From b5873e523122d1625188aa852c55b35335db218a Mon Sep 17 00:00:00 2001
From: Peter Bengtsson <mail@peterbe.com>
Date: Thu, 29 Oct 2020 09:51:16 -0400
Subject: [PATCH 1/9] Use git log know a documents last modified date

Fixes #706
---
 .github/workflows/production-build.yml |  5 ++++
 build/git-history.js                   | 33 ++++++++++++++++++++++++++
 build/index.js                         |  2 ++
 package.json                           |  2 +-
 tool/cli.js                            | 15 ++++++++++++
 5 files changed, 56 insertions(+), 1 deletion(-)
 create mode 100644 build/git-history.js

diff --git a/.github/workflows/production-build.yml b/.github/workflows/production-build.yml
index c8892b227d21..49927bd631fb 100644
--- a/.github/workflows/production-build.yml
+++ b/.github/workflows/production-build.yml
@@ -47,6 +47,11 @@ jobs:
         with:
           repository: mdn/content
           path: mdn/content
+          # Yes, this means fetch EVERY COMMIT EVER.
+          # It's probably not sustainable in the far future (e.g. past 2021)
+          # but for now it's good enough. We'll need all the history
+          # so we can figure out each document's last-modified date.
+          fetch-depth: 0
 
       - uses: actions/checkout@v2
         if: "contains(github.event.inputs.archived_content, 'true')"
diff --git a/build/git-history.js b/build/git-history.js
new file mode 100644
index 000000000000..4c30290cb593
--- /dev/null
+++ b/build/git-history.js
@@ -0,0 +1,33 @@
+const childProcess = require("child_process");
+const fs = require("fs");
+const path = require("path");
+
+const { execGit } = require("../content");
+
+function getFromGit() {
+  const output = execGit([
+    "log",
+    "--name-only",
+    "--no-decorate",
+    '--format="←→ %ci"',
+    "--date-order",
+    "--reverse",
+  ]);
+  const map = new Map();
+  output
+    .split("←→")
+    .slice(1)
+    .forEach((commit) => {
+      const [date, , ...files] = commit.trim().split("\n");
+      const iso = new Date(date).toISOString();
+      for (const file of files) {
+        map.set(file, iso);
+      }
+    });
+  return map;
+}
+function gather(outputfile, previousfile = null) {}
+
+module.exports = {
+  gather,
+};
diff --git a/build/index.js b/build/index.js
index 5940df5660dc..147013bd13b8 100644
--- a/build/index.js
+++ b/build/index.js
@@ -23,6 +23,7 @@ const { getPageTitle } = require("./page-title");
 const { syntaxHighlight } = require("./syntax-highlight");
 const cheerio = require("./monkeypatched-cheerio");
 const buildOptions = require("./build-options");
+const { gather: gatherGitHistory } = require("./git-history");
 const { renderCache: renderKumascriptCache } = require("../kumascript");
 
 const DEFAULT_BRANCH_NAME = "main"; // That's what we use for github.com/mdn/content
@@ -380,4 +381,5 @@ module.exports = {
   SearchIndex,
 
   options: buildOptions,
+  gatherGitHistory,
 };
diff --git a/package.json b/package.json
index c785bc4ce2d9..59483cb25dc6 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,7 @@
     "test": "yarn prettier-check && yarn test:client && yarn test:kumascript && yarn test:testing",
     "build:client": "cd client && cross-env INLINE_RUNTIME_CHUNK=false react-scripts build",
     "build:ssr": "cd ssr && webpack --config webpack.config.js --mode=production",
-    "prepare-build": "yarn build:client && yarn build:ssr",
+    "prepare-build": "yarn build:client && yarn build:ssr && yarn tool gather-git-history",
     "build": "cd build && cross-env NODE_ENV=production node cli.js",
     "start": "(test -f client/build/index.html || yarn build:client) && (test -f ssr/dist/main.js || yarn build:ssr) && nf -j Procfile.start start",
     "dev": "yarn build:client && yarn build:ssr && nf -j Procfile.dev start",
diff --git a/tool/cli.js b/tool/cli.js
index b94257edfa4c..84f0cb781887 100644
--- a/tool/cli.js
+++ b/tool/cli.js
@@ -9,6 +9,7 @@ const path = require("path");
 
 const { DEFAULT_LOCALE, VALID_LOCALES } = require("../libs/constants");
 const { Redirect, Document, buildURL } = require("../content");
+const { gatherGitHistory } = require("../build");
 
 const PORT = parseInt(process.env.SERVER_PORT || "5000");
 
