fix(editors/later-binding): Resolve absent prefix in ExtRef for later binding subscription (openscd#1026)

* Resolve absent prefix in ExtRef for later binding subscription, part of openscd#1005

* Correct approach from review feedback

* Add tests

* Update snapshots

* Tidy up, update snapshots, update tests

Author: danyill

src/editors/subscription/later-binding/ext-ref-later-binding-list.ts

@@ -94,8 +94,8 @@ export class ExtRefLaterBindingList extends LitElement {
     attributeName: string
   ): boolean {
     return (
-      extRefElement.getAttribute(attributeName) ===
-      this.currentSelectedFcdaElement?.getAttribute(attributeName)
+      (extRefElement.getAttribute(attributeName) ?? '') ===
+        (this.currentSelectedFcdaElement?.getAttribute(attributeName) ?? '')
     );
   }
 

test/integration/editors/GooseSubscriberLaterBinding.test.ts

@@ -45,7 +45,7 @@ describe('GOOSE Subscribe Later Binding Plugin', () => {
     ).to.be.equal(0);
     expect(
       extRefListElement['getAvailableExtRefElements']().length
-    ).to.be.equal(2);
+    ).to.be.equal(4);
 
     (<HTMLElement>(
       extRefListElement.shadowRoot!.querySelector(
@@ -59,7 +59,7 @@ describe('GOOSE Subscribe Later Binding Plugin', () => {
     ).to.be.equal(1);
     expect(
       extRefListElement['getAvailableExtRefElements']().length
-    ).to.be.equal(1);
+    ).to.be.equal(3);
   });
 
   it('when unsubscribing a subscribed ExtRef then the lists are changed', async () => {
@@ -79,7 +79,7 @@ describe('GOOSE Subscribe Later Binding Plugin', () => {
     ).to.be.equal(2);
     expect(
       extRefListElement['getAvailableExtRefElements']().length
-    ).to.be.equal(2);
+    ).to.be.equal(4);
     (<HTMLElement>(
       extRefListElement.shadowRoot!.querySelector(
         'mwc-list-item[value="GOOSE_Subscriber>>Earth_Switch> CSWI 1>GOOSE:GOOSE2 QB2_Disconnector/ LLN0  GOOSE_Publisher QB2_Disconnector/ CSWI 1 Pos q@Pos;CSWI1/Pos/q"]'
@@ -92,6 +92,6 @@ describe('GOOSE Subscribe Later Binding Plugin', () => {
     ).to.be.equal(1);
     expect(
       extRefListElement['getAvailableExtRefElements']().length
-    ).to.be.equal(3);
+    ).to.be.equal(5);
   });
 });