From f33457a0addc3f4bf0c6cbf008f69b98f22a9cd4 Mon Sep 17 00:00:00 2001
From: Ben Newman <ben@meteor.com>
Date: Mon, 13 Nov 2017 16:54:38 -0500
Subject: [PATCH] Server-render es5-shim <script> tags like sockjs-shim.

Just as we were able to remove the SockJS polyfill library entirely from
the client JS bundle for modern browsers (#9353), we can do the same with
the `es5-shim` package.

The removes 28KB from the size of the minified JS bundle (before gzip).

It is no longer necessary for other packages to register weak dependencies
on `es5-shim`, because `es5-shim` will be reliably loaded in the `<head>`
if installed, which guarantees it will be evaluated before any bundled JS
in packages or the application.

In addition to loading `es5-shim` and `es5-sham` using `<script>` tags on
the client, we no longer evaluate either script on the server, since Node
8 has solid support for everything that previously needed shimming.
---
 packages/babel-runtime/package.js             |  4 --
 packages/ecmascript-runtime-client/package.js |  4 --
 packages/es5-shim/client.js                   |  5 ---
 packages/es5-shim/es5-sham.js                 |  1 +
 packages/es5-shim/es5-sham.min.js             |  1 +
 packages/es5-shim/es5-shim.js                 |  1 +
 packages/es5-shim/es5-shim.min.js             |  1 +
 packages/es5-shim/export_globals.js           | 18 --------
 packages/es5-shim/import_globals.js           | 14 -------
 packages/es5-shim/package.js                  |  9 +++-
 packages/es5-shim/server.js                   | 42 +++++++++++++++++--
 packages/sockjs-shim/server.js                | 31 +++++++-------
 12 files changed, 68 insertions(+), 63 deletions(-)
 delete mode 100644 packages/es5-shim/client.js
 create mode 120000 packages/es5-shim/es5-sham.js
 create mode 120000 packages/es5-shim/es5-sham.min.js
 create mode 120000 packages/es5-shim/es5-shim.js
 create mode 120000 packages/es5-shim/es5-shim.min.js
 delete mode 100644 packages/es5-shim/export_globals.js
 delete mode 100644 packages/es5-shim/import_globals.js
diff --git a/packages/babel-runtime/package.js b/packages/babel-runtime/package.js
index 8eb9322e7e..2492ebacc8 100644
--- a/packages/babel-runtime/package.js
+++ b/packages/babel-runtime/package.js
@@ -10,10 +10,6 @@ Npm.depends({
 });
 
 Package.onUse(function (api) {
-  // If the es5-shim package is installed, make sure it loads before
-  // babel-runtime, since babel-runtime uses some ES5 APIs like
-  // Object.defineProperties that are buggy in older browsers.
-  api.use("es5-shim", { weak: true });
   api.use("modules");
   api.use("promise"); // Needed by Regenerator.
   api.mainModule("babel-runtime.js");
diff --git a/packages/ecmascript-runtime-client/package.js b/packages/ecmascript-runtime-client/package.js
index ec764de087..6e8094aa75 100644
--- a/packages/ecmascript-runtime-client/package.js
+++ b/packages/ecmascript-runtime-client/package.js
@@ -7,10 +7,6 @@ Package.describe({
 });
 
 Package.onUse(function(api) {
-  // If the es5-shim package is installed, make sure it loads before
-  // ecmascript-runtime-server, since the runtime uses some ES5 APIs like
-  // Object.defineProperties that are buggy in older browsers.
-  api.use("es5-shim", { weak: true });
   api.use("modules", "client");
   api.use("promise", "client");
   api.mainModule("runtime.js", "client");
diff --git a/packages/es5-shim/client.js b/packages/es5-shim/client.js
deleted file mode 100644
index aa0d54b091..0000000000
--- a/packages/es5-shim/client.js
+++ /dev/null
@@ -1,5 +0,0 @@
-require("./import_globals.js");
-require("es5-shim/es5-shim.js");
-require("es5-shim/es5-sham.js");
-require("./console.js");
-require("./export_globals.js");
diff --git a/packages/es5-shim/es5-sham.js b/packages/es5-shim/es5-sham.js
new file mode 120000
index 0000000000..7141213920
--- /dev/null
+++ b/packages/es5-shim/es5-sham.js
@@ -0,0 +1 @@
+.npm/package/node_modules/es5-shim/es5-sham.js
\ No newline at end of file
diff --git a/packages/es5-shim/es5-sham.min.js b/packages/es5-shim/es5-sham.min.js
new file mode 120000
index 0000000000..ddad4e73ea
--- /dev/null
+++ b/packages/es5-shim/es5-sham.min.js
@@ -0,0 +1 @@
+.npm/package/node_modules/es5-shim/es5-sham.min.js
\ No newline at end of file
diff --git a/packages/es5-shim/es5-shim.js b/packages/es5-shim/es5-shim.js
new file mode 120000
index 0000000000..563c36fe3d
--- /dev/null
+++ b/packages/es5-shim/es5-shim.js
@@ -0,0 +1 @@
+.npm/package/node_modules/es5-shim/es5-shim.js
\ No newline at end of file
diff --git a/packages/es5-shim/es5-shim.min.js b/packages/es5-shim/es5-shim.min.js
new file mode 120000
index 0000000000..20991ff43b
--- /dev/null
+++ b/packages/es5-shim/es5-shim.min.js
@@ -0,0 +1 @@
+.npm/package/node_modules/es5-shim/es5-shim.min.js
\ No newline at end of file
diff --git a/packages/es5-shim/export_globals.js b/packages/es5-shim/export_globals.js
deleted file mode 100644
index dcf38e47c8..0000000000
--- a/packages/es5-shim/export_globals.js
+++ /dev/null
@@ -1,18 +0,0 @@
-if (global.Date !== Date) {
-  global.Date = Date;
-}
-
-if (global.parseInt !== parseInt) {
-  global.parseInt = parseInt;
-}
-
-if (global.parseFloat !== parseFloat) {
-  global.parseFloat = parseFloat;
-}
-
-var Sp = String.prototype;
-if (Sp.replace !== originalStringReplace) {
-  // Restore the original value of String#replace, because the es5-shim
-  // reimplementation is buggy. See also import_globals.js.
-  Sp.replace = originalStringReplace;
-}
diff --git a/packages/es5-shim/import_globals.js b/packages/es5-shim/import_globals.js
deleted file mode 100644
index 6c7fa12759..0000000000
--- a/packages/es5-shim/import_globals.js
+++ /dev/null
@@ -1,14 +0,0 @@
-// Because the es5-{shim,sham}.js code assigns to Date and parseInt,
-// Meteor treats them as package variables, and so declares them as
-// variables in package scope, which causes some references to Date and
-// parseInt in the shim/sham code to refer to those undefined package
-// variables. The simplest solution seems to be to initialize the package
-// variables to their appropriate global values.
-Date = global.Date;
-parseInt = global.parseInt;
-parseFloat = global.parseFloat;
-
-// Save the original String#replace method, because es5-shim's
-// reimplementation of it causes problems in markdown/showdown.js.
-// This original method will be restored in export_globals.js.
-originalStringReplace = String.prototype.replace;
diff --git a/packages/es5-shim/package.js b/packages/es5-shim/package.js
index e114a1b51a..4bf5e92585 100644
--- a/packages/es5-shim/package.js
+++ b/packages/es5-shim/package.js
@@ -11,6 +11,13 @@ Npm.depends({
 