@@ -219,6 +220,20 @@ program
       const url = `http://localhost:${PORT}${buildURL(locale, slug)}`;
       await open(url);
     })
+  )
+
+  .command(
+    "gather-git-history",
+    "Extract all last-modified dates from the git logs"
+  )
+  .argument("<outputfile>", "Where to dump the JSON file with all the data")
+  .argument("[previousfile]", "Optional old file to extend")
+  .action(
+    tryOrExit(async ({ args }) => {
+      const { outputfile, previousfile } = args;
+      const data = gatherGitHistory(outputfile, previousfile);
+      console.log(chalk.green(data));
+    })
   );
 
 program.run();

From f2e110c35600985e4df6dd2590458c2e12d3761e Mon Sep 17 00:00:00 2001
From: Peter Bengtsson <mail@peterbe.com>
Date: Thu, 29 Oct 2020 12:08:08 -0400
Subject: [PATCH 2/9] progress

---
 build/git-history.js | 62 +++++++++++++++++++++++++++++---------------
 1 file changed, 41 insertions(+), 21 deletions(-)

diff --git a/build/git-history.js b/build/git-history.js
index 4c30290cb593..8c8d606c546f 100644
--- a/build/git-history.js
+++ b/build/git-history.js
@@ -1,32 +1,52 @@
-const childProcess = require("child_process");
 const fs = require("fs");
 const path = require("path");
 
-const { execGit } = require("../content");
+const { CONTENT_ROOT, execGit } = require("../content");
 
 function getFromGit() {
-  const output = execGit([
-    "log",
-    "--name-only",
-    "--no-decorate",
-    '--format="←→ %ci"',
-    "--date-order",
-    "--reverse",
-  ]);
+  const repoRoot = execGit(["rev-parse", "--show-toplevel"], {
+    cwd: CONTENT_ROOT,
+  });
+
+  const MARKER = "COMMIT:";
+  const output = execGit(
+    [
+      "log",
+      "--name-only",
+      "--no-decorate",
+      `--format=${MARKER}%cI`,
+      "--date-order",
+      "--reverse",
+    ],
+    {
+      cwd: repoRoot,
+    }
+  );
+
   const map = new Map();
-  output
-    .split("←→")
-    .slice(1)
-    .forEach((commit) => {
-      const [date, , ...files] = commit.trim().split("\n");
-      const iso = new Date(date).toISOString();
-      for (const file of files) {
-        map.set(file, iso);
-      }
-    });
+  let date = null;
+  for (let line of output.split("\n")) {
+    // Happens to file paths that contain non-ascii or control charaters.
+    // E.g. "files/en-us/glossary/b\303\251zier_curve/index.html"
+    if (line.startsWith('"') && line.endsWith('"')) {
+      line = line.slice(1, -1);
+    }
+    if (line.startsWith(MARKER)) {
+      date = new Date(line.replace(MARKER, ""));
+    } else if (line) {
+      map.set(line, date);
+    }
+  }
   return map;
 }
-function gather(outputfile, previousfile = null) {}
+function gather(outputfile, previousfile = null) {
+  // Every key in this map
+  const map = getFromGit();
+  for (const [key, date] of map) {
+    if (!key.includes("files/en-us/")) console.log({ key, date });
+    // console.log({ key, date });
+  }
+}
 
 module.exports = {
   gather,

From 0d24109bf275f2e28a42bc1410a51f6c066fccf0 Mon Sep 17 00:00:00 2001
From: Peter Bengtsson <mail@peterbe.com>
Date: Thu, 29 Oct 2020 17:37:16 -0400
Subject: [PATCH 3/9] Use git log know a documents last modified date

Part of #706
---
 build/git-history.js    | 36 +++++++++++++++-----
 content/document.js     | 11 ++++++-
 content/githistories.js | 26 +++++++++++++++
 tool/cli.js             | 73 ++++++++++++++++++++++++++++++++++++-----
 4 files changed, 127 insertions(+), 19 deletions(-)
 create mode 100644 content/githistories.js

diff --git a/build/git-history.js b/build/git-history.js
index 8c8d606c546f..b8687e2c1e44 100644
--- a/build/git-history.js
+++ b/build/git-history.js
@@ -3,9 +3,9 @@ const path = require("path");
 
 const { CONTENT_ROOT, execGit } = require("../content");
 
