feat: add blocklist option

Sometimes people will work around not providing a proper reproduction
by adding any GitHub link.

This new option lets you disallow some potentially invalid links
like a simple fork of an example.

action.yml

@@ -18,6 +18,9 @@ inputs:
   reproduction-hosts:
     description: 'Comma-separated list of hostnames that are allowed for reproductions. Example: "github.com,codesandbox.io"'
     default: github.com
+  reproduction-blocklist:
+    description: 'Comma-separated list of URLs that are not allowed for reproductions. They can be regular expression string. Example: "github.com/.*/fork-of-example"'
+    default: ''
   reproduction-invalid-label:
     description: 'Label to apply to issues without a valid reproduction. Example: "invalid-reproduction"'
     default: 'invalid-reproduction'
@@ -64,6 +67,7 @@ runs:
         "INPUT_LABEL_COMMENTS": ${{inputs.label-comments}}
         "INPUT_REPRODUCTION_COMMENT": ${{inputs.reproduction-comment}}
         "INPUT_REPRODUCTION_HOSTS": ${{inputs.reproduction-hosts}}
+        "INPUT_REPRODUCTION_BLOCKLIST": ${{inputs.reproduction-blocklist}}
         "INPUT_REPRODUCTION_INVALID_LABEL": ${{inputs.reproduction-invalid-label}}
         "INPUT_REPRODUCTION_ISSUE_LABELS": ${{inputs.reproduction-issue-labels}}
         "INPUT_REPRODUCTION_LINK_SECTION": ${{inputs.reproduction-link-section}}

index.js

@@ -40,6 +40,9 @@ const config = {
     hosts: (getInput("reproduction_hosts") || "github.com")
       .split(",")
       .map((h) => h.trim()),
+    blocklist: (getInput("reproduction_blocklist") || "")
+      .split(",")
+      .map((h) => new RegExp(h.trim())),
     label: getInput("reproduction_invalid_label") || "invalid-reproduction",
     linkSection:
       getInput("reproduction_link_section") ||
@@ -121,7 +124,9 @@ async function checkValidReproduction() {
 }
 
 /**
- * Determine if an issue contains a valid/accessible link to a reproduction
+ * Determine if an issue contains a valid/accessible link to a reproduction.
+ *
+ * Returns `true` if the link is valid.
  * @param {string} body
  */
 async function isValidReproduction(body) {
@@ -140,6 +145,9 @@ async function isValidReproduction(body) {
   if (!config.invalidLink.hosts.includes(url.hostname))
     return info("Link did not match allowed reproduction hosts")
 
+  if (config.invalidLink.blocklist.some((r) => r.test(link)))
+    return info("Link matched blocklist for reproduction URLs")
+
   try {
     // Verify that the link can be opened
     // We allow 500, in case it's a downtime