feat(er): add entity name alias

cypress/integration/rendering/erDiagram.spec.js

@@ -305,4 +305,21 @@ ORDER ||--|{ LINE-ITEM : contains
       {}
     );
   });
+
+  it('should render entities with entity name aliases', () => {
+    imgSnapshotTest(
+      `
+    erDiagram
+      p[Person] {
+        varchar(64) firstName
+        varchar(64) lastName
+      }
+      c["Customer Account"] {
+        varchar(128) email
+      }
+      p ||--o| c : has
+      `,
+      { logLevel: 1 }
+    );
+  });
 });

demos/er.html

@@ -110,6 +110,20 @@
         }
         MANUFACTURER only one to zero or more CAR : makes
     </pre>
+    <hr />
+
+    <pre class="mermaid">
+    erDiagram
+      p[Person] {
+          string firstName
+          string lastName
+      }
+      a["Customer Account"] {
+          string email
+      }
+      p ||--o| a : has
+    </pre>
+    <hr />
 
     <script type="module">
       import mermaid from './mermaid.esm.mjs';

docs/syntax/entityRelationshipDiagram.md

@@ -198,6 +198,34 @@ erDiagram
 
 The `type` values must begin with an alphabetic character and may contain digits, hyphens, underscores, parentheses and square brackets. The `name` values follow a similar format to `type`, but may start with an asterisk as another option to indicate an attribute is a primary key. Other than that, there are no restrictions, and there is no implicit set of valid data types.
 
+### Entity Name Aliases (v\<MERMAID_RELEASE_VERSION>+)
+
+An alias can be added to an entity using square brackets. If provided, the alias will be showed in the diagram instead of the entity name.
+
+```mermaid-example
+erDiagram
+    p[Person] {
+        string firstName
+        string lastName
+    }
+    a["Customer Account"] {
+        string email
+    }
+    p ||--o| a : has
+```
+
+```mermaid
+erDiagram
+    p[Person] {
+        string firstName
+        string lastName
+    }
+    a["Customer Account"] {
+        string email
+    }
+    p ||--o| a : has
+```
+
 #### Attribute Keys and Comments
 
 Attributes may also have a `key` or comment defined. Keys can be `PK`, `FK` or `UK`, for Primary Key, Foreign Key or Unique Key. To specify multiple key constraints on a single attribute, separate them with a comma (e.g., `PK, FK`).. A `comment` is defined by double quotes at the end of an attribute. Comments themselves cannot have double-quote characters in them.

packages/mermaid/src/diagrams/er/erDb.js

@@ -32,10 +32,13 @@ export const parseDirective = function (statement, context, type) {
   mermaidAPI.parseDirective(this, statement, context, type);
 };
 
-const addEntity = function (name) {
+const addEntity = function (name, alias = undefined) {
   if (entities[name] === undefined) {
-    entities[name] = { attributes: [] };
+    entities[name] = { attributes: [], alias: alias };
     log.info('Added new entity :', name);
+  } else if (entities[name] && !entities[name].alias && alias) {
+    entities[name].alias = alias;
+    log.info(`Add alias '${alias}' to entity '${name}'`);
   }
 
   return entities[name];

packages/mermaid/src/diagrams/er/erRenderer.js

@@ -326,7 +326,7 @@ const drawEntities = function (svgNode, entities, graph) {
       .style('text-anchor', 'middle')
       .style('font-family', getConfig().fontFamily)
       .style('font-size', conf.fontSize + 'px')
-      .text(entityName);
+      .text(entities[entityName].alias ?? entityName);
 
     const { width: entityWidth, height: entityHeight } = drawAttributes(
       groupNode,

packages/mermaid/src/diagrams/er/parser/erDiagram.jison

@@ -35,6 +35,8 @@ accDescr\s*"{"\s*                                { this.begin("acc_descr_multili
 <block>[\n]+                    /* nothing */
 <block>"}"                      { this.popState(); return 'BLOCK_STOP'; }
 <block>.                        return yytext[0];
+"["                             return 'SQS';
+"]"                             return 'SQE';
 