-function getFromGit() {
+function getFromGit(contentRoot = CONTENT_ROOT) {
   const repoRoot = execGit(["rev-parse", "--show-toplevel"], {
-    cwd: CONTENT_ROOT,
+    cwd: contentRoot,
   });
 
   const MARKER = "COMMIT:";
@@ -34,18 +34,36 @@ function getFromGit() {
     if (line.startsWith(MARKER)) {
       date = new Date(line.replace(MARKER, ""));
     } else if (line) {
-      map.set(line, date);
+      const relPath = path.relative(contentRoot, path.join(repoRoot, line));
+      map.set(relPath, date);
     }
   }
   return map;
 }
-function gather(outputfile, previousfile = null) {
-  // Every key in this map
-  const map = getFromGit();
-  for (const [key, date] of map) {
-    if (!key.includes("files/en-us/")) console.log({ key, date });
-    // console.log({ key, date });
+function gather(contentRoot, previousFile = null) {
+  const map = new Map();
+  if (previousFile) {
+    const previous = JSON.parse(fs.readFileSync(previousFile, "utf-8"));
+    for (const [key, value] of Object.entries(previous)) {
+      map.set(key, value);
+    }
   }
+  // Every key in this map is a path, relative to CONTENT_ROOT.
+  for (const [key, value] of getFromGit(contentRoot)) {
+    // Because CONTENT_ROOT isn't necessarily the same as the path relative to
+    // the git root. For example "../README.md" and since those aren't documents
+    // exclude them.
+    // We also only care about documents.
+    if (
+      !key.startsWith(".") &&
+      (key.endsWith("index.html") || key.endsWith("index.md"))
+    ) {
+      map.set(key, {
+        modified: value,
+      });
+    }
+  }
+  return map;
 }
 
 module.exports = {
diff --git a/content/document.js b/content/document.js
index bea86ac22437..404b2d010d07 100644
--- a/content/document.js
+++ b/content/document.js
@@ -14,6 +14,7 @@ const {
 } = require("./constants");
 const { getPopularities } = require("./popularities");
 const { getWikiHistories } = require("./wikihistories");
+const { getGitHistories } = require("./githistories");
 
 const { buildURL, memoize, slugToFolder, execGit } = require("./utils");
 const Redirect = require("./redirect");
@@ -169,13 +170,21 @@ const read = memoize((folder) => {
 
   const locale = extractLocale(folder);
   const url = `/${locale}/docs/${metadata.slug}`;
+
+  // The last-modified is always coming from the git logs. Independent of
+  // which root it is.
+  const gitHistory = getGitHistories(root, locale).get(
+    path.relative(root, filePath)
+  );
+  const modified = (gitHistory && gitHistory.modified) || null;
+  // Use the wiki histories for a list of legacy contributors.
   const wikiHistory = getWikiHistories(root, locale).get(url);
   const fullMetadata = {
     metadata: {
       ...metadata,
       locale,
       popularity: getPopularities().get(url) || 0.0,
-      modified: wikiHistory ? wikiHistory.modified : null,
+      modified,
       contributors: wikiHistory ? wikiHistory.contributors : [],
     },
     url,
diff --git a/content/githistories.js b/content/githistories.js
new file mode 100644
index 000000000000..f12a494edb94
--- /dev/null
+++ b/content/githistories.js
@@ -0,0 +1,26 @@
+const fs = require("fs");
+const path = require("path");
+
+// Module-level cache
+const gitHistoryMaps = new Map();
+
+function getGitHistories(root, locale) {
+  const localeLC = locale.toLowerCase();
+  const folder = path.join(root, localeLC);
+  if (!gitHistoryMaps.has(folder)) {
+    const historyFilePath = path.join(folder, "_githistory.json");
+    const history = fs.existsSync(historyFilePath)
+      ? new Map(
+          Object.entries(JSON.parse(fs.readFileSync(historyFilePath))).map(
+            ([filePath, history]) => {
+              return [filePath, history];
+            }
+          )
+        )
+      : new Map();
+    gitHistoryMaps.set(folder, history);
+  }
+  return gitHistoryMaps.get(folder);
+}
+
+module.exports = { getGitHistories };
diff --git a/tool/cli.js b/tool/cli.js
index 84f0cb781887..8b2f148ff06c 100644
--- a/tool/cli.js
+++ b/tool/cli.js
@@ -1,14 +1,16 @@
 #!/usr/bin/env node
+const fs = require("fs");
+const path = require("path");
+const os = require("os");
+
 const program = require("@caporal/core").default;
 const chalk = require("chalk");
 const prompts = require("prompts");
 const openEditor = require("open-editor");
 const open = require("open");
-const fs = require("fs");
-const path = require("path");
 
