Reset embed mocks on every request, stop request to instagram (#15046)

* Make sure mocks are set up for every embedding test

* Stop request to instagram

packages/e2e-tests/specs/embedding.test.js

@@ -5,6 +5,7 @@ import {
 	clickBlockAppender,
 	createNewPost,
 	createEmbeddingMatcher,
+	createURLMatcher,
 	setUpResponseMocking,
 	createJSONResponse,
 	getEditedPostContent,
@@ -124,6 +125,12 @@ const MOCK_RESPONSES = [
 		match: createEmbeddingMatcher( 'https://twitter.com/wooyaygutenberg123454312' ),
 		onRequestMatch: createJSONResponse( MOCK_CANT_EMBED_RESPONSE ),
 	},
+	// Respond to the instagram URL with a non-image response, doesn't matter what it is,
+	// just make sure the image errors.
+	{
+		match: createURLMatcher( 'https://www.instagram.com/p/Bvl97o2AK6x/' ),
+		onRequestMatch: createJSONResponse( MOCK_CANT_EMBED_RESPONSE ),
+	},
 ];
 
 const addAllEmbeds = async () => {
@@ -178,8 +185,10 @@ const addAllEmbeds = async () => {
 };
 
 describe( 'Embedding content', () => {
-	beforeAll( async () => await setUpResponseMocking( MOCK_RESPONSES ) );
-	beforeEach( createNewPost );
+	beforeEach( async () => {
+		await setUpResponseMocking( MOCK_RESPONSES );
+		await createNewPost();
+	} );
 
 	it( 'should render embeds in the correct state', async () => {
 		await addAllEmbeds();