 "one or zero"                   return 'ZERO_OR_ONE';
 "one or more"                   return 'ONE_OR_MORE';
@@ -102,17 +104,21 @@ statement
           yy.addEntity($1);
           yy.addEntity($3);
           yy.addRelationship($1, $5, $3, $2);
-          /*console.log($1 + $2 + $3 + ':' + $5);*/
       }
     | entityName BLOCK_START attributes BLOCK_STOP
       {
-          /* console.log('detected block'); */
           yy.addEntity($1);
           yy.addAttributes($1, $3);
-          /* console.log('handled block'); */
       }
     | entityName BLOCK_START BLOCK_STOP { yy.addEntity($1); }
     | entityName { yy.addEntity($1); }
+    | entityName SQS entityName SQE BLOCK_START attributes BLOCK_STOP
+      {
+          yy.addEntity($1, $3);
+          yy.addAttributes($1, $6);
+      }
+    | entityName SQS entityName SQE BLOCK_START BLOCK_STOP { yy.addEntity($1, $3); }
+    | entityName SQS entityName SQE { yy.addEntity($1, $3); }
     | title title_value  { $$=$2.trim();yy.setAccTitle($$); }
     | acc_title acc_title_value  { $$=$2.trim();yy.setAccTitle($$); }
     | acc_descr acc_descr_value  { $$=$2.trim();yy.setAccDescription($$); }

packages/mermaid/src/diagrams/er/parser/erDiagram.spec.js

@@ -133,6 +133,43 @@ describe('when parsing ER diagram it...', function () {
       const entities = erDb.getEntities();
       expect(entities.hasOwnProperty(hyphensUnderscore)).toBe(true);
     });
+
+    it('can have an alias', function () {
+      const entity = 'foo';
+      const alias = 'bar';
+      erDiagram.parser.parse(`erDiagram\n${entity}["${alias}"]\n`);
+      const entities = erDb.getEntities();
+      expect(entities.hasOwnProperty(entity)).toBe(true);
+      expect(entities[entity].alias).toBe(alias);
+    });
+
+    it('can have an alias even if the relationship is defined before class', function () {
+      const firstEntity = 'foo';
+      const secondEntity = 'bar';
+      const alias = 'batman';
+      erDiagram.parser.parse(
+        `erDiagram\n${firstEntity} ||--o| ${secondEntity} : rel\nclass ${firstEntity}["${alias}"]\n`
+      );
+      const entities = erDb.getEntities();
+      expect(entities.hasOwnProperty(firstEntity)).toBe(true);
+      expect(entities.hasOwnProperty(secondEntity)).toBe(true);
+      expect(entities[firstEntity].alias).toBe(alias);
+      expect(entities[secondEntity].alias).toBeUndefined();
+    });
+
+    it('can have an alias even if the relationship is defined after class', function () {
+      const firstEntity = 'foo';
+      const secondEntity = 'bar';
+      const alias = 'batman';
+      erDiagram.parser.parse(
+        `erDiagram\nclass ${firstEntity}["${alias}"]\n${firstEntity} ||--o| ${secondEntity} : rel\n`
+      );
+      const entities = erDb.getEntities();
+      expect(entities.hasOwnProperty(firstEntity)).toBe(true);
+      expect(entities.hasOwnProperty(secondEntity)).toBe(true);
+      expect(entities[firstEntity].alias).toBe(alias);
+      expect(entities[secondEntity].alias).toBeUndefined();
+    });
   });
 
   describe('attribute name', () => {

packages/mermaid/src/docs/syntax/entityRelationshipDiagram.md

@@ -144,6 +144,22 @@ erDiagram
 
 The `type` values must begin with an alphabetic character and may contain digits, hyphens, underscores, parentheses and square brackets. The `name` values follow a similar format to `type`, but may start with an asterisk as another option to indicate an attribute is a primary key. Other than that, there are no restrictions, and there is no implicit set of valid data types.
 
+### Entity Name Aliases (v<MERMAID_RELEASE_VERSION>+)
+
+An alias can be added to an entity using square brackets. If provided, the alias will be showed in the diagram instead of the entity name.
+
+```mermaid-example
+erDiagram
+    p[Person] {
+        string firstName
+        string lastName
+    }
+    a["Customer Account"] {
+        string email
+    }
+    p ||--o| a : has
+```
+
 #### Attribute Keys and Comments
 
 Attributes may also have a `key` or comment defined. Keys can be `PK`, `FK` or `UK`, for Primary Key, Foreign Key or Unique Key. To specify multiple key constraints on a single attribute, separate them with a comma (e.g., `PK, FK`).. A `comment` is defined by double quotes at the end of an attribute. Comments themselves cannot have double-quote characters in them.