/jsdom": "^21.1.1",
+    "@types/katex": "^0.16.7",
     "@types/lodash-es": "^4.17.7",
     "@types/micromatch": "^4.0.2",
     "@types/prettier": "^2.7.2",