feat: Create ChainedTemplateEngine for combining engines

config/identity/handler/default.json

@@ -23,7 +23,22 @@
       "providerFactory": { "@id": "urn:solid-server:default:IdentityProviderFactory" },
       "templateHandler": {
         "@type": "TemplateHandler",
-        "templateEngine": { "@type": "EjsTemplateEngine" }
+        "templateEngine": {
+          "comment": "Renders the specific page and embeds it into the main HTML body.",
+          "@type": "ChainedTemplateEngine",
+          "renderedName": "htmlBody",
+          "engines": [
+            {
+              "comment": "Will be called with specific interaction templates to generate HTML snippets.",
+              "@type": "EjsTemplateEngine"
+            },
+            {
+              "comment": "Will embed the result of the first engine into the main HTML template.",
+              "@type": "EjsTemplateEngine",
+              "template": "$PACKAGE_ROOT/templates/main.html.ejs",
+            }
+          ]
+        }
       },
       "interactionCompleter": {
         "comment": "Responsible for finishing OIDC interactions.",

config/identity/handler/interaction/routes/forgot-password.json

@@ -7,7 +7,7 @@
       "@type": "InteractionRoute",
       "route": "^/forgotpassword/?$",
       "viewTemplate": "$PACKAGE_ROOT/templates/identity/email-password/forgot-password.html.ejs",
-      "responseTemplate": "$PACKAGE_ROOT/templates/identity/email-password/email-sent.html.ejs",
+      "responseTemplate": "$PACKAGE_ROOT/templates/identity/email-password/forgot-password-response.html.ejs",
       "handler": {
         "@type": "ForgotPasswordHandler",
         "args_accountStore": { "@id": "urn:solid-server:auth:password:AccountStore" },

config/identity/handler/interaction/routes/reset-password.json

@@ -8,7 +8,7 @@
       "@type": "InteractionRoute",
       "route": "^/resetpassword(/[^/]*)?$",
       "viewTemplate": "$PACKAGE_ROOT/templates/identity/email-password/reset-password.html.ejs",
-      "responseTemplate": "$PACKAGE_ROOT/templates/identity/email-password/message.html.ejs",
+      "responseTemplate": "$PACKAGE_ROOT/templates/identity/email-password/reset-password-response.html.ejs",
       "handler": {
         "@type": "ResetPasswordHandler",
         "accountStore": { "@id": "urn:solid-server:auth:password:AccountStore" }

config/util/representation-conversion/converters/markdown.json

@@ -11,8 +11,8 @@
       "@id": "urn:solid-server:default:MarkdownToHtmlConverter",
       "@type": "MarkdownToHtmlConverter",
       "templateEngine": {
-        "@type": "HandlebarsTemplateEngine",
+        "@type": "EjsTemplateEngine",
-        "template": "$PACKAGE_ROOT/templates/main.html.hbs"
+        "template": "$PACKAGE_ROOT/templates/main.html.ejs"
       }
     },
     {

src/identity/IdentityProviderHttpHandler.ts

@@ -182,9 +182,9 @@ export class IdentityProviderHttpHandler extends HttpHandler {
     throw new BadRequestHttpError(`Unsupported request: ${request.method} ${request.url}`);
   }
 
-  private async handleTemplateResponse(response: HttpResponse, templateFile: string, contents: NodeJS.Dict<any>):
+  private async handleTemplateResponse(response: HttpResponse, templateFile: string, contents?: NodeJS.Dict<any>):
   Promise<void> {
-    await this.templateHandler.handleSafe({ response, templateFile, contents });
+    await this.templateHandler.handleSafe({ response, templateFile, contents: contents ?? {}});
   }
 
   /**

src/identity/interaction/email-password/handler/InteractionHandler.ts

@@ -6,7 +6,7 @@ export type InteractionHandlerResult = InteractionResponseResult | InteractionCo
 
 export interface InteractionResponseResult<T = NodeJS.Dict<any>> {
   type: 'response';
-  details: T;
+  details?: T;
 }
 
 export interface InteractionCompleteResult {

src/identity/interaction/email-password/handler/ResetPasswordHandler.ts

@@ -34,7 +34,7 @@ export class ResetPasswordHandler extends InteractionHandler {
       assertPassword(password, confirmPassword);
 
       await this.resetPassword(recordId, password);
-      return { type: 'response', details: { message: 'Your password was successfully reset.' }};
+      return { type: 'response' };
     } catch (error: unknown) {
       throwIdpInteractionError(error);
     }

src/index.ts

@@ -304,6 +304,7 @@ export * from './util/locking/SingleThreadedResourceLocker';
 export * from './util/locking/WrappedExpiringReadWriteLocker';
 