 Package.onUse(function(api) {
   api.use("modules");
-  api.mainModule("client.js", "client");
+  api.use("server-render");
+  api.mainModule("console.js", "client");
   api.mainModule("server.js", "server");
+  api.addAssets([
+    "es5-shim.js",
+    "es5-shim.min.js",
+    "es5-sham.js",
+    "es5-sham.min.js",
+  ], "client");
 });
diff --git a/packages/es5-shim/server.js b/packages/es5-shim/server.js
index 9731c36c32..09afb4b4e9 100644
--- a/packages/es5-shim/server.js
+++ b/packages/es5-shim/server.js
@@ -1,3 +1,39 @@
-require("./import_globals.js");
-require("es5-shim/es5-shim.js");
-require("./export_globals.js");
+const { onPageLoad } = require("meteor/server-render");
+
+const hasOwn = Object.prototype.hasOwnProperty;
+const minimumMajorVersions = {
+  chrome: 23,
+  firefox: 21,
+  ie: 10,
+  safari: 6,
+  phantomjs: 2,
+};
+
+onPageLoad(sink => {
+  if (doNotNeedShim(sink.request)) {
+    return;
+  }
+
+  sink.appendToHead(makeScript("shim"));
+  sink.appendToHead(makeScript("sham"));
+});
+
+function doNotNeedShim(request) {
+  const { browser, url } = request;
+  const query = url && url.query;
+  const forceEs5Shim = query && query.force_es5_shim;
+  if (! forceEs5Shim &&
+      browser &&
+      hasOwn.call(minimumMajorVersions, browser.name) &&
+      browser.major >= minimumMajorVersions[browser.name]) {
+    return true;
+  }
+  return false;
+}
+
+function makeScript(kind) {
+  return '\n<script src="/packages/es5-shim/es5-' +
+    kind + (
+      Meteor.isProduction ? ".min.js" : ".js"
+    ) + '"></script>';
+}
diff --git a/packages/sockjs-shim/server.js b/packages/sockjs-shim/server.js
index d12e6d99c8..7338ac52fa 100644
--- a/packages/sockjs-shim/server.js
+++ b/packages/sockjs-shim/server.js
@@ -1,11 +1,6 @@
 import { onPageLoad } from "meteor/server-render";
 
 const sockjsVersion = "0.3.4";
-const scriptPath =
-  "/packages/sockjs-shim/sockjs-" +
-  sockjsVersion +
-  (Meteor.isProduction ? ".min.js" : ".js");
-
 const hasOwn = Object.prototype.hasOwnProperty;
 const minimumMajorVersions = {
   chrome: 16,
@@ -16,21 +11,29 @@ const minimumMajorVersions = {
 };
 
 onPageLoad(sink => {
-  const {
-    browser,
-    url,
-  } = sink.request;
+  if (doNotNeedShim(sink.request)) {
+    return;
+  }
 
+  sink.appendToHead(makeScript(sockjsVersion));
+});
+
+function doNotNeedShim(request) {
+  const { browser, url } = request;
   const query = url && url.query;
   const forceSockJs = query && query.force_sockjs;
   if (! forceSockJs &&
       browser &&
       hasOwn.call(minimumMajorVersions, browser.name) &&
       browser.major >= minimumMajorVersions[browser.name]) {
-    return;
+    return true;
   }
+  return false;
+}
 
-  sink.appendToHead(
-    '<script src="' + scriptPath + '"></script>'
-  );
-});
+function makeScript(version) {
+  return '\n<script src="/packages/sockjs-shim/sockjs-' +
+    version + (
+      Meteor.isProduction ? ".min.js" : ".js"
+    ) + '"></script>';
+}
