From f86bd410e658f03b644fb7c3b3fee4383cac2935 Mon Sep 17 00:00:00 2001
From: Camila Belo <camilaibs@gmail.com>
Date: Wed, 20 Sep 2023 11:10:09 +0200
Subject: [PATCH] refactor(frontend-app-api): to inline validation

Signed-off-by: Camila Belo <camilaibs@gmail.com>
---
 .../frontend-app-api/src/wiring/createApp.tsx | 42 ++++---------------
 .../frontend-app-api/src/wiring/parameters.ts | 17 ++++----
 2 files changed, 17 insertions(+), 42 deletions(-)

diff --git a/packages/frontend-app-api/src/wiring/createApp.tsx b/packages/frontend-app-api/src/wiring/createApp.tsx
index bc16fd9559..abd135cc5f 100644
--- a/packages/frontend-app-api/src/wiring/createApp.tsx
+++ b/packages/frontend-app-api/src/wiring/createApp.tsx
@@ -161,38 +161,6 @@ export function createExtensionTree(options: {
   };
 }
 
-function hasCyclicalExtensionDependency(
-  extensionId: string,
-  extensionAncestorIds: string[] = [],
-) {
-  return extensionAncestorIds.includes(extensionId);
-}
-
-function stringifyExtensionDependencyGraph(
-  extensionId: string,
-  extensionAncestorIds: string[] = [],
-) {
-  const [rootAncestorId, ...rest] = extensionAncestorIds.concat(extensionId);
-  return rest.reduce((graphString, ancestorId) => {
-    return `${graphString} → ${ancestorId}`;
-  }, rootAncestorId);
-}
-
-function preventCyclicalExtensionDependency(
-  extensionId: string,
-  extensionAncestorIds: string[],
-) {
-  if (hasCyclicalExtensionDependency(extensionId, extensionAncestorIds)) {
-    const extensionDependencyGraph = stringifyExtensionDependencyGraph(
-      extensionId,
-      extensionAncestorIds,
-    );
-    throw new Error(
-      `There is a cyclical dependency with the extension "${extensionId}": ${extensionDependencyGraph}`,
-    );
-  }
-}
-
 /**
  * @internal
  */
@@ -248,7 +216,15 @@ export function createInstances(options: {
       return existingInstance;
     }
 
-    preventCyclicalExtensionDependency(extensionId, extensionAncestorIds);
+    // Prevent cyclical dependencies
+    if (extensionAncestorIds.includes(extensionId)) {
+      const extensionDependencyGraph = extensionAncestorIds
+        .concat(extensionId)
+        .join(' → ');
+      throw new Error(
+        `There is a cyclical dependency with the extension "${extensionId}": ${extensionDependencyGraph}`,
+      );
+    }
 
     const attachments = new Map(
       Array.from(attachmentMap.get(extensionId)?.entries() ?? []).map(
diff --git a/packages/frontend-app-api/src/wiring/parameters.ts b/packages/frontend-app-api/src/wiring/parameters.ts
index acde9d9ec0..b18853ab5c 100644
--- a/packages/frontend-app-api/src/wiring/parameters.ts
+++ b/packages/frontend-app-api/src/wiring/parameters.ts
@@ -188,14 +188,6 @@ export interface ExtensionInstanceParameters {
   config?: unknown;
 }
 
-function preventRootExtensionOverride(id: string) {
-  if (id === 'root') {
-    throw new Error(
-      'There is a root extension in the app config file and root extensions are not configurable',
-    );
-  }
-}
-
 /** @internal */
 export function mergeExtensionParameters(options: {
   sources: BackstagePlugin[];
@@ -229,7 +221,14 @@ export function mergeExtensionParameters(options: {
 
   for (const overrideParam of parameters) {
     const extensionId = overrideParam.id;
-    preventRootExtensionOverride(extensionId);
+
+    // Prevent root parametrization
+    if (extensionId === 'root') {
+      throw new Error(
+        'There is a root extension in the app config file and root extensions are not configurable',
+      );
+    }
+
     const existingIndex = overrides.findIndex(
       e => e.extension.id === extensionId,
     );