 // Util/Templates
+export * from './util/templates/ChainedTemplateEngine';
 export * from './util/templates/EjsTemplateEngine';
 export * from './util/templates/HandlebarsTemplateEngine';
 export * from './util/templates/TemplateEngine';

src/storage/conversion/MarkdownToHtmlConverter.ts

@@ -23,12 +23,8 @@ export class MarkdownToHtmlConverter extends TypedRepresentationConverter {
 
   public async handle({ representation }: RepresentationConverterArgs): Promise<Representation> {
     const markdown = await readableToString(representation.data);
-    // Try to extract the main title for use in the <title> tag
-    const title = /^#+\s*([^\n]+)\n/u.exec(markdown)?.[1];
-
-    // Place the rendered Markdown into the HTML template
     const htmlBody = marked(markdown);
-    const html = await this.templateEngine.render({ htmlBody, title });
+    const html = await this.templateEngine.render({ htmlBody });
 
     return new BasicRepresentation(html, representation.metadata, TEXT_HTML);
   }

src/util/templates/ChainedTemplateEngine.ts

@@ -0,0 +1,39 @@
+import type { Template, TemplateEngine } from './TemplateEngine';
+import Dict = NodeJS.Dict;
+
+/**
+ * Calls the given array of {@link TemplateEngine}s in the order they appear,
+ * feeding the output of one into the input of the next.
+ *
+ * The first engine will be called with the provided contents and template parameters.
+ * All subsequent engines will be called with no template parameter.
+ * Contents will still be passed along and another entry will be added for the body of the previous output.
+ */
+export class ChainedTemplateEngine<T extends Dict<any> = Dict<any>> implements TemplateEngine<T> {
+  private readonly firstEngine: TemplateEngine<T>;
+  private readonly chainedEngines: TemplateEngine[];
+  private readonly renderedName: string;
+
+  /**
+   * @param engines - Engines will be executed in the same order as the array.
+   * @param renderedName - The name of the key used to pass the body of one engine to the next.
+   */
+  public constructor(engines: TemplateEngine[], renderedName = 'body') {
+    if (engines.length === 0) {
+      throw new Error('At least 1 engine needs to be provided.');
+    }
+    this.firstEngine = engines[0];
+    this.chainedEngines = engines.slice(1);
+    this.renderedName = renderedName;
+  }
+
+  public async render(contents: T): Promise<string>;
+  public async render<TCustom = T>(contents: TCustom, template: Template): Promise<string>;
+  public async render<TCustom = T>(contents: TCustom, template?: Template): Promise<string> {
+    let body = await this.firstEngine.render(contents, template!);
+    for (const engine of this.chainedEngines) {
+      body = await engine.render({ ...contents, [this.renderedName]: body });
+    }
+    return body;
+  }
+}

templates/identity/email-password/confirm.html.ejs

@@ -1,27 +1,4 @@
-<!DOCTYPE html>
+<h1>Authorize</h1>
-<html lang="en">
+<form action="/idp/confirm" method="post">
-<head>
-  <meta charset="utf-8"/>
-  <meta name="viewport" content="width=device-width, initial-scale=1"/>
-  <title>Authorize</title>
-  <link rel="stylesheet" href="/.well_known/css/styles/main.css" type="text/css">
-</head>
-<body>
-  <header>
-    <a href="/"><img src="/.well_known/css/images/solid.svg" alt="[Solid logo]" /></a>
-    <h1>Community Solid Server</h1>
-  </header>
-  <main>
-    <h1>Authorize</h1>
-    <form action="/idp/confirm" method="post">
   <p class="actions"><button autofocus type="submit" name="submit" class="ids-link-filled">Continue</button></p>
-    </form>
+</form>
-  </main>
-  <footer>
-    <p>
-      ©2019–2021 <a href="https://inrupt.com/">Inrupt Inc.</a>
-      and <a href="https://www.imec-int.com/">imec</a>
-    </p>
-  </footer>
-</body>
-</html>

