fix(build): address @ionic/angular bundle size issue (#5705)

This fixes an issue where when @ionic/angular was built using Stencil
and then used in an angular project it would produce much larger bundle
sizes than it had previously. This issue started appearing in Stencil
v4.17.x, after we switched to using esbuild for our production builds.

The issue occurred because of how bundles in `internal/` were depending
on code in `mock-doc/`. In particular, in `src/runtime/dom-extras.ts` we
had an import from `@stencil/core/mock-doc`. In our bundles this was
being correctly externalized, so that `internal/client/index.js` for
instance would import from `'../../mock-doc/index.cjs'`, but the problem
is that when an Angular project then tried to bundle this file later it
would not tree-shake the import properly and the whole contents of
mock-doc would be injected into the bundle, bloating it by 400kb or so.

This is because esbuild, which `ng build` uses under the hood, does not
support tree-shaking in commonjs modules. See here for details:

https://esbuild.github.io/api/#tree-shaking

The simplest fix for this is to add the `NODE_TYPES` enum to
`src/utils/constants.ts` so that the runtime does not need to have any
dependency on `mock-doc` at all.

Author: alicewriteswrongs

scripts/esbuild/internal-platform-client.ts

@@ -17,7 +17,7 @@ import { externalAlias, getBaseEsbuildOptions, getEsbuildAliases, getEsbuildExte
  * @param opts build options
  * @returns an array of ESBuild option objects
  */
-export async function getInternalClientBundle(opts: BuildOptions): Promise<ESBuildOptions[]> {
+export async function getInternalClientBundles(opts: BuildOptions): Promise<ESBuildOptions[]> {
   const inputClientDir = join(opts.srcDir, 'client');
   const outputInternalClientDir = join(opts.output.internalDir, 'client');
   const outputInternalClientPolyfillsDir = join(outputInternalClientDir, 'polyfills');
@@ -59,9 +59,6 @@ export async function getInternalClientBundle(opts: BuildOptions): Promise<ESBui
       replace(createReplaceData(opts)),
       externalAlias('@app-data', '@stencil/core/internal/app-data'),
       externalAlias('@utils/shadow-css', './shadow-css.js'),
-      // we want to get the esm, not the cjs, since we're creating an esm
-      // bundle here
-      externalAlias('@stencil/core/mock-doc', '../../mock-doc/index.js'),
       findAndReplaceLoadModule(),
     ],
   };

scripts/esbuild/internal-platform-hydrate.ts

@@ -35,7 +35,7 @@ export async function getInternalPlatformHydrateBundles(opts: BuildOptions): Pro
 
   const hydratePlatformInput = join(hydrateSrcDir, 'platform', 'index.js');
 
-  const external = [...getEsbuildExternalModules(opts, outputInternalHydrateDir), '@stencil/core/mock-doc'];
+  const external = getEsbuildExternalModules(opts, outputInternalHydrateDir);
 
   const internalHydrateAliases = getEsbuildAliases();
   internalHydrateAliases['@platform'] = hydratePlatformInput;
@@ -54,8 +54,6 @@ export async function getInternalPlatformHydrateBundles(opts: BuildOptions): Pro
     plugins: [
       externalAlias('@utils/shadow-css', '../client/shadow-css.js'),
       externalAlias('@app-data', '@stencil/core/internal/app-data'),
-      // this needs to be externalized and also pointed at the esm version
-      externalAlias('@stencil/core/mock-doc', '../../mock-doc/index.js'),
     ],
   };
 

scripts/esbuild/internal-platform-testing.ts

@@ -33,7 +33,7 @@ export async function getInternalTestingBundle(opts: BuildOptions): Promise<ESBu
     '@platform': inputTestingPlatform,
   };
 
-  const external = [...getEsbuildExternalModules(opts, opts.output.internalDir), '@stencil/core/mock-doc'];
+  const external = getEsbuildExternalModules(opts, opts.output.internalDir);
 
   const internalTestingBuildOptions: ESBuildOptions = {
     ...getBaseEsbuildOptions(),

scripts/esbuild/internal.ts

@@ -6,7 +6,7 @@ import { copyStencilInternalDts } from '../bundles/internal';
 import type { BuildOptions } from '../utils/options';
 import { writePkgJson } from '../utils/write-pkg-json';
 import { getInternalAppDataBundles } from './internal-app-data';
-import { getInternalClientBundle } from './internal-platform-client';
+import { getInternalClientBundles } from './internal-platform-client';
 import { getInternalPlatformHydrateBundles } from './internal-platform-hydrate';
 import { getInternalTestingBundle } from './internal-platform-testing';
 import { getBaseEsbuildOptions, runBuilds } from './util';
@@ -53,13 +53,13 @@ export async function buildInternal(opts: BuildOptions) {
     platform: 'node',
   };
 
-  const clientPlatformBundle = await getInternalClientBundle(opts);
+  const clientPlatformBundles = await getInternalClientBundles(opts);
   const hydratePlatformBundles = await getInternalPlatformHydrateBundles(opts);
   const appDataBundles = await getInternalAppDataBundles(opts);
   const internalTestingBundle = await getInternalTestingBundle(opts);
 
   return runBuilds(
-    [shadowCSSBundle, ...clientPlatformBundle, ...hydratePlatformBundles, internalTestingBundle, ...appDataBundles],
+    [shadowCSSBundle, ...clientPlatformBundles, ...hydratePlatformBundles, internalTestingBundle, ...appDataBundles],
     opts,
   );
 }

src/runtime/dom-extras.ts

@@ -1,7 +1,6 @@
 import { BUILD } from '@app-data';
 import { getHostRef, plt, supportsShadow } from '@platform';
-import { NODE_TYPES } from '@stencil/core/mock-doc';
-import { CMP_FLAGS, HOST_FLAGS } from '@utils';
+import { CMP_FLAGS, HOST_FLAGS, NODE_TYPES } from '@utils/constants';
 
 import type * as d from '../declarations';
 import { PLATFORM_FLAGS } from './runtime-constants';

src/utils/constants.ts

@@ -231,3 +231,28 @@ export const VALID_CONFIG_OUTPUT_TARGETS = [
 ] as const;
 
 export const GENERATED_DTS = 'components.d.ts';
+
+/**
+ * DOM Node types
+ *
+ * See https://developer.mozilla.org/en-US/docs/Web/API/Node/nodeType
+ *
+ * Note: this is a duplicate of the `NODE_TYPES` enum in mock-doc, it's
+ * copied over here so that we do not need to introduce a dependency on the
+ * mock-doc bundle in the runtime. See
+ * https://github.com/ionic-team/stencil/pull/5705 for more details.
+ */
+export const enum NODE_TYPES {
+  ELEMENT_NODE = 1,
+  ATTRIBUTE_NODE = 2,
+  TEXT_NODE = 3,
+  CDATA_SECTION_NODE = 4,
+  ENTITY_REFERENCE_NODE = 5,
+  ENTITY_NODE = 6,
+  PROCESSING_INSTRUCTION_NODE = 7,
+  COMMENT_NODE = 8,
+  DOCUMENT_NODE = 9,
+  DOCUMENT_TYPE_NODE = 10,
+  DOCUMENT_FRAGMENT_NODE = 11,
+  NOTATION_NODE = 12,
+}

tsconfig.json

@@ -40,6 +40,7 @@
       "@stencil/core/cli": ["src/cli/index.ts"],
       "@sys-api-node": ["src/sys/node/index.ts"],
       "@utils": ["src/utils/index.ts"],
+      "@utils/*": ["src/utils/*"],
       "@utils/shadow-css": ["src/utils/shadow-css"]
     },
     "pretty": true,