ci: increase number of shards when running Next.js repo e2e tests (#2748)

* ci: increase number of shards when running Next.js repo e2e tests

* test: set NEXT_PRIVATE_TEST_MODE when running Next.js repo tests

* test: re-enable running tests against canary for upcoming changes visibility

Author: pieh

Diff for: .github/workflows/test-e2e.yml

@@ -56,16 +56,16 @@ jobs:
         run: |
           if [ "${{ github.event_name }}" == "workflow_dispatch" ]; then
             VERSION_SELECTORS=[${{ github.event.inputs.versions }}]
-            echo "group=[1, 2, 3, 4]" >> $GITHUB_OUTPUT
-            echo "total=4" >> $GITHUB_OUTPUT
+            echo "group=[1, 2, 3, 4, 5, 6]" >> $GITHUB_OUTPUT
+            echo "total=6" >> $GITHUB_OUTPUT
           elif [ "${{ github.event_name }}" == "pull_request" ]; then
             VERSION_SELECTORS=[\"latest\"]
-            echo "group=[1, 2, 3, 4]" >> $GITHUB_OUTPUT
-            echo "total=4" >> $GITHUB_OUTPUT
+            echo "group=[1, 2, 3, 4, 5, 6]" >> $GITHUB_OUTPUT
+            echo "total=6" >> $GITHUB_OUTPUT
           else
-            VERSION_SELECTORS=[\"latest\",\"canary\",\"14.2.15\",\"13.5.1\"]
-            echo "group=[1, 2, 3, 4]" >> $GITHUB_OUTPUT
-            echo "total=4" >> $GITHUB_OUTPUT
+            VERSION_SELECTORS=[\"latest\",\"canary\"]
+            echo "group=[1, 2, 3, 4, 5, 6]" >> $GITHUB_OUTPUT
+            echo "total=6" >> $GITHUB_OUTPUT
           fi
 
           VERSION_SPEC="["

Diff for: tests/netlify-deploy.ts

@@ -90,6 +90,10 @@ export class NextDeployInstance extends NextInstance {
           command = "npm run build"
           publish = ".next"
 
+          [build.environment]
+          # this allows to use "CanaryOnly" features with next@latest
+          NEXT_PRIVATE_TEST_MODE = "e2e"
+
           [[plugins]]
           package = "${runtimePackageName}"
           `