templates/identity/email-password/email-sent.html.ejs

@@ -1,37 +0,0 @@
-<!DOCTYPE html>
-<html lang="en">
-<head>
-  <meta charset="utf-8"/>
-  <meta name="viewport" content="width=device-width, initial-scale=1"/>
-  <title>Email sent</title>
-  <link rel="stylesheet" href="/.well_known/css/styles/main.css" type="text/css">
-</head>
-<body>
-  <header>
-    <a href="/"><img src="/.well_known/css/images/solid.svg" alt="[Solid logo]" /></a>
-    <h1>Community Solid Server</h1>
-  </header>
-  <main>
-    <h1>Email sent</h1>
-    <form action="/idp/forgotpassword" method="post">
-      <p>If your account exists, an email has been sent with a link to reset your password.</p>
-      <p>If you do not receive your email in a couple of minutes, check your spam folder or click the link below to send another email.</p>
-
-      <input type="hidden" name="email" value="<%= email %>" />
-
-      <p class="actions"><a href="/idp/login">Back to Log In</a></p>
-
-      <hr />
-      <p class="actions">
-        <button type="submit" name="submit" class="link">Send Another Email</button>
-      </p>
-    </form>
-  </main>
-  <footer>
-    <p>
-      ©2019–2021 <a href="https://inrupt.com/">Inrupt Inc.</a>
-      and <a href="https://www.imec-int.com/">imec</a>
-    </p>
-  </footer>
-</body>
-</html>

templates/identity/email-password/forgot-password-response.html.ejs

@@ -0,0 +1,13 @@
+<h1>Email sent</h1>
+<form action="/idp/forgotpassword" method="post">
+  <p>If your account exists, an email has been sent with a link to reset your password.</p>
+  <p>If you do not receive your email in a couple of minutes, check your spam folder or click the link below to send another email.</p>
+
+  <input type="hidden" name="email" value="<%= email %>" />
+
+  <p class="actions"><a href="/idp/login">Back to Log In</a></p>
+
+  <p class="actions">
+    <button type="submit" name="submit" class="link">Send Another Email</button>
+  </p>
+</form>

templates/identity/email-password/forgot-password.html.ejs

@@ -1,19 +1,5 @@
-<!DOCTYPE html>
+<h1>Forgot password</h1>
-<html lang="en">
+<form action="/idp/forgotpassword" method="post">
-<head>
-  <meta charset="utf-8"/>
-  <meta name="viewport" content="width=device-width, initial-scale=1"/>
-  <title>Forgot password</title>
-  <link rel="stylesheet" href="/.well_known/css/styles/main.css" type="text/css">
-</head>
-<body>
-  <header>
-    <a href="/"><img src="/.well_known/css/images/solid.svg" alt="[Solid logo]" /></a>
-    <h1>Community Solid Server</h1>
-  </header>
-  <main>
-    <h1>Forgot password</h1>
-    <form action="/idp/forgotpassword" method="post">
   <%if (errorMessage) { %>
     <p class="error"><%= errorMessage %></p>
   <% } %>
@@ -30,13 +16,4 @@
   <p class="actions"><button type="submit" name="submit">Send recovery email</button></p>
 
   <p class="actions"><a href="/idp/login" class="link">Log in</a></p>
-    </form>
+</form>
-  </main>
-  <footer>
-    <p>
-      ©2019–2021 <a href="https://inrupt.com/">Inrupt Inc.</a>
-      and <a href="https://www.imec-int.com/">imec</a>
-    </p>
-  </footer>
-</body>
-</html>

templates/identity/email-password/login.html.ejs

@@ -1,19 +1,5 @@
-<!DOCTYPE html>
+<h1>Log in</h1>
-<html lang="en">
+<form action="/idp/login" method="post">
-<head>
-  <meta charset="utf-8"/>
-  <meta name="viewport" content="width=device-width, initial-scale=1"/>
-  <title>Log in</title>
-  <link rel="stylesheet" href="/.well_known/css/styles/main.css" type="text/css">
-</head>
-<body>
-  <header>
-    <a href="/"><img src="/.well_known/css/images/solid.svg" alt="[Solid logo]" /></a>
-    <h1>Community Solid Server</h1>
-  </header>
-  <main>
-    <h1>Log in</h1>
-    <form action="/idp/login" method="post">
   <%if (errorMessage) { %>
     <p class="error"><%= errorMessage %></p>
   <% } %>
@@ -41,13 +27,4 @@
     <li><a href="/idp/register" class="link">Sign up</a></li>
     <li><a href="/idp/forgotpassword" class="link">Forgot password</a></li>
   </ul>
-    </form>
+</form>
-  </main>
-  <footer>
-    <p>
-      ©2019–2021 <a href="https://inrupt.com/">Inrupt Inc.</a>
-      and <a href="https://www.imec-int.com/">imec</a>
-    </p>
-  </footer>
-</body>
-</html>

