Added new feature for document export, including API contracts, data model, implementation plan, and tests. Updated related configurations and instructions.

tests/unit/format-selection.test.js

@@ -0,0 +1,127 @@
+/**
+ * Unit Tests: Format Selection Logic
+ * 
+ * Tests the selectExportFormat helper function
+ * Verifies priority ordering: Markdown > HTML > PDF
+ */
+
+import { describe, it } from 'node:test';
+import assert from 'node:assert';
+
+// Load helper functions using vm.Script pattern (similar to proxy.js)
+import { readFileSync } from 'fs';
+import { Script } from 'vm';
+
+// Create VM context with required globals
+const vmContext = {
+  crypto: globalThis.crypto,
+  console: console
+};
+
+// Load googleDriveAdapterHelper.js
+const helperCode = readFileSync('./src/globalVariables/googleDriveAdapterHelper.js', 'utf8');
+const wrappedCode = `(function() {\n${helperCode}\n})()`;
+const script = new Script(wrappedCode);
+const helpers = script.runInNewContext(vmContext);
+
+describe('Format Selection', () => {
+  describe('selectExportFormat', () => {
+    it('should prioritize text/x-markdown over other formats', () => {
+      const exportLinks = {
+        'text/x-markdown': 'https://example.com/export?format=md',
+        'text/html': 'https://example.com/export?format=html',
+        'application/pdf': 'https://example.com/export?format=pdf'
+      };
+
+      const result = helpers.selectExportFormat(exportLinks);
+
+      assert.strictEqual(result.contentType, 'text/x-markdown');
+      assert.strictEqual(result.extension, 'md');
+      assert.strictEqual(result.url, 'https://example.com/export?format=md');
+    });
+
+    it('should select text/html when markdown is unavailable', () => {
+      const exportLinks = {
+        'text/html': 'https://example.com/export?format=html',
+        'application/pdf': 'https://example.com/export?format=pdf'
+      };
+
+      const result = helpers.selectExportFormat(exportLinks);
+
+      assert.strictEqual(result.contentType, 'text/html');
+      assert.strictEqual(result.extension, 'html');
+      assert.strictEqual(result.url, 'https://example.com/export?format=html');
+    });
+
+    it('should select application/pdf when markdown and html are unavailable', () => {
+      const exportLinks = {
+        'application/pdf': 'https://example.com/export?format=pdf'
+      };
+
+      const result = helpers.selectExportFormat(exportLinks);
+
+      assert.strictEqual(result.contentType, 'application/pdf');
+      assert.strictEqual(result.extension, 'pdf');
+      assert.strictEqual(result.url, 'https://example.com/export?format=pdf');
+    });
+
+    it('should return null when no supported formats are available', () => {
+      const exportLinks = {
+        'text/plain': 'https://example.com/export?format=txt',
+        'application/json': 'https://example.com/export?format=json'
+      };
+
+      const result = helpers.selectExportFormat(exportLinks);
+
+      assert.strictEqual(result, null);
+    });
+
+    it('should return null when exportLinks is null', () => {
+      const result = helpers.selectExportFormat(null);
+
+      assert.strictEqual(result, null);
+    });
+
+    it('should return null when exportLinks is undefined', () => {
+      const result = helpers.selectExportFormat(undefined);
+
+      assert.strictEqual(result, null);
+    });
+
+    it('should return null when exportLinks is empty object', () => {
+      const result = helpers.selectExportFormat({});
+
+      assert.strictEqual(result, null);
+    });
+
+    it('should respect priority order even when formats appear in different order', () => {
+      const exportLinks = {
+        'application/pdf': 'https://example.com/export?format=pdf',
+        'text/x-markdown': 'https://example.com/export?format=md',
+        'text/html': 'https://example.com/export?format=html'
+      };
+
+      const result = helpers.selectExportFormat(exportLinks);
+
+      // Should still select Markdown despite PDF being first in object
+      assert.strictEqual(result.contentType, 'text/x-markdown');
+    });
+  });
+
+  describe('EXPORT_FORMATS constant', () => {
+    it('should define correct priority order', () => {
+      assert.ok(Array.isArray(helpers.EXPORT_FORMATS));
+      assert.strictEqual(helpers.EXPORT_FORMATS.length, 3);
+      
+      // Verify order: Markdown > HTML > PDF
+      assert.strictEqual(helpers.EXPORT_FORMATS[0].mimeType, 'text/x-markdown');
+      assert.strictEqual(helpers.EXPORT_FORMATS[0].extension, 'md');
+      
+      assert.strictEqual(helpers.EXPORT_FORMATS[1].mimeType, 'text/html');
+      assert.strictEqual(helpers.EXPORT_FORMATS[1].extension, 'html');
+      
+      assert.strictEqual(helpers.EXPORT_FORMATS[2].mimeType, 'application/pdf');
+      assert.strictEqual(helpers.EXPORT_FORMATS[2].extension, 'pdf');
+    });
+  });
+});