fix(matchers): toHaveClass on SVG elements (#15267)

Fixes #15260

packages/playwright-core/src/server/injected/injectedScript.ts

@@ -1071,7 +1071,7 @@ export class InjectedScript {
       if (expression === 'to.have.attribute') {
         received = element.getAttribute(options.expressionArg) || '';
       } else if (expression === 'to.have.class') {
-        received = element.className;
+        received = element.classList.toString();
       } else if (expression === 'to.have.css') {
         received = window.getComputedStyle(element).getPropertyValue(options.expressionArg);
       } else if (expression === 'to.have.id') {
@@ -1112,7 +1112,7 @@ export class InjectedScript {
     if (expression === 'to.have.text.array' || expression === 'to.contain.text.array')
       received = elements.map(e => options.useInnerText ? (e as HTMLElement).innerText : e.textContent || '');
     else if (expression === 'to.have.class.array')
-      received = elements.map(e => e.className);
+      received = elements.map(e => e.classList.toString());
 
     if (received && options.expectedText) {
       // "To match an array" is "to contain an array" + "equal length"

tests/playwright-test/playwright.expect.misc.spec.ts

@@ -216,6 +216,11 @@ test('should support toHaveClass', async ({ runInlineTest }) => {
         await expect(locator).toHaveClass('foo bar baz');
       });
 
+      test('pass with SVGs', async ({ page }) => {
+        await page.setContent(\`<svg class="c1 c2" role="img" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512"></svg>\`);
+        await expect(page.locator('svg')).toHaveClass(/c1/);
+      });
+
       test('fail', async ({ page }) => {
         await page.setContent('<div class="bar baz"></div>');
         const locator = page.locator('div');
@@ -226,7 +231,7 @@ test('should support toHaveClass', async ({ runInlineTest }) => {
   const output = stripAnsi(result.output);
   expect(output).toContain('expect(locator).toHaveClass');
   expect(output).toContain('Expected string: \"foo bar baz\"');
-  expect(result.passed).toBe(1);
+  expect(result.passed).toBe(2);
   expect(result.failed).toBe(1);
   expect(result.exitCode).toBe(1);
 });