templates/identity/email-password/register-response.html.ejs

@@ -1,42 +1,28 @@
-<!DOCTYPE html>
+<h1>You've been signed up</h1>
-<html lang="en">
+<p>
-<head>
-  <meta charset="utf-8"/>
-  <meta name="viewport" content="width=device-width, initial-scale=1"/>
-  <title>You are signed up</title>
-  <link rel="stylesheet" href="/.well_known/css/styles/main.css" type="text/css">
-</head>
-<body>
-  <header>
-    <a href="/"><img src="/.well_known/css/images/solid.svg" alt="[Solid logo]" /></a>
-    <h1>Community Solid Server</h1>
-  </header>
-  <main>
-    <h1>You are signed up</h1>
-    <p>
   <strong>Welcome to Solid.</strong>
   We wish you an exciting experience!
-    </p>
+</p>
 
-    <% if (createPod) { %>
+<% if (createPod) { %>
   <h2>Your new Pod</h2>
   <p>
     Your new Pod is located at <a href="<%= podBaseUrl %>" class="link"><%= podBaseUrl %></a>.
     <br>
     You can store your documents and data there.
   </p>
-    <% } %>
+<% } %>
 
-    <% if (createWebId) { %>
+<% if (createWebId) { %>
   <h2>Your new WebID</h2>
   <p>
     Your new WebID is <a href="<%= webId %>" class="link"><%= webId %></a>.
     <br>
     You can use this identifier to interact with Solid pods and apps.
   </p>
-    <% } %>
+<% } %>
 
-    <% if (register) { %>
+<% if (register) { %>
   <h2>Your new account</h2>
   <p>
     Via your email address <em><%= email %></em>,
@@ -51,13 +37,4 @@
       to indicate that you trust this server as a login provider.
     </p>
   <% } %>
-    <% } %>
+<% } %>
-  </main>
-  <footer>
-    <p>
-      ©2019–2021 <a href="https://inrupt.com/">Inrupt Inc.</a>
-      and <a href="https://www.imec-int.com/">imec</a>
-    </p>
-  </footer>
-</body>
-</html>

templates/identity/email-password/register.html.ejs

@@ -1,19 +1,5 @@
-<!DOCTYPE html>
+<h1>Sign up</h1>
-<html lang="en">
+<form action="/idp/register" method="post" id="mainForm">
-<head>
-  <meta charset="utf-8"/>
-  <meta name="viewport" content="width=device-width, initial-scale=1"/>
-  <title>Register</title>
-  <link rel="stylesheet" href="/.well_known/css/styles/main.css" type="text/css">
-</head>
-<body>
-  <header>
-    <a href="/"><img src="/.well_known/css/images/solid.svg" alt="[Solid logo]" /></a>
-    <h1>Community Solid Server</h1>
-  </header>
-  <main>
-    <h1>Sign up</h1>
-    <form action="/idp/register" method="post" id="mainForm">
   <% const isBlankForm = !('email' in prefilled); %>
 
   <% if (errorMessage) { %>
@@ -122,11 +108,11 @@
   </fieldset>
 
   <p class="actions"><button type="submit" name="submit">Sign up</button></p>
-    </form>
+</form>
 
