From e2e84edf7b500a60e9fa0faf6da852160947cc8c Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Fri, 26 Jul 2024 17:25:44 +0200
Subject: [PATCH] frontend-plugin-api: add v2 extension and resolution

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
---
 .../wiring/resolveExtensionDefinition.test.ts | 54 +++++++++++++---
 .../src/wiring/resolveExtensionDefinition.ts  | 63 ++++++++++++++-----
 2 files changed, 93 insertions(+), 24 deletions(-)

diff --git a/packages/frontend-plugin-api/src/wiring/resolveExtensionDefinition.test.ts b/packages/frontend-plugin-api/src/wiring/resolveExtensionDefinition.test.ts
index 8970cfe168..e1bfcbfc11 100644
--- a/packages/frontend-plugin-api/src/wiring/resolveExtensionDefinition.test.ts
+++ b/packages/frontend-plugin-api/src/wiring/resolveExtensionDefinition.test.ts
@@ -17,14 +17,54 @@
 import { ExtensionDefinition } from './createExtension';
 import { resolveExtensionDefinition } from './resolveExtensionDefinition';
 
-const baseDef = {
-  $$type: '@backstage/ExtensionDefinition',
-  version: 'v1',
-  attachTo: { id: '', input: '' },
-  disabled: false,
-};
-
 describe('resolveExtensionDefinition', () => {
+  const baseDef = {
+    $$type: '@backstage/ExtensionDefinition',
+    version: 'v2',
+    attachTo: { id: '', input: '' },
+    disabled: false,
+  };
+
+  it.each([
+    [{ namespace: 'ns' }, 'ns'],
+    [{ namespace: 'n' }, 'n'],
+    [{ namespace: 'ns', name: 'n' }, 'ns/n'],
+    [{ kind: 'k', namespace: 'ns' }, 'k:ns'],
+    [{ kind: 'k', namespace: 'ns', name: 'n' }, 'k:ns/n'],
+  ])(`should resolve extension IDs %s`, (definition, expected) => {
+    const resolved = resolveExtensionDefinition({
+      ...baseDef,
+      ...definition,
+    } as ExtensionDefinition<unknown>);
+    expect(resolved.id).toBe(expected);
+    expect(String(resolved)).toBe(`Extension{id=${expected}}`);
+  });
+
+  it('should fail to resolve extension ID without namespace', () => {
+    expect(() =>
+      resolveExtensionDefinition({
+        ...baseDef,
+        kind: 'k',
+      } as ExtensionDefinition<unknown>),
+    ).toThrow(
+      'Extension must declare an explicit namespace or name as it could not be resolved from context, kind=k namespace=undefined name=undefined',
+    );
+    expect(() =>
+      resolveExtensionDefinition(baseDef as ExtensionDefinition<unknown>),
+    ).toThrow(
+      'Extension must declare an explicit namespace or name as it could not be resolved from context, kind=undefined namespace=undefined name=undefined',
+    );
+  });
+});
+
+describe('old resolveExtensionDefinition', () => {
+  const baseDef = {
+    $$type: '@backstage/ExtensionDefinition',
+    version: 'v1',
+    attachTo: { id: '', input: '' },
+    disabled: false,
+  };
+
   it.each([
     [{ namespace: 'ns' }, 'ns'],
     [{ namespace: 'n' }, 'n'],
diff --git a/packages/frontend-plugin-api/src/wiring/resolveExtensionDefinition.ts b/packages/frontend-plugin-api/src/wiring/resolveExtensionDefinition.ts
index eddd923702..18b6f0a653 100644
--- a/packages/frontend-plugin-api/src/wiring/resolveExtensionDefinition.ts
+++ b/packages/frontend-plugin-api/src/wiring/resolveExtensionDefinition.ts
@@ -24,6 +24,11 @@ import {
   toInternalExtensionDefinition,
 } from './createExtension';
 import { PortableSchema } from '../schema';
+import { ExtensionInput } from './createExtensionInput';
+import {
+  AnyExtensionDataRef,
+  ExtensionDataValue,
+} from './createExtensionDataRef';
 
 /** @public */
 export interface Extension<TConfig, TConfigInput = TConfig> {
@@ -35,17 +40,42 @@ export interface Extension<TConfig, TConfigInput = TConfig> {
 }
 
 /** @internal */
-export interface InternalExtension<TConfig, TConfigInput>
-  extends Extension<TConfig, TConfigInput> {
-  readonly version: 'v1';
-  readonly inputs: AnyExtensionInputMap;
-  readonly output: AnyExtensionDataMap;
-  factory(options: {
-    node: AppNode;
-    config: TConfig;
-    inputs: ResolvedExtensionInputs<any>;
-  }): ExtensionDataValues<any>;
-}
+export type InternalExtension<TConfig, TConfigInput> = Extension<
+  TConfig,
+  TConfigInput
+> &
+  (
+    | {
+        readonly version: 'v1';
+        readonly inputs: AnyExtensionInputMap;
+        readonly output: AnyExtensionDataMap;
+        factory(options: {
+          node: AppNode;
+          config: TConfig;
+          inputs: ResolvedExtensionInputs<AnyExtensionInputMap>;
+        }): ExtensionDataValues<any>;
+      }
+    | {
+        readonly version: 'v2';
+        readonly inputs: {
+          [inputName in string]: ExtensionInput<
+            AnyExtensionDataRef,
+            { optional: boolean; singleton: boolean }
+          >;
+        };
+        readonly output: Array<AnyExtensionDataRef>;
+        factory(options: {
+          node: AppNode;
+          config: TConfig;
+          inputs: ResolvedExtensionInputs<{
+            [inputName in string]: ExtensionInput<
+              AnyExtensionDataRef,
+              { optional: boolean; singleton: boolean }
+            >;
+          }>;
+        }): Iterable<ExtensionDataValue<any, any>>;
+      }
+  );
 
 /** @internal */
 export function toInternalExtension<TConfig, TConfigInput>(
@@ -57,10 +87,9 @@ export function toInternalExtension<TConfig, TConfigInput>(
       `Invalid extension instance, bad type '${internal.$$type}'`,
     );
   }
-  if (internal.version !== 'v1') {
-    throw new Error(
-      `Invalid extension instance, bad version '${internal.version}'`,
-    );
+  const version = internal.version;
+  if (version !== 'v1' && version !== 'v2') {
+    throw new Error(`Invalid extension instance, bad version '${version}'`);
   }
   return internal;
 }
@@ -87,10 +116,10 @@ export function resolveExtensionDefinition<TConfig, TConfigInput>(
   return {
     ...rest,
     $$type: '@backstage/Extension',
-    version: 'v1',
+    version: internalDefinition.version,
     id,
     toString() {
       return `Extension{id=${id}}`;
     },
-  } as Extension<TConfig, TConfigInput>;
+  } as InternalExtension<TConfig, TConfigInput>;
 }