frontend-app-api: always shunt mentioned extensions to the top

Signed-off-by: Fredrik Adelöw <freben@gmail.com>

.changeset/lazy-phones-worry.md

@@ -0,0 +1,5 @@
+---
+'@backstage/frontend-app-api': minor
+---
+
+Extensions in app-config now always affect ordering. Previously, only when enabling disabled extensions did they rise to the top.

packages/frontend-app-api/src/tree/resolveAppNodeSpecs.test.ts

@@ -110,6 +110,12 @@ describe('resolveAppNodeSpecs', () => {
         ],
       }),
     ).toEqual([
+      {
+        id: 'b',
+        extension: b,
+        attachTo: { id: 'derp', input: 'default' },
+        disabled: false,
+      },
       {
         id: 'test/a',
         extension: makeExt('test/a'),
@@ -117,12 +123,6 @@ describe('resolveAppNodeSpecs', () => {
         source: pluginA,
         disabled: false,
       },
-      {
-        id: 'b',
-        extension: b,
-        attachTo: { id: 'derp', input: 'default' },
-        disabled: false,
-      },
     ]);
   });
 
@@ -206,6 +206,70 @@ describe('resolveAppNodeSpecs', () => {
     ]);
   });
 
+  it('should place config-mentioned instances in the order that they were listed, irrespective of if the extension was enabled or not originally', () => {
+    const a = makeExt('a', 'disabled');
+    const b = makeExt('b', 'enabled');
+    const c = makeExt('c', 'disabled');
+    const d = makeExt('d', 'enabled');
+    const e = makeExt('e', 'disabled');
+    const f = makeExt('f', 'enabled');
+    const g = makeExt('g', 'disabled');
+    expect(
+      resolveAppNodeSpecs({
+        features: [createPlugin({ id: 'empty', extensions: [] })],
+        builtinExtensions: [a, b, c, d, e, f, g],
+        parameters: [
+          { id: 'e', disabled: false },
+          { id: 'd', disabled: false },
+          { id: 'c', disabled: false },
+        ],
+      }),
+    ).toEqual([
+      {
+        id: 'e',
+        extension: e,
+        attachTo: { id: 'root', input: 'default' },
+        disabled: false,
+      },
+      {
+        id: 'd',
+        extension: d,
+        attachTo: { id: 'root', input: 'default' },
+        disabled: false,
+      },
+      {
+        id: 'c',
+        extension: c,
+        attachTo: { id: 'root', input: 'default' },
+        disabled: false,
+      },
+      {
+        id: 'a',
+        extension: a,
+        attachTo: { id: 'root', input: 'default' },
+        disabled: true,
+      },
+      {
+        id: 'b',
+        extension: b,
+        attachTo: { id: 'root', input: 'default' },
+        disabled: false,
+      },
+      {
+        id: 'f',
+        extension: f,
+        attachTo: { id: 'root', input: 'default' },
+        disabled: false,
+      },
+      {
+        id: 'g',
+        extension: g,
+        attachTo: { id: 'root', input: 'default' },
+        disabled: true,
+      },
+    ]);
+  });
+
   it('should apply extension overrides', () => {
     const plugin = createPlugin({
       id: 'test',

packages/frontend-app-api/src/tree/resolveAppNodeSpecs.ts

@@ -184,6 +184,7 @@ export function resolveAppNodeSpecs(options: {
     );
   }
 
+  const order = new Map<string, (typeof configuredExtensions)[number]>();
   for (const overrideParam of parameters) {
     const extensionId = overrideParam.id;
 
@@ -193,11 +194,10 @@ export function resolveAppNodeSpecs(options: {
       );
     }
 
-    const existingIndex = configuredExtensions.findIndex(
+    const existing = configuredExtensions.find(
       e => e.extension.id === extensionId,
     );
-    if (existingIndex !== -1) {
-      const existing = configuredExtensions[existingIndex];
+    if (existing) {
       if (overrideParam.attachTo) {
         existing.params.attachTo = overrideParam.attachTo;
       }
@@ -209,18 +209,19 @@ export function resolveAppNodeSpecs(options: {
         Boolean(existing.params.disabled) !== Boolean(overrideParam.disabled)
       ) {
         existing.params.disabled = Boolean(overrideParam.disabled);
-        if (!existing.params.disabled) {
-          // bump
-          configuredExtensions.splice(existingIndex, 1);
-          configuredExtensions.push(existing);
-        }
       }
+      order.set(extensionId, existing);
     } else {
       throw new Error(`Extension ${extensionId} does not exist`);
     }
   }
 
-  return configuredExtensions.map(param => ({
+  const orderedExtensions = [
+    ...order.values(),
+    ...configuredExtensions.filter(e => !order.has(e.extension.id)),
+  ];
+
+  return orderedExtensions.map(param => ({
     id: param.extension.id,
     attachTo: param.params.attachTo,
     extension: param.extension,

packages/frontend-plugin-api/src/wiring/createPlugin.test.ts

@@ -187,7 +187,7 @@ describe('createPlugin', () => {
 
     await expect(
       screen.findByText(
-        'Names: extension-1, extension-2-renamed, extension-3:child',
+        'Names: extension-2-renamed, extension-1, extension-3:child',
       ),
     ).resolves.toBeInTheDocument();
   });