 const { DEFAULT_LOCALE, VALID_LOCALES } = require("../libs/constants");
-const { Redirect, Document, buildURL } = require("../content");
+const { CONTENT_ROOT, Redirect, Document, buildURL } = require("../content");
 const { gatherGitHistory } = require("../build");
 
 const PORT = parseInt(process.env.SERVER_PORT || "5000");
@@ -226,13 +228,66 @@ program
     "gather-git-history",
     "Extract all last-modified dates from the git logs"
   )
-  .argument("<outputfile>", "Where to dump the JSON file with all the data")
-  .argument("[previousfile]", "Optional old file to extend")
+  .option("--root <directory>", "Which content root", {
+    default: CONTENT_ROOT,
+  })
+  .option("--save-history <path>", `File to save all previous history`, {
+    default: path.join(os.tmpdir(), "yari-git-history.json"),
+  })
+  .option(
+    "--load-history <path>",
+    `Optional file to load all previous history`,
+    {
+      default: path.join(os.tmpdir(), "yari-git-history.json"),
+    }
+  )
   .action(
-    tryOrExit(async ({ args }) => {
-      const { outputfile, previousfile } = args;
-      const data = gatherGitHistory(outputfile, previousfile);
-      console.log(chalk.green(data));
+    tryOrExit(async ({ options }) => {
+      const { root, saveHistory, loadHistory } = options;
+      if (fs.existsSync(loadHistory)) {
+        console.log(
+          chalk.yellow(`Reusing exising history from ${loadHistory}`)
+        );
+      }
+      const map = gatherGitHistory(
+        root,
+        fs.existsSync(loadHistory) ? loadHistory : null
+      );
+      const historyPerLocale = {};
+
+      // Someplace to put the map into an object so it can be saved into `saveHistory`
+      const allHistory = {};
+      for (const [relPath, value] of map) {
+        allHistory[relPath] = value;
+        const locale = relPath.split("/")[0];
+        if (!historyPerLocale[locale]) {
+          historyPerLocale[locale] = {};
+        }
+        historyPerLocale[locale][relPath] = value;
+      }
+      for (const [locale, history] of Object.entries(historyPerLocale)) {
+        const outputFile = path.join(root, locale, "_githistory.json");
+        fs.writeFileSync(outputFile, JSON.stringify(history, null, 2), "utf-8");
+        console.log(
+          chalk.green(
+            `Wrote '${locale}' ${Object.keys(
+              history
+            ).length.toLocaleString()} paths into ${outputFile}`
+          )
+        );
+      }
+      fs.writeFileSync(
+        saveHistory,
+        JSON.stringify(allHistory, null, 2),
+        "utf-8"
+      );
+      console.log(
+        chalk.green(
+          `Wrote ${Object.keys(
+            allHistory
+          ).length.toLocaleString()} paths into ${saveHistory}`
+        )
+      );
     })
   );
 

From 4e621f2c6acf9a84e548505e7eb3cc694caae826 Mon Sep 17 00:00:00 2001
From: Peter Bengtsson <mail@peterbe.com>
Date: Mon, 9 Nov 2020 16:48:31 -0500
Subject: [PATCH 4/9] wording

---
 tool/cli.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tool/cli.js b/tool/cli.js
index a91d2daf9740..5818ced9851c 100644
--- a/tool/cli.js
+++ b/tool/cli.js
@@ -302,7 +302,7 @@ program
       );
       console.log(
         chalk.green(
-          `Wrote ${Object.keys(
+          `Saved ${Object.keys(
             allHistory
           ).length.toLocaleString()} paths into ${saveHistory}`
         )

From e4fadd7e40145f101b0a9d26a950521941a6c318 Mon Sep 17 00:00:00 2001
From: Peter Bengtsson <mail@peterbe.com>
Date: Mon, 9 Nov 2020 18:41:49 -0500
Subject: [PATCH 5/9] getting tests to work

