add fake fuzz test that will quickly fail

.github/workflows/fuzz-run-go.yml

@@ -112,3 +112,40 @@ jobs:
 
           When opening a PR with the fix, please include the test case file in your PR to prevent regressions.
           EOF
+
+      - name: Create new issue
+        if: ${{ failure() && steps.new-failure.outputs.file != '' }}
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const failureName = "${{ steps.new-failure.outputs.name }}";
+            const issueTitle = `${{ inputs.package-path }}: ${{ inputs.test-name }} failed (${failureName})`;
+
+            // Look for existing issue first with the same title.
+            const issues = await github.rest.search.issuesAndPullRequests({
+              q: `is:issue is:open repo:${{ github.repository }} in:title "${failureName}"`
+            })
+            const issue = issues.data.items.find((issue) => issue.title === issue.title);
+            if (issue) {
+              return;
+            }
+
+            // Create a new issue.
+            await github.rest.issues.create({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              title: issueTitle,
+              body: `
+            A new fuzz test failure was found in <code>${{ input.package-path }}</code>.
+
+            To reproduce the failure locally, run the following command using the GitHub CLI to download the corpus entry:
+
+            <pre lang="bash">gh run download --repo ${{ github.repository }} ${{ github.run_id }} -n failure-${{ steps.new-failure.outputs.package }}-${{ steps.new-failure.outputs.function }} --dir ${{ inputs.package-path }}/testdata/fuzz/${{ inputs.test-name }}</pre>
+
+            When opening a PR with the fix, please include in the corpus entry in your commit to prevent regressions.
+
+            [Link to failed run](${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }})
+            `,
+
+              labels: ['bug'],
+            })

internal/fuzztests/fake_fuzz_test.go

@@ -0,0 +1,27 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func FuzzFails(f *testing.F) {
+	f.Add(0, 0)
+	f.Add(2, 4)
+
+	f.Fuzz(func(t *testing.T, a, b int) {
+		expect := a + b
+		actual := myAdd(a, b)
+
+		require.Equal(t, expect, actual, "Expect %d + %d = %d", a, b, expect)
+	})
+}
+
+func myAdd(a, b int) int {
+	// Force myAdd to return the wrong sum if a is an odd number.
+	if a%2 != 0 {
+		return a + b + 1
+	}
+	return a + b
+}