Remove moment from extension bundles (#12685)

* Remove moment from bundle

* oops

build/ci/postInstall.js

@@ -161,9 +161,42 @@ function fixUIFabricForTS49() {
     });
 }
 
+/**
+ * Ensures that moment is not used by any other npm package other than @jupyterlab/coreutils.
+ * See comments here build/webpack/moment.js
+ */
+function verifyMomentIsOnlyUsedByJupyterLabCoreUtils() {
+    const packageLock = require(path.join(__dirname, '..', '..', 'package-lock.json'));
+    const packagesAllowedToUseMoment = ['node_modules/@jupyterlab/coreutils', '@jupyterlab/coreutils'];
+    const otherPackagesUsingMoment = [];
+    ['packages', 'dependencies'].forEach((key) => {
+        if (!(key in packageLock)) {
+            throw new Error(`Invalid package-lock.json, as it does not contain the key '${key}'`);
+        }
+        const packages = packageLock[key];
+        Object.keys(packages).forEach((packageName) => {
+            if (packagesAllowedToUseMoment.includes(packageName)) {
+                return;
+            }
+            ['dependencies', 'requires'].forEach((dependencyKey) => {
+                if (dependencyKey in packages[packageName]) {
+                    const dependenciesOfPackage = packages[packageName][dependencyKey];
+                    if ('moment' in dependenciesOfPackage) {
+                        otherPackagesUsingMoment.push(`${key}.${dependencyKey}.${packageName}`);
+                    }
+                }
+            });
+        });
+    });
+    if (otherPackagesUsingMoment.length > 0) {
+        throw new Error(`Moment is being used by another package (${otherPackagesUsingMoment.join(', ')}).`);
+    }
+}
+
 fixUIFabricForTS49();
 fixJupyterLabRenderers();
 makeVariableExplorerAlwaysSorted();
 createJupyterKernelWithoutSerialization();
 updateJSDomTypeDefinition();
 fixStripComments();
+verifyMomentIsOnlyUsedByJupyterLabCoreUtils();

build/webpack/moment.js

@@ -0,0 +1,27 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+// This file has been handcrafted to override the use of moment.js.
+// Moment is only used in @jupyterlab/coreutils/lib/time.js
+// & that code is not used anywhere in any code path.
+// Hence we create a dummy moment object that does nothing.
+// & we have checks on CI that ensures no other npm package or other code does not in-directly or directly use moment.
+
+export default function (dateTime) {
+    return {
+        formatNow: () => {
+            try {
+                return dateTime.toLocaleString();
+            } catch {
+                return `${dateTime}`;
+            }
+        },
+        format: () => {
+            try {
+                return dateTime.toLocaleTimeString();
+            } catch {
+                return `${dateTime}`;
+            }
+        }
+    };
+}

build/webpack/webpack.extension.node.config.js

@@ -130,10 +130,6 @@ const config = {
         new copyWebpackPlugin({ patterns: [{ from: './node_modules/zeromq/**/*.json' }] }),
         new copyWebpackPlugin({ patterns: [{ from: './node_modules/node-gyp-build/**/*' }] }),
         new copyWebpackPlugin({ patterns: [{ from: './node_modules/@vscode/jupyter-ipywidgets7/dist/*.js' }] }),
-        new webpack.IgnorePlugin({
-            resourceRegExp: /^\.\/locale$/,
-            contextRegExp: /moment$/
-        }),
         new webpack.DefinePlugin({
             IS_PRE_RELEASE_VERSION_OF_JUPYTER_EXTENSION: JSON.stringify(
                 typeof process.env.IS_PRE_RELEASE_VERSION_OF_JUPYTER_EXTENSION === 'string'
@@ -147,7 +143,8 @@ const config = {
             // Pointing pdfkit to a dummy js file so webpack doesn't fall over.
             // Since pdfkit has been externalized (it gets updated with the valid code by copying the pdfkit files
             // into the right destination).
-            pdfkit: path.resolve(__dirname, 'pdfkit.js')
+            pdfkit: path.resolve(__dirname, 'pdfkit.js'),
+            moment: path.join(__dirname, 'moment.js')
         },
         extensions: ['.ts', '.js'],
         plugins: [new tsconfig_paths_webpack_plugin.TsconfigPathsPlugin({ configFile: configFileName })],

build/webpack/webpack.extension.web.config.js

@@ -114,10 +114,6 @@ const config = {
             )
         }),
         new CleanTerminalPlugin(),
-        new webpack.IgnorePlugin({
-            resourceRegExp: /^\.\/locale$/,
-            contextRegExp: /moment$/
-        }),
         new webpack.optimize.LimitChunkCountPlugin({
             maxChunks: 1
         })
@@ -130,7 +126,8 @@ const config = {
         ],
         alias: {
             // provides alternate implementation for node module and source files
-            fs: './fs-empty.js'
+            fs: './fs-empty.js',
+            moment: path.join(__dirname, 'moment.js')
         },
         fallback: {
             os: require.resolve('os-browserify')