---
 .gitignore           | 2 ++
 build/git-history.js | 3 ++-
 content/utils.js     | 9 ++++++++-
 package.json         | 4 ++--
 testing/.env         | 4 ++--
 5 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/.gitignore b/.gitignore
index c84f3ea7e4ac..b612dd1fed59 100644
--- a/.gitignore
+++ b/.gitignore
@@ -70,3 +70,5 @@ yarn-error.log*
 fake-v1-api/
 mdn-yari-*.tgz
 function.zip
+
+testing/content/files/en-us/_githistory.json
diff --git a/build/git-history.js b/build/git-history.js
index b8687e2c1e44..152b5e705a8f 100644
--- a/build/git-history.js
+++ b/build/git-history.js
@@ -20,7 +20,8 @@ function getFromGit(contentRoot = CONTENT_ROOT) {
     ],
     {
       cwd: repoRoot,
-    }
+    },
+    repoRoot
   );
 
   const map = new Map();
diff --git a/content/utils.js b/content/utils.js
index 1767228f652a..9b6925381791 100644
--- a/content/utils.js
+++ b/content/utils.js
@@ -84,10 +84,17 @@ function execGit(args, opts = {}, root = null) {
     args,
     {
       cwd: gitRoot,
+      maxBuffer: 1024 * 1024 * 100, // 100MB
     }
   );
   if (error || status !== 0) {
-    throw new Error(`git command failed:\n${stderr.toString()}`);
+    if (stderr) {
+      console.error(stderr);
+    }
+    if (error) {
+      throw error;
+    }
+    throw new Error(`git command failed: ${error.toString()}`);
   }
   return stdout.toString().trim();
 }
diff --git a/package.json b/package.json
index b5a0e8d760cf..1a8f460719bc 100644
--- a/package.json
+++ b/package.json
@@ -13,8 +13,8 @@
     "test": "yarn prettier-check && yarn test:client && yarn test:kumascript && yarn test:testing",
     "build:client": "cd client && cross-env INLINE_RUNTIME_CHUNK=false react-scripts build",
     "build:ssr": "cd ssr && webpack --config webpack.config.js --mode=production",
-    "prepare-build": "yarn build:client && yarn build:ssr && yarn tool gather-git-history",
-    "build": "cd build && cross-env NODE_ENV=production node cli.js",
+    "prepare-build": "yarn build:client && yarn build:ssr && yarn tool gather-git-history --verbose",
+    "build": "cross-env NODE_ENV=production node build/cli.js",
     "start": "(test -f client/build/index.html || yarn build:client) && (test -f ssr/dist/main.js || yarn build:ssr) && nf -j Procfile.start start",
     "dev": "yarn build:client && yarn build:ssr && nf -j Procfile.dev start",
     "start:client": "cd client && cross-env BROWSER=none PORT=3000 react-scripts start",
diff --git a/testing/.env b/testing/.env
index cb0ba74d109e..4c31075fc376 100644
--- a/testing/.env
+++ b/testing/.env
@@ -5,8 +5,8 @@
 # The relative path trick is necessary because `yarn build` will
 # be running from the `./build/` directory.
 
-CONTENT_ROOT=../testing/content/files
-CONTENT_ARCHIVED_ROOT=../testing/archived-content/files
+CONTENT_ROOT=testing/content/files
+CONTENT_ARCHIVED_ROOT=testing/archived-content/files
 
 # Because you never benefit from the progressbar when doing mass builds in
 # testing environment. And in CI, it's always disabled anyway.

From 68f6f1d350a1745c59802a208ce3dc6832149a1f Mon Sep 17 00:00:00 2001
From: Peter Bengtsson <mail@peterbe.com>
Date: Mon, 9 Nov 2020 20:22:10 -0500
Subject: [PATCH 6/9] comment

---
 build/git-history.js | 1 +
 content/utils.js     | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/build/git-history.js b/build/git-history.js
index 152b5e705a8f..f737bb87e1d7 100644
--- a/build/git-history.js
+++ b/build/git-history.js
@@ -41,6 +41,7 @@ function getFromGit(contentRoot = CONTENT_ROOT) {
   }
   return map;
 }
+
 function gather(contentRoot, previousFile = null) {
   const map = new Map();
   if (previousFile) {
diff --git a/content/utils.js b/content/utils.js
index 9b6925381791..2eecbb6fee1f 100644
--- a/content/utils.js
+++ b/content/utils.js
@@ -84,6 +84,8 @@ function execGit(args, opts = {}, root = null) {
     args,
     {
       cwd: gitRoot,
+      // Default is 1MB
+      // That's rarely big enough for what we're using Yari for.
       maxBuffer: 1024 * 1024 * 100, // 100MB
     }
   );

