feat(html): enable setting of HTTP headers through link and meta HTML…

… tags fixes #122
adobe · Apr 29, 2019 · 32e4494 · 32e4494
1 parent 59665f7
commit 32e4494
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Showing 5 changed files with 149 additions and 0 deletions.
diff --git a/package-lock.json b/package-lock.json
diff --git a/package.json b/package.json
@@ -56,6 +56,7 @@
     "fs-extra": "^7.0.0",
     "github-slugger": "^1.2.1",
     "hast-to-hyperscript": "^7.0.0",
+    "hast-util-select": "^3.0.0",
     "hast-util-to-html": "^5.0.0",
     "hyperscript": "^2.0.2",
     "js-yaml": "^3.13.1",

diff --git a/src/defaults/html.pipe.js b/src/defaults/html.pipe.js
@@ -34,6 +34,7 @@ const parseFrontmatter = require('../html/parse-frontmatter');
 const rewriteLinks = require('../html/static-asset-links');
 const tohast = require('../html/html-to-hast');
 const tohtml = require('../html/stringify-hast');
+const addHeaders = require('../html/add-headers');
 
 /* eslint no-param-reassign: off */
 /* eslint newline-per-chained-call: off */
@@ -67,6 +68,7 @@ const htmlpipe = (cont, payload, action) => {
     .after(debug)
     .after(tohast) // start HTML post-processing
     .after(rewriteLinks).when(production)
+    .after(addHeaders)
     .after(tohtml) // end HTML post-processing
     .after(flag).expose('esi').when(esi) // flag ESI when there is ESI in the response
     .error(selectStatus(production()));

diff --git a/src/html/add-headers.js b/src/html/add-headers.js
@@ -0,0 +1,42 @@
+/*
+ * Copyright 2019 Adobe. All rights reserved.
+ * This file is licensed to you under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License. You may obtain a copy
+ * of the License at http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under
+ * the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
+ * OF ANY KIND, either express or implied. See the License for the specific language
+ * governing permissions and limitations under the License.
+ */
+
+const { selectAll } = require('hast-util-select');
+
+function addHeaders({ response: { headers, hast } }) {
+  const linkheaders = selectAll('link[rel][href]', hast).reduce((h, { properties: { href, rel } }) => {
+    if (!href.match(/<esi:include/)) {
+      // eslint-disable-next-line no-param-reassign
+      h.Link = `${h.Link ? `${h.Link},` : ''
+      }<${href}>; rel="${rel}"`;
+    }
+    return h;
+  }, headers);
+
+  const metaheaders = selectAll('meta[http-equiv][content]', hast).reduce((h, { properties: { httpEquiv, content } }) => {
+    const name = httpEquiv;
+    const value = content;
+    if (!h[name]) {
+      // eslint-disable-next-line no-param-reassign
+      h[name] = value;
+    }
+    return h;
+  }, linkheaders);
+
+  return {
+    response: {
+      headers: metaheaders,
+    },
+  };
+}
+
+module.exports = addHeaders;
diff --git a/test/testHTML.js b/test/testHTML.js
@@ -117,6 +117,69 @@ const crequest = {
   url: '/test/test.html',
 };
 
+describe('Testing HTML Pipeline in Production', () => {
+  let production;
+  before('Fake Production Mode', () => {
+    // eslint-disable-next-line no-underscore-dangle
+    production = process.env.__OW_ACTIVATION_ID;
+    // eslint-disable-next-line no-underscore-dangle
+    process.env.__OW_ACTIVATION_ID = 'fake';
+  });
+
+
+  it('html.pipe adds headers from meta and link tags', async () => {
+    const result = await pipe(
+      ({ content }) => ({
+        response: {
+          status: 201,
+          headers: {
+            Foo: 'bar',
+          },
+          body: `<html>
+  <head>
+    <title>Hello World</title>
+    <meta http-equiv="Expires" content="3000">
+    <meta http-equiv="Foo" content="baz">
+    <meta http-equiv="Exceeds" value="3000">
+    <link rel="next" href="next.html" />
+    <link rel="stylesheet" href="style.css" />
+    <link rel="first" href="index.html" />
+    <link rel="previous" src="previous.html" />
+  </head>
+  <body>
+    ${content.document.body.innerHTML}
+  </body>
+</html>`,
+        },
+      }),
+      {
+        request: crequest,
+        content: {
+          body: 'Hello World',
+        },
+      },
+      {
+        request: { params },
+        secrets,
+        logger,
+      },
+    );
+
+    assert.equal(result.response.status, 201);
+    assert.equal(result.response.headers['Content-Type'], 'text/html', 'keeps content-type');
+    assert.equal(result.response.headers['X-ESI'], 'enabled', 'detects ESI');
+    assert.equal(result.response.headers.Expires, '3000', 'allows setting through meta http-equiv');
+    assert.equal(result.response.headers.Exceeds, undefined, 'ignores invalid meta tags');
+    assert.equal(result.response.headers.Foo, 'bar', 'does not override existing headers');
+    assert.equal(result.response.headers.Link, '<next.html>; rel="next",<index.html>; rel="first"', 'allows setting through link');
+  });
+
+  after('Reset Production Mode', () => {
+    // eslint-disable-next-line no-underscore-dangle
+    process.env.__OW_ACTIVATION_ID = production;
+  });
+});
+
 describe('Testing HTML Pipeline', () => {
   setupPolly({
     logging: false,