Allow overlapping notes

cSpell.json

@@ -59,6 +59,7 @@
     "knsv",
     "knut",
     "laganeckas",
+    "linetype",
     "lintstagedrc",
     "logmsg",
     "lucida",

cypress/integration/rendering/sequencediagram.spec.js

@@ -123,6 +123,29 @@ context('Sequence diagram', () => {
       }
     );
   });
+  it('should render a sequence diagram with par_over', () => {
+    imgSnapshotTest(
+      `
+        sequenceDiagram
+        participant Alice
+        participant Bob
+        participant John
+        par_over Section title
+          Alice ->> Bob: Message 1<br>Second line
+          Bob ->> John: Message 2
+        end
+        par_over Two line<br>section title
+          Note over Alice: Alice note
+          Note over Bob: Bob note<br>Second line
+          Note over John: John note
+        end
+        par_over Mixed section
+          Alice ->> Bob: Message 1
+          Note left of Bob: Alice/Bob Note
+        end
+      `
+    );
+  });
   context('font settings', () => {
     it('should render different note fonts when configured', () => {
       imgSnapshotTest(

demos/sequence.html

@@ -144,6 +144,26 @@ <h1>Sequence diagram demos</h1>
     >
     <hr />
 
+    <pre class="mermaid">
+      sequenceDiagram
+      participant Alice
+      participant Bob
+      participant John
+      par_over Section title
+        Alice ->> Bob: Message 1<br>Second line
+        Bob ->> John: Message 2
+      end
+      par_over Two line<br>section title
+        Note over Alice: Alice note
+        Note over Bob: Bob note<br>Second line
+        Note over John: John note
+      end
+      par_over Mixed section
+        Alice ->> Bob: Message 1
+        Note left of Bob: Alice/Bob Note
+      end
+    </pre>
+
     <script type="module">
       import mermaid from './mermaid.esm.mjs';
       mermaid.initialize({

packages/mermaid/src/diagrams/class/classDiagramGrammar.spec.ts

@@ -9,7 +9,7 @@ const getAbsolutePath = (relativePath: string) => {
 
 describe('class diagram grammar', function () {
   it('should have no conflicts', async function () {
-    const grammarSource = await readFile(getAbsolutePath('parser/classDiagram.jison'), 'utf8');
+    const grammarSource = await readFile(getAbsolutePath('./parser/classDiagram.jison'), 'utf8');
     const grammarParser = new LALRGenerator(grammarSource, {});
     expect(grammarParser.conflicts).toBe(0);
   });

packages/mermaid/src/diagrams/common/common.ts

@@ -138,6 +138,32 @@ const getUrl = (useAbsolute: boolean): string => {
 export const evaluate = (val?: string | boolean): boolean =>
   val === false || ['false', 'null', '0'].includes(String(val).trim().toLowerCase()) ? false : true;
 
+/**
+ * Wrapper around Math.max which removes non-numeric values
+ * Returns the larger of a set of supplied numeric expressions.
+ * @param values - Numeric expressions to be evaluated
+ * @returns The smaller value
+ */
+export const getMax = function (...values: number[]): number {
+  const newValues: number[] = values.filter((value) => {
+    return !isNaN(value);
+  });
+  return Math.max(...newValues);
+};
+
+/**
+ * Wrapper around Math.min which removes non-numeric values
+ * Returns the smaller of a set of supplied numeric expressions.
+ * @param values - Numeric expressions to be evaluated
+ * @returns The smaller value
+ */
+export const getMin = function (...values: number[]): number {
+  const newValues: number[] = values.filter((value) => {
+    return !isNaN(value);
+  });
+  return Math.min(...newValues);
+};
+
 /**
  * Makes generics in typescript syntax
  *
@@ -180,4 +206,6 @@ export default {
   removeScript,
   getUrl,
   evaluate,
+  getMax,
+  getMin,
 };

packages/mermaid/src/diagrams/sequence/parser/sequenceDiagram.jison

@@ -47,6 +47,7 @@
 "alt"                                                           { this.begin('LINE'); return 'alt'; }
 "else"                                                          { this.begin('LINE'); return 'else'; }
 "par"                                                           { this.begin('LINE'); return 'par'; }
+"par_over" 														{ this.begin('LINE'); return 'par_over'; }
 "and"                                                           { this.begin('LINE'); return 'and'; }
 "critical"                                                      { this.begin('LINE'); return 'critical'; }
 "option"                                                        { this.begin('LINE'); return 'option'; }
@@ -190,6 +191,14 @@ statement
 		// End
 		$3.push({type: 'parEnd', signalType: yy.LINETYPE.PAR_END});
 		$$=$3;}
+	| par_over restOfLine par_sections end
+	{
+		// Parallel (overlapped) start
+		$3.unshift({type: 'parStart', parText:yy.parseMessage($2), signalType: yy.LINETYPE.PAR_OVER_START});
+		// Content in par is already in $3
+		// End
+		$3.push({type: 'parEnd', signalType: yy.LINETYPE.PAR_END});
+		$$=$3;}
 	| critical restOfLine option_sections end
 	{
 		// critical start

packages/mermaid/src/diagrams/sequence/sequenceDb.js

@@ -286,6 +286,7 @@ export const LINETYPE = {
   CRITICAL_END: 29,
   BREAK_START: 30,
   BREAK_END: 31,
+  PAR_OVER_START: 32,
 };
 
 export const ARROWTYPE = {

packages/mermaid/src/diagrams/sequence/sequenceDiagram.spec.js

@@ -1126,6 +1126,29 @@ end`;
     expect(messages[1].from).toBe('Alice');
     expect(messages[2].from).toBe('Bob');
   });
+  it('it should handle par_over statements', async () => {
+    const str = `
+sequenceDiagram
+par_over Parallel overlap
+Alice ->> Bob: Message
+Note left of Alice: Alice note
+Note right of Bob: Bob note
+end`;
+
+    await mermaidAPI.parse(str);
+    const actors = diagram.db.getActors();
+
+    expect(actors.Alice.description).toBe('Alice');
+    expect(actors.Bob.description).toBe('Bob');
+
+    const messages = diagram.db.getMessages();
+
+    expect(messages.length).toBe(5);
+    expect(messages[0].message).toBe('Parallel overlap');
+    expect(messages[1].from).toBe('Alice');
+    expect(messages[2].from).toBe('Alice');
+    expect(messages[3].from).toBe('Bob');
+  });
   it('should handle special characters in signals', async () => {
     const str = 'sequenceDiagram\n' + 'Alice->Bob: -:<>,;# comment';