test: add coverage for getExternalLinkUrl

Author: Taylor Payne

src/getExternalLinkUrl.test.js

@@ -0,0 +1,76 @@
+import { getExternalLinkUrl, setConfig } from './config';
+
+describe('getExternalLinkUrl', () => {
+  afterEach(() => {
+    // Reset config after each test to avoid cross-test pollution
+    setConfig({});
+  });
+
+  it('should return the url passed in when externalLinkUrlOverrides is not set', () => {
+    setConfig({});
+    const url = 'https://foo.example.com';
+    expect(getExternalLinkUrl(url)).toBe(url);
+  });
+
+  it('should return the url passed in when externalLinkUrlOverrides does not have the url mapping', () => {
+    setConfig({
+      externalLinkUrlOverrides: {
+        'https://bar.example.com': 'https://mapped.example.com',
+      },
+    });
+    const url = 'https://foo.example.com';
+    expect(getExternalLinkUrl(url)).toBe(url);
+  });
+
+  it('should return the mapped url when externalLinkUrlOverrides has the url mapping', () => {
+    const url = 'https://foo.example.com';
+    const mappedUrl = 'https://mapped.example.com';
+    setConfig({ externalLinkUrlOverrides: { [url]: mappedUrl } });
+    expect(getExternalLinkUrl(url)).toBe(mappedUrl);
+  });
+
+  it('should handle empty externalLinkUrlOverrides object', () => {
+    setConfig({ externalLinkUrlOverrides: {} });
+    const url = 'https://foo.example.com';
+    expect(getExternalLinkUrl(url)).toBe(url);
+  });
+
+  it('should guard against empty string argument', () => {
+    const fallbackResult = '#';
+    setConfig({ externalLinkUrlOverrides: { foo: 'bar' } });
+    expect(getExternalLinkUrl(undefined)).toBe(fallbackResult);
+  });
+
+  it('should guard against non-string argument', () => {
+    const fallbackResult = '#';
+    setConfig({ externalLinkUrlOverrides: { foo: 'bar' } });
+    expect(getExternalLinkUrl(null)).toBe(fallbackResult);
+    expect(getExternalLinkUrl(42)).toBe(fallbackResult);
+  });
+
+  it('should not throw if externalLinkUrlOverrides is not an object', () => {
+    setConfig({ externalLinkUrlOverrides: null });
+    const url = 'https://foo.example.com';
+    expect(getExternalLinkUrl(url)).toBe(url);
+    setConfig({ externalLinkUrlOverrides: 42 });
+    expect(getExternalLinkUrl(url)).toBe(url);
+  });
+
+  it('should work with multiple mappings', () => {
+    setConfig({
+      externalLinkUrlOverrides: {
+        'https://a.example.com': 'https://mapped-a.example.com',
+        'https://b.example.com': 'https://mapped-b.example.com',
+      },
+    });
+    expect(getExternalLinkUrl('https://a.example.com')).toBe(
+      'https://mapped-a.example.com',
+    );
+    expect(getExternalLinkUrl('https://b.example.com')).toBe(
+      'https://mapped-b.example.com',
+    );
+    expect(getExternalLinkUrl('https://c.example.com')).toBe(
+      'https://c.example.com',
+    );
+  });
+});