-    <script>
+<script>
-    // Assist the user with filling out the form by hiding irrelevant fields
+// Assist the user with filling out the form by hiding irrelevant fields
-    (() => {
+(() => {
   // Wire up the UI elements
   const elements = {};
   [
@@ -199,14 +185,5 @@
       child.disabled = false;
   });
   elements.mainForm.addEventListener('formdata', updateUI);
-    })();
+})();
-    </script>
+</script>
-  </main>
-  <footer>
-    <p>
-      ©2019–2021 <a href="https://inrupt.com/">Inrupt Inc.</a>
-      and <a href="https://www.imec-int.com/">imec</a>
-    </p>
-  </footer>
-</body>
-</html>

templates/identity/email-password/reset-password-response.html.ejs

@@ -0,0 +1,2 @@
+<h1>Password reset</h1>
+<p>Your password was successfully reset.</p>

templates/identity/email-password/reset-password.html.ejs

@@ -1,19 +1,5 @@
-<!DOCTYPE html>
+<h1>Reset password</h1>
-<html lang="en">
+<form method="post">
-<head>
-  <meta charset="utf-8"/>
-  <meta name="viewport" content="width=device-width, initial-scale=1"/>
-  <title>Reset password</title>
-  <link rel="stylesheet" href="/.well_known/css/styles/main.css" type="text/css">
-</head>
-<body>
-  <header>
-    <a href="/"><img src="/.well_known/css/images/solid.svg" alt="[Solid logo]" /></a>
-    <h1>Community Solid Server</h1>
-  </header>
-  <main>
-    <h1>Reset password</h1>
-    <form method="post">
   <%if (errorMessage) { %>
     <p class="error"><%= errorMessage %></p>
   <% } %>
@@ -32,13 +18,4 @@
   </fieldset>
 
   <p class="actions"><button type="submit" name="submit">Reset password</button></p>
-    </form>
+</form>
-  </main>
-  <footer>
-    <p>
-      ©2019–2021 <a href="https://inrupt.com/">Inrupt Inc.</a>
-      and <a href="https://www.imec-int.com/">imec</a>
-    </p>
-  </footer>
-</body>
-</html>

templates/main.html.ejs

@@ -3,7 +3,7 @@
 <head>
   <meta charset="utf-8"/>
   <meta name="viewport" content="width=device-width, initial-scale=1"/>
-  <title><%= message %></title>
+  <title><%= extractTitle(htmlBody) %></title>
   <link rel="stylesheet" href="/.well_known/css/styles/main.css" type="text/css">
 </head>
 <body>
@@ -12,7 +12,7 @@
     <h1>Community Solid Server</h1>
   </header>
   <main>
-    <p><%= message %></p>
+    <%- htmlBody %>
   </main>
   <footer>
     <p>
@@ -22,3 +22,10 @@
   </footer>
 </body>
 </html>
+
+<%
+function extractTitle(body) {
+  const match = /^<h1[^>]*>([^<]*)<\/h1>/u.exec(body);
+  return match ? match[1] : 'Solid';
+}
+%>

templates/main.html.hbs

@@ -1,26 +0,0 @@
-<!DOCTYPE html>
-<html lang="en">
-<head>
-  <meta charset="utf-8"/>
-  <meta name="viewport" content="width=device-width, initial-scale=1"/>
-  {{#if title}}
-  <title>{{ title }}</title>
-  {{/if}}
-  <link rel="stylesheet" href="/.well_known/css/styles/main.css" type="text/css">
-</head>
-<body>
-  <header>
-    <a href="/"><img src="/.well_known/css/images/solid.svg" alt="[Solid logo]" /></a>
-    <h1>Community Solid Server</h1>
-  </header>
-  <main>
-    {{{ htmlBody }}}
-  </main>
-  <footer>
-    <p>
-      ©2019–2021 <a href="https://inrupt.com/">Inrupt Inc.</a>
-      and <a href="https://www.imec-int.com/">imec</a>
-    </p>
-  </footer>
-</body>
-</html>

test/unit/identity/IdentityProviderHttpHandler.test.ts

@@ -100,6 +100,19 @@ describe('An IdentityProviderHttpHandler', (): void => {
     );
   });
 
+  it('supports InteractionResponseResults without details.', async(): Promise<void> => {
+    request.url = '/idp/routeResponse';
+    request.method = 'POST';
+    (routes.response.handler as jest.Mocked<InteractionHandler>).handleSafe.mockResolvedValueOnce({ type: 'response' });
+    await expect(handler.handle({ request, response })).resolves.toBeUndefined();
+    expect(routes.response.handler.handleSafe).toHaveBeenCalledTimes(1);
+    expect(routes.response.handler.handleSafe).toHaveBeenLastCalledWith({ request, response });
+    expect(templateHandler.handleSafe).toHaveBeenCalledTimes(1);
+    expect(templateHandler.handleSafe).toHaveBeenLastCalledWith(
+      { response, templateFile: routes.response.responseTemplate, contents: {}},
+    );
+  });
+
   it('calls the interactionCompleter for InteractionCompleteResults.', async(): Promise<void> => {
     request.url = '/idp/routeComplete';
     request.method = 'POST';

test/unit/identity/interaction/email-password/handler/ResetPasswordHandler.test.ts