From 1648bbf8f21d0be1febecdb1e05943745d99820c Mon Sep 17 00:00:00 2001
From: Peter Bengtsson <mail@peterbe.com>
Date: Mon, 9 Nov 2020 20:26:18 -0500
Subject: [PATCH 7/9] use the -z trick

---
 build/git-history.js | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/build/git-history.js b/build/git-history.js
index f737bb87e1d7..4236246d3748 100644
--- a/build/git-history.js
+++ b/build/git-history.js
@@ -17,6 +17,9 @@ function getFromGit(contentRoot = CONTENT_ROOT) {
       `--format=${MARKER}%cI`,
       "--date-order",
       "--reverse",
+      // "Separate the commits with NULs instead of with new newlines."
+      // So each line isn't, possibly, wrapped in "quotation marks".
+      "-z",
     ],
     {
       cwd: repoRoot,
@@ -26,12 +29,7 @@ function getFromGit(contentRoot = CONTENT_ROOT) {
 
   const map = new Map();
   let date = null;
-  for (let line of output.split("\n")) {
-    // Happens to file paths that contain non-ascii or control charaters.
-    // E.g. "files/en-us/glossary/b\303\251zier_curve/index.html"
-    if (line.startsWith('"') && line.endsWith('"')) {
-      line = line.slice(1, -1);
-    }
+  for (let line of output.split("\0")) {
     if (line.startsWith(MARKER)) {
       date = new Date(line.replace(MARKER, ""));
     } else if (line) {

From f2768d26b0495df5651301369017a26d003e5847 Mon Sep 17 00:00:00 2001
From: Peter Bengtsson <mail@peterbe.com>
Date: Mon, 9 Nov 2020 20:34:14 -0500
Subject: [PATCH 8/9] update comment

---
 build/git-history.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/build/git-history.js b/build/git-history.js
index 4236246d3748..de0f276b7973 100644
--- a/build/git-history.js
+++ b/build/git-history.js
@@ -19,6 +19,7 @@ function getFromGit(contentRoot = CONTENT_ROOT) {
       "--reverse",
       // "Separate the commits with NULs instead of with new newlines."
       // So each line isn't, possibly, wrapped in "quotation marks".
+      // Now we just need to split the output, as a string, by \0.
       "-z",
     ],
     {

From be65c0b6b746de7adc112ca7cc60990f5e1a76ce Mon Sep 17 00:00:00 2001
From: Peter Bengtsson <mail@peterbe.com>
Date: Mon, 9 Nov 2020 20:51:11 -0500
Subject: [PATCH 9/9] better testing

---
 content/utils.js               | 1 +
 testing/tests/headless.test.js | 1 +
 testing/tests/index.test.js    | 1 +
 3 files changed, 3 insertions(+)

diff --git a/content/utils.js b/content/utils.js
index 2eecbb6fee1f..d07a1ab9274e 100644
--- a/content/utils.js
+++ b/content/utils.js
@@ -91,6 +91,7 @@ function execGit(args, opts = {}, root = null) {
   );
   if (error || status !== 0) {
     if (stderr) {
+      console.log(`Error running git ${args}`);
       console.error(stderr);
     }
     if (error) {
diff --git a/testing/tests/headless.test.js b/testing/tests/headless.test.js
index c5fe5af1a351..85a99c0eee16 100644
--- a/testing/tests/headless.test.js
+++ b/testing/tests/headless.test.js
@@ -20,6 +20,7 @@ describe("Basic viewing of functional pages", () => {
   it("open the /en-US/docs/Web/Foo page", async () => {
     await page.goto(testURL("/en-US/docs/Web/Foo"));
     await expect(page).toMatch("<foo>: A test tag");
+    await expect(page).toMatchElement(".document-meta time", { visible: true });
   });
 
   it("open the /en-US/docs/Web/InteractiveExample page", async () => {
diff --git a/testing/tests/index.test.js b/testing/tests/index.test.js
index 238cebb72c21..a6ea54cbbfc6 100644
--- a/testing/tests/index.test.js
+++ b/testing/tests/index.test.js
@@ -20,6 +20,7 @@ test("content built foo page", () => {
   expect(doc.pageTitle).toBe(`${doc.title} | MDN`);
   expect(doc.summary).toBe("This becomes the summary.");
   expect(doc.mdn_url).toBe("/en-US/docs/Web/Foo");
+  expect(new Date(doc.modified)).toBeTruthy();
   expect(doc.source).toBeTruthy();
 
   expect(doc.flaws.macros.length).toBe(6);