Handle globalAgent having a single non-array CA (#6628)

* Handle globalAgent having a single non-array CA

Signed-off-by: Sebastian Malton <sebastian@malton.name>

* Rewrite ternary as IIFE

Signed-off-by: Sebastian Malton <sebastian@malton.name>

Signed-off-by: Sebastian Malton <sebastian@malton.name>

src/common/certificate-authorities/inject-system-cas.injectable.ts

@@ -22,15 +22,36 @@ const injectSystemCAsInjectable = getInjectable({
     const requestSystemCAs = di.inject(requestSystemCAsInjectionToken);
 
     return async () => {
-      for (const cert of await requestSystemCAs()) {
-        if (isCertActive(cert)) {
-          if (Array.isArray(globalAgent.options.ca) && !globalAgent.options.ca.includes(cert)) {
-            globalAgent.options.ca.push(cert);
-          } else {
-            globalAgent.options.ca = [cert];
-          }
+      const certs = await requestSystemCAs();
+
+      if (certs.length === 0) {
+        // Leave the global option alone
+        return;
+      }
+
+      const cas = (() => {
+        if (Array.isArray(globalAgent.options.ca)) {
+          return globalAgent.options.ca;
+        }
+
+        if (globalAgent.options.ca) {
+          return [globalAgent.options.ca];
+        }
+
+        return [];
+      })();
+
+      for (const cert of certs) {
+        if (!isCertActive(cert)) {
+          continue;
+        }
+
+        if (!cas.includes(cert)) {
+          cas.push(cert);
         }
       }
+
+      globalAgent.options.ca = cas;
     };
   },
 });