@@ -48,10 +48,7 @@ describe('A ResetPasswordHandler', (): void => {
 
   it('renders a message on success.', async(): Promise<void> => {
     request = createPostFormRequest({ password: 'password!', confirmPassword: 'password!' }, url);
-    await expect(handler.handle({ request, response })).resolves.toEqual({
+    await expect(handler.handle({ request, response })).resolves.toEqual({ type: 'response' });
-      details: { message: 'Your password was successfully reset.' },
-      type: 'response',
-    });
     expect(accountStore.getForgotPasswordRecord).toHaveBeenCalledTimes(1);
     expect(accountStore.getForgotPasswordRecord).toHaveBeenLastCalledWith(recordId);
     expect(accountStore.deleteForgotPasswordRecord).toHaveBeenCalledTimes(1);

test/unit/storage/conversion/MarkdownToHtmlConverter.test.ts

@@ -35,19 +35,4 @@ describe('A MarkdownToHtmlConverter', (): void => {
       { htmlBody: '<p>Text <code>code</code> more text.</p>\n' },
     );
   });
-
-  it('uses the main markdown header as title if there is one.', async(): Promise<void> => {
-    const markdown = '# title text\nmore text';
-    const representation = new BasicRepresentation(markdown, 'text/markdown', true);
-    const prom = converter.handle({ identifier, representation, preferences });
-    await expect(prom).resolves.toBeDefined();
-    const result = await prom;
-    expect(result.binary).toBe(true);
-    expect(result.metadata.contentType).toBe('text/html');
-    await expect(readableToString(result.data)).resolves.toBe('<html>');
-    expect(templateEngine.render).toHaveBeenCalledTimes(1);
-    expect(templateEngine.render).toHaveBeenLastCalledWith(
-      { htmlBody: '<h1 id="title-text">title text</h1>\n<p>more text</p>\n', title: 'title text' },
-    );
-  });
 });

test/unit/util/templates/ChainedTemplateEngine.test.ts

@@ -0,0 +1,39 @@
+import { ChainedTemplateEngine } from '../../../../src/util/templates/ChainedTemplateEngine';
+import type { TemplateEngine } from '../../../../src/util/templates/TemplateEngine';
+
+describe('A ChainedTemplateEngine', (): void => {
+  const contents = { title: 'myTitle' };
+  const template = { templateFile: '/template.tmpl' };
+  let engines: jest.Mocked<TemplateEngine>[];
+  let engine: ChainedTemplateEngine;
+
+  beforeEach(async(): Promise<void> => {
+    engines = [
+      { render: jest.fn().mockResolvedValue('body1') },
+      { render: jest.fn().mockResolvedValue('body2') },
+    ];
+
+    engine = new ChainedTemplateEngine(engines);
+  });
+
+  it('errors if no engines are provided.', async(): Promise<void> => {
+    expect((): any => new ChainedTemplateEngine([])).toThrow('At least 1 engine needs to be provided.');
+  });
+
+  it('chains the engines.', async(): Promise<void> => {
+    await expect(engine.render(contents, template)).resolves.toEqual('body2');
+    expect(engines[0].render).toHaveBeenCalledTimes(1);
+    expect(engines[0].render).toHaveBeenLastCalledWith(contents, template);
+    expect(engines[1].render).toHaveBeenCalledTimes(1);
+    expect(engines[1].render).toHaveBeenLastCalledWith({ ...contents, body: 'body1' });
+  });
+
+  it('can use a different field to pass along the body.', async(): Promise<void> => {
+    engine = new ChainedTemplateEngine(engines, 'different');
+    await expect(engine.render(contents, template)).resolves.toEqual('body2');
+    expect(engines[0].render).toHaveBeenCalledTimes(1);
+    expect(engines[0].render).toHaveBeenLastCalledWith(contents, template);
+    expect(engines[1].render).toHaveBeenCalledTimes(1);
+    expect(engines[1].render).toHaveBeenLastCalledWith({ ...contents, different: 'body1' });
+  });
+});