feat: add tag support

source/prototype.ts

@@ -26,22 +26,27 @@ export class Xception extends Error {
   /** running context */
   public meta: Record<string, unknown>;
 
+  /** additional associations */
+  public tags: string[];
+
   /**
    * @param message error message
    * @param options additional options for the error
    * @param options.cause upstream error
    * @param options.namespace namespace of the error
    * @param options.meta context where the error occur
+   * @param options.tags additional associations for the error
    */
   constructor(
     message: string,
     options?: {
       cause?: unknown;
       namespace?: string;
       meta?: Record<string, unknown>;
+      tags?: string[];
     },
   ) {
-    const { cause, namespace, meta = {} } = { ...options };
+    const { cause, namespace, meta = {}, tags = [] } = { ...options };
 
     super(message);
     this.cause = cause;
@@ -66,5 +71,8 @@ export class Xception extends Error {
             cause.stack,
           ].join('\n')
         : this.stack;
+
+    // attach tags to the error
+    this.tags = cause instanceof Xception ? [...cause.tags, ...tags] : tags;
   }
 }

source/render.ts

@@ -59,6 +59,10 @@ function renderAssociations(error: unknown): string | null {
     blocks.push(chalk.blue.underline(error.namespace));
   }
 
+  if (error instanceof Xception && error.tags.length) {
+    blocks.push(...error.tags.map((tag) => chalk.cyan.bold(tag)));
+  }
+
   return blocks.length ? '\n    ' + blocks.join(' ') : null;
 }
 

spec/prototype.spec.ts

@@ -17,7 +17,7 @@ import { Xception } from '#prototype';
 
 class NewError extends Xception {
   constructor(options?: { cause?: unknown }) {
-    super('new error', { ...options });
+    super('new error', { ...options, tags: ['new'] });
   }
 }
 
@@ -29,6 +29,7 @@ function getExtendedError(): Xception {
       cause,
       namespace: 'test:xception',
       meta: { name: 'xception' },
+      tags: ['extended'],
     });
   }
 }
@@ -62,6 +63,10 @@ describe('cl:Xception', () => {
     expect(extendedError.meta).toEqual({ name: 'xception' });
   });
 
+  it('passes tags to the inherited class', () => {
+    expect(newError.tags).toEqual(['extended', 'new']);
+  });
+
   it('keeps its own stack if the attached error has no stack', () => {
     const error = new Xception('message', {
       cause: { name: 'GenericError', message: 'error' },
@@ -71,9 +76,10 @@ describe('cl:Xception', () => {
   });
 
   it('takes a normal error if no origin is attached', () => {
-    const error = new Xception('message');
+    const error = new Xception('message', { tags: ['tag'] });
 
     expect(error.stack).toContain('Xception');
+    expect(error.tags).toEqual(['tag']);
   });
 
   it('bears the right error type', () => {

spec/render.spec.ts

@@ -157,6 +157,7 @@ describe('fn:renderStack', () => {
     const rendered = renderStack(
       new Xception('message', {
         namespace: 'xception',
+        tags: ['tag1', 'tag2'],
         meta: { name: 'xception' },
       }),
     );
@@ -166,7 +167,7 @@ describe('fn:renderStack', () => {
     expect(plain).toContain(
       '[Xception] message\n' +
         '\n' +
-        '    xception\n' +
+        '    xception tag1 tag2\n' +
         '\n' +
         '    name: xception\n' +
         '\n' +