test(ExportPanel-type-compiler): verify TypeScript Compiler Validation & Schema Constraints Stability

app/customize/components/ExportPanel.type-compiler.test.tsx

@@ -0,0 +1,66 @@
+import { describe, it, expectTypeOf } from 'vitest';
+import type { ComponentProps } from 'react';
+import type { ExportFormat } from '../types';
+import { ExportPanel } from './ExportPanel';
+
+describe('ExportPanel TypeScript compiler validation & schema constraints', () => {
+  it('ExportFormat accepts only "markdown" | "html" | "action" | "tsx" and rejects other literals', () => {
+    expectTypeOf<ExportFormat>().toEqualTypeOf<'markdown' | 'html' | 'action' | 'tsx'>();
+
+    // @ts-expect-error - 'pdf' is not a member of the ExportFormat union
+    const invalidFormat: ExportFormat = 'pdf';
+    void invalidFormat;
+  });
+
+  it('onFormatChange must be typed as (format: ExportFormat) => void, rejecting an incompatible callback signature', () => {
+    type Props = ComponentProps<typeof ExportPanel>;
+    expectTypeOf<Props['onFormatChange']>().toEqualTypeOf<(format: ExportFormat) => void>();
+
+    const invalidHandler: Props['onFormatChange'] = (format: string) => {
+      void format;
+    };
+    void invalidHandler;
+  });
+
+  it('onCopy accepts either a sync (void) or an async (Promise<void>) function without a compile error', () => {
+    type Props = ComponentProps<typeof ExportPanel>;
+    expectTypeOf<Props['onCopy']>().toEqualTypeOf<() => void | Promise<void>>();
+
+    const syncHandler: Props['onCopy'] = () => {};
+    const asyncHandler: Props['onCopy'] = async () => {
+      await Promise.resolve();
+    };
+    expectTypeOf(syncHandler).toEqualTypeOf<() => void | Promise<void>>();
+    expectTypeOf(asyncHandler).toEqualTypeOf<() => void | Promise<void>>();
+  });
+
+  it('every ExportPanel prop is required, omitting any one is rejected at compile time', () => {
+    type Props = ComponentProps<typeof ExportPanel>;
+
+    expectTypeOf<Props['format']>().not.toBeUndefined();
+    expectTypeOf<Props['snippet']>().toEqualTypeOf<string>();
+    expectTypeOf<Props['hasUsername']>().toEqualTypeOf<boolean>();
+
+    // @ts-expect-error - `username` is missing, which is a compile error since it's required
+    const incompleteProps: Props = {
+      format: 'markdown',
+      snippet: '',
+      copied: false,
+      copyStatusMessage: '',
+      hasUsername: true,
+      onFormatChange: () => {},
+      onCopy: () => {},
+    };
+    void incompleteProps;
+  });
+
+  it('copied and hasUsername are strictly boolean, rejecting truthy/falsy stand-ins like 0, 1, or string values', () => {
+    type Props = ComponentProps<typeof ExportPanel>;
+    expectTypeOf<Props['copied']>().toEqualTypeOf<boolean>();
+    expectTypeOf<Props['hasUsername']>().toEqualTypeOf<boolean>();
+
+    // @ts-expect-error - 1 is a number, not assignable to boolean
+    const invalidCopied: Props['copied'] = 1;
+    void invalidCopied;
+  });
+});