Fix traces for default export (resolves #860)

packages/knip/fixtures/trace/default.ts

@@ -0,0 +1,3 @@
+export default function DefaultComponent() {
+  return '';
+}

packages/knip/fixtures/trace/index.ts

@@ -0,0 +1 @@
+export { MyPage } from './my-page';

packages/knip/fixtures/trace/my-page.ts

@@ -0,0 +1,7 @@
+import { NamedComponent } from './named';
+import DefaultComponent from './default';
+
+export const MyPage = () => {
+  NamedComponent();
+  DefaultComponent();
+};

packages/knip/fixtures/trace/named.ts

@@ -0,0 +1,3 @@
+export function NamedComponent() {
+  return '';
+}

packages/knip/fixtures/trace/package.json

@@ -0,0 +1,3 @@
+{
+  "name": "@fixtures/trace"
+}

packages/knip/src/util/is-identifier-referenced.ts

@@ -38,7 +38,11 @@ export const getIsIdentifierReferencedHandler = (graph: DependencyGraph, entryPa
     ) {
       isReferenced = true;
       if (!isTrace) return { isReferenced, reExportingEntryFile, traceNode };
-      addNodes(traceNode, id, graph, file.imported.get(identifier));
+      if (file.importedAs.has(identifier)) {
+        for (const aliases of file.importedAs.values()) {
+          for (const alias of aliases.keys()) addNodes(traceNode, alias, graph, aliases.get(alias));
+        }
+      } else addNodes(traceNode, id, graph, file.imported.get(identifier));
     }
 
     for (const [exportId, aliases] of file.importedAs.entries()) {
@@ -47,7 +51,9 @@ export const getIsIdentifierReferencedHandler = (graph: DependencyGraph, entryPa
           const aliasedRef = [alias, ...rest].join('.');
           if (file.refs.has(aliasedRef)) {
             isReferenced = true;
-            if (!isTrace) return { isReferenced, reExportingEntryFile, traceNode };
+            if (!isTrace) {
+              return { isReferenced, reExportingEntryFile, traceNode };
+            }
             addNodes(traceNode, aliasedRef, graph, aliases.get(alias));
           }
         }

packages/knip/test/trace.test.ts

@@ -0,0 +1,23 @@
+import { test } from 'bun:test';
+import assert from 'node:assert/strict';
+import { main } from '../src/index.js';
+import { resolve } from '../src/util/path.js';
+import baseArguments from './helpers/baseArguments.js';
+import baseCounters from './helpers/baseCounters.js';
+
+test('Trace', async () => {
+  const cwd = resolve('fixtures/trace');
+
+  const { counters } = await main({
+    ...baseArguments,
+    cwd,
+  });
+
+  // TODO Should either get traces from main or assert stdout output through cli
+
+  assert.deepEqual(counters, {
+    ...baseCounters,
+    processed: 4,
+    total: 4,
+  });
+});