Fix npm.isCollaborator() on npm v9 (#966)

With v9.0.0 release [npm][] has changed the CLI commands for package
access. While previously it was `npm access ls-collaborators` and the
output was a JSON object, now it is `npm access list collaborators` and
the output is plain text unless `--json` flag is provided.

This commit adds support for npm v9.0.0 while keeping support for older
npm versions.

[npm]: npm/cli@9c32c6c

lib/plugin/npm/npm.js

@@ -132,34 +132,43 @@ class npm extends Plugin {
     );
   }
 
-  isCollaborator() {
+  async isCollaborator() {
     const registry = this.getRegistry();
     const registryArg = registry ? ` --registry ${registry}` : '';
     const name = this.getName();
     const { username } = this.getContext();
     if (username === undefined) return true;
     if (username === null) return false;
-    return this.exec(`npm access ls-collaborators ${name}${registryArg}`, { options }).then(
-      output => {
-        try {
-          const collaborators = JSON.parse(output);
-          const permissions = collaborators[username];
-          return permissions && permissions.includes('write');
-        } catch (err) {
-          this.debug(err);
-          return false;
-        }
-      },
-      err => {
+
+    try {
+      let npmVersion = await this.exec('npm --version', { options });
+
+      let accessCommand;
+      if (semver.gt(npmVersion, '9.0.0')) {
+        accessCommand = 'npm access list collaborators --json';
+      } else {
+        accessCommand = 'npm access ls-collaborators';
+      }
+
+      const output = await this.exec(`${accessCommand} ${name}${registryArg}`, { options });
+
+      try {
+        const collaborators = JSON.parse(output);
+        const permissions = collaborators[username];
+        return permissions && permissions.includes('write');
+      } catch (err) {
         this.debug(err);
-        if (/code E400/.test(err)) {
-          this.log.warn('Ignoring response from unsupported `npm access` command.');
-        } else {
-          this.log.warn(`Unable to verify if user ${username} is a collaborator for ${name}.`);
-        }
-        return true;
+        return false;
       }
-    );
+    } catch (err) {
+      this.debug(err);
+      if (/code E400/.test(err)) {
+        this.log.warn('Ignoring response from unsupported `npm access` command.');
+      } else {
+        this.log.warn(`Unable to verify if user ${username} is a collaborator for ${name}.`);
+      }
+      return true;
+    }
   }
 
   async getLatestRegistryVersion() {