fix(#4256): Keep error diagram on screen

cypress/integration/rendering/erDiagram.spec.js

@@ -10,7 +10,6 @@ describe('Entity Relationship Diagram', () => {
       `,
       { logLevel: 1 }
     );
-    cy.get('svg');
   });
 
   it('should render an ER diagram with a recursive relationship', () => {
@@ -23,7 +22,6 @@ describe('Entity Relationship Diagram', () => {
       `,
       { logLevel: 1 }
     );
-    cy.get('svg');
   });
 
   it('should render an ER diagram with multiple relationships between the same two entities', () => {
@@ -35,7 +33,6 @@ describe('Entity Relationship Diagram', () => {
       `,
       { logLevel: 1 }
     );
-    cy.get('svg');
   });
 
   it('should render a cyclical ER diagram', () => {
@@ -48,7 +45,6 @@ describe('Entity Relationship Diagram', () => {
       `,
       { logLevel: 1 }
     );
-    cy.get('svg');
   });
 
   it('should render a not-so-simple ER diagram', () => {
@@ -66,7 +62,6 @@ describe('Entity Relationship Diagram', () => {
       `,
       { logLevel: 1 }
     );
-    cy.get('svg');
   });
 
   it('should render multiple ER diagrams', () => {
@@ -85,7 +80,6 @@ describe('Entity Relationship Diagram', () => {
       ],
       { logLevel: 1 }
     );
-    cy.get('svg');
   });
 
   it('should render an ER diagram with blank or empty labels', () => {
@@ -98,7 +92,6 @@ describe('Entity Relationship Diagram', () => {
       `,
       { logLevel: 1 }
     );
-    cy.get('svg');
   });
 
   it('should render an ER diagrams when useMaxWidth is true (default)', () => {
@@ -151,7 +144,6 @@ describe('Entity Relationship Diagram', () => {
       `,
       { er: { useMaxWidth: false } }
     );
-    cy.get('svg');
   });
 
   it('should render entities with and without attributes', () => {
@@ -164,7 +156,6 @@ describe('Entity Relationship Diagram', () => {
       `,
       { logLevel: 1 }
     );
-    cy.get('svg');
   });
 
   it('should render entities with generic and array attributes', () => {
@@ -179,7 +170,6 @@ describe('Entity Relationship Diagram', () => {
       `,
       { logLevel: 1 }
     );
-    cy.get('svg');
   });
 
   it('should render entities with length in attributes type', () => {
@@ -193,7 +183,6 @@ describe('Entity Relationship Diagram', () => {
       `,
       { logLevel: 1 }
     );
-    cy.get('svg');
   });
 
   it('should render entities and attributes with big and small entity names', () => {
@@ -209,7 +198,6 @@ describe('Entity Relationship Diagram', () => {
       `,
       { logLevel: 1 }
     );
-    cy.get('svg');
   });
 
   it('should render entities with keys', () => {
@@ -228,7 +216,6 @@ describe('Entity Relationship Diagram', () => {
       `,
       { logLevel: 1 }
     );
-    cy.get('svg');
   });
 
   it('should render entities with comments', () => {
@@ -247,7 +234,6 @@ describe('Entity Relationship Diagram', () => {
       `,
       { logLevel: 1 }
     );
-    cy.get('svg');
   });
 
   it('should render entities with keys and comments', () => {
@@ -267,7 +253,6 @@ describe('Entity Relationship Diagram', () => {
       `,
       { logLevel: 1 }
     );
-    cy.get('svg');
   });
 
   it('should render entities with aliases', () => {
@@ -285,7 +270,6 @@ describe('Entity Relationship Diagram', () => {
       `,
       { logLevel: 1 }
     );
-    cy.get('svg');
   });
 
   it('1433: should render a simple ER diagram with a title', () => {

cypress/integration/rendering/errorDiagram.spec.js

@@ -0,0 +1,36 @@
+import { imgSnapshotTest } from '../../helpers/util';
+
+describe('Error Diagrams', () => {
+  it('should render a simple ER diagram', () => {
+    imgSnapshotTest(
+      `
+      error
+      `,
+      { logLevel: 1 }
+    );
+  });
+
+  it('should render error diagram for actual errors', () => {
+    imgSnapshotTest(
+      `
+    flowchart TD
+      A[Christmas] --|Get money| B(Go shopping)
+      `,
+      { logLevel: 1 }
+    );
+  });
+
+  it('should render error for wrong ER diagram', () => {
+    imgSnapshotTest(
+      `
+    erDiagram
+        ATLAS-ORGANIZATION ||--|{ ATLAS-PROJECTS : "has many"
+        ATLAS-PROJECTS ||--|{ MONGODB-CLUSTERS : "has many"
+        ATLAS-PROJECTS ||--|{ ATLAS-TEAMS : "has many"
+        MONGODB-CLUSTERS ||..|{
+        ATLAS-TEAMS ||..|{
+      `,
+      { logLevel: 1 }
+    );
+  });
+});

demos/error.html

@@ -0,0 +1,38 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8" />
+    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
+    <title>Error | Mermaid Quick Test Page</title>
+    <link rel="icon" type="image/png" href="data:image/png;base64,iVBORw0KGgo=" />
+  </head>
+
+  <body>
+    <pre class="mermaid">
+      erDiagram
+        ATLAS-ORGANIZATION ||--|{ ATLAS-PROJECTS : "has many"
+        ATLAS-PROJECTS ||--|{ MONGODB-CLUSTERS : "has many"
+        ATLAS-PROJECTS ||--|{ ATLAS-TEAMS : "has many"
+    </pre>
+    <pre class="mermaid">
+      erDiagram
+        ATLAS-ORGANIZATION ||--|{ ATLAS-PROJECTS : "has many"
+        ATLAS-PROJECTS ||--|{ MONGODB-CLUSTERS : "has many"
+        ATLAS-PROJECTS ||--|{ ATLAS-TEAMS : "has many"
+        MONGODB-CLUSTERS ||..|{
+        ATLAS-TEAMS ||..|{
+    </pre>
+    <hr />
+    <pre class="mermaid">
+    flowchart TD
+      A[Christmas] -->|Get money| B(Go shopping)
+    </pre>
+    <pre class="mermaid">
+    flowchart TD
+      A[Christmas] --|Get money| B(Go shopping)
+    </pre>
+    <script type="module">
+      import mermaid from './mermaid.esm.mjs';
+    </script>
+  </body>
+</html>

packages/mermaid/src/diagram-api/diagram-orchestration.ts

@@ -13,7 +13,7 @@ import classDiagramV2 from '../diagrams/class/classDetector-V2';
 import state from '../diagrams/state/stateDetector';
 import stateV2 from '../diagrams/state/stateDetector-V2';
 import journey from '../diagrams/user-journey/journeyDetector';
-import error from '../diagrams/error/errorDetector';
+import errorDiagram from '../diagrams/error/errorDiagram';
 import flowchartElk from '../diagrams/flowchart/elk/detector';
 import timeline from '../diagrams/timeline/detector';
 import mindmap from '../diagrams/mindmap/detector';
@@ -28,6 +28,9 @@ export const addDiagrams = () => {
   // This is added here to avoid race-conditions.
   // We could optimize the loading logic somehow.
   hasLoadedDiagrams = true;
+  registerDiagram('error', errorDiagram, (text) => {
+    return text.toLowerCase().trim() === 'error';
+  });
   registerDiagram(
     '---',
     // --- diagram type may appear if YAML front-matter is not parsed correctly
@@ -57,7 +60,6 @@ export const addDiagrams = () => {
   );
   // Ordering of detectors is important. The first one to return true will be used.
   registerLazyLoadedDiagrams(
-    error,
     c4,
     classDiagramV2,
     classDiagram,

packages/mermaid/src/diagrams/error/errorDetector.ts

@@ -1,20 +0,0 @@
-import type { DiagramDetector, ExternalDiagramDefinition } from '../../diagram-api/types';
-
-const id = 'error';
-
-const detector: DiagramDetector = (text) => {
-  return text.toLowerCase().trim() === 'error';
-};
-
-const loader = async () => {
-  const { diagram } = await import('./errorDiagram');
-  return { id, diagram };
-};
-
-const plugin: ExternalDiagramDefinition = {
-  id,
-  detector,
-  loader,
-};
-
-export default plugin;

packages/mermaid/src/diagrams/error/errorDiagram.ts

@@ -19,3 +19,5 @@ export const diagram: DiagramDefinition = {
     // no op
   },
 };
+
+export default diagram;

packages/mermaid/src/diagrams/error/errorRenderer.ts

@@ -4,15 +4,13 @@ import { select } from 'd3';
 import { log } from '../../logger';
 import { getErrorMessage } from '../../utils';
 
-let conf = {};
-
 /**
  * Merges the value of `conf` with the passed `cnf`
  *
  * @param cnf - Config to merge
  */
-export const setConf = function (cnf: any) {
+export const setConf = function () {
-  conf = { ...conf, ...cnf };
+  // no-op
 };
 
 /**
@@ -78,7 +76,7 @@ export const draw = (_text: string, id: string, mermaidVersion: string) => {
       .attr('y', 250)
       .attr('font-size', '150px')
       .style('text-anchor', 'middle')
-      .text('Syntax error in graph');
+      .text('Syntax error in text');
     g.append('text') // text label for the x axis
       .attr('class', 'error-text')
       .attr('x', 1250)

packages/mermaid/src/mermaidAPI.ts

@@ -534,6 +534,10 @@ const render = async function (
 
   attachFunctions();
 
+  if (parseEncounteredException) {
+    throw parseEncounteredException;
+  }
+
   // -------------------------------------------------------------------------------
   // Remove the temporary HTML element if appropriate
   const tmpElementSelector = isSandboxed ? iFrameID_selector : enclosingDivID_selector;
@@ -542,10 +546,6 @@ const render = async function (
     node.remove();
   }
 
-  if (parseEncounteredException) {
-    throw parseEncounteredException;
-  }
-
   return {
     svg: svgCode,
     bindFunctions: diag.db